[Federal Register Volume 63, Number 31 (Tuesday, February 17, 1998)]
[Rules and Regulations]
[Pages 8032-8049]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-3838]



[[Page 8031]]

_______________________________________________________________________

Part V





Department of Transportation





_______________________________________________________________________



Federal Aviation Administration



_______________________________________________________________________



14 CFR Parts 25 and 121



Revised Standards for Cargo or Baggage Compartments in Transport 
Category Airplanes; Final Rule

  Federal Register / Vol. 63, No. 31 / Tuesday, February 17, 1998 / 
Rules and Regulations  

[[Page 8032]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 25 and 121

[Docket No. 28937, Amdt Nos. 25-93 and 121-269]
RIN 2120-AG42


Revised Standards for Cargo or Baggage Compartments in Transport 
Category Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: These amendments upgrade the fire safety standards for cargo 
or baggage compartments in certain transport category airplanes by 
eliminating Class D compartments as an option for future type 
certification. Compartments that can no longer be designated as Class D 
must meet the standards for Class C or Class E compartments, as 
applicable. The Class D compartments in certain transport category 
airplanes manufactured under existing type certificates and used in 
passenger service must meet the fire or smoke detection and fire 
suppression standards for Class C compartments by early 2001 for use in 
air carrier, or most other commercial service. The Class D compartments 
in certain transport category airplanes manufactured under existing 
type certificates and used only for the carriage of cargo must also 
meet such standards or the corresponding standards for Class E 
compartments by that date for such service. These improved standards 
are adopted to increase protection from possible in-flight fires.
    The FAA also requests additional comments concerning specific 
issues related to transport category airplanes used by part 135 
operators. Those issues are enumerated under the section entitled 
Request for Comments.

DATES: Effective March 19, 1998. Additional comments, as requested in 
the section entitled Request for Comment, must be received on or before 
June 17, 1998.

ADDRESSES: Additional comments on the specific issues identified under 
the section entitled Request for Comments may be mailed in duplicate 
to: Federal Aviation Administration, Office of the Chief Counsel, 
Attention: Rules Docket (AGC-200), Docket No. 28937, 800 Independence 
Avenue, SW, Washington, DC 20591, or delivered in person to Room 915G 
at the same address. Comments delivered must be marked: Docket 28937. 
Comments may also be submitted electronically to 9-nprm-
[email protected]. Comments may be inspected in Room 915G weekdays, 
except Federal holidays, between 8:30 a.m. and 5:00 p.m. In addition, 
the FAA is maintaining an information docket of comments in the 
Transport Airplane Directorate (ANM-100), Federal Aviation 
Administration, 1601 Lind Avenue, SW, Renton, Washington 98055-4056. 
Comments in the information docket may be inspected in the Transport 
Airplane Directorate weekdays, except Federal holidays, between 7:30 
a.m. and 4:00 p.m.

FOR FURTHER INFORMATION CONTACT:
Gary L. Killion, Manager, Regulations Branch, ANM-114, Transport 
Airplane Directorate, Aircraft Certification Service, FAA, 1601 Lind 
Ave., SW, Renton, Washington 98055-4056; telephone (425) 227-2114.

SUPPLEMENTARY INFORMATION:

Availability of Final Rule

    This document may be downloaded from the FAA regulations section of 
the FedWorld electronic bulletin board (telephone: 703-321-3339) or the 
Federal Register's electronic bulletin board (telephone: 202-512-1661). 
Internet users may access the FAA's web page at http://www.faa.gov or 
the Federal Register's web page at http://www.access.gpo.gov/su__docs 
to download recently published rulemaking documents.
    Any person may obtain a copy of this final rule by submitting a 
request to the Federal Aviation Administration, Office of Rulemaking, 
ARM-1, 800 Independence Avenue, SW., Washington, DC 20591, or by 
calling (202) 267-9680. Communications must reference the amendment 
number or docket number of this final rule.
    Persons interested in being placed on the mailing list for future 
Notices of Proposed Rulemaking and Final Rules should request a copy of 
Advisory Circular (AC) No. 11-2A, Notice of Proposed Rulemaking 
Distribution System, which describes the application procedure.

Small Entity Inquiries

    The Small Business Regulatory Enforcement Fairness Act of 1996 
(SBREFA) requires the FAA to report inquiries from small entities 
concerning information on, and advice about, compliance with statutes 
and regulations within the FAA's jurisdiction, including interpretation 
and application of the law to specific sets of facts supplied by a 
small entity.
    The FAA's definitions of small entities may be accessed through the 
FAA's web page htt//www/faa.gov/avr/arm/sbrefa.htm, by contacting a 
local FAA official, or by contacting the FAA's Small Entity Contact 
listed below.
    If you are a small entity and have a question, contact your local 
FAA official. If you do not know how to contact your local FAA 
official, you may contact Charlene Brown, Program Analyst Staff, Office 
of Rulemaking, ARM-27, Federal Aviation Administration, 800 
Independence Avenue, SW., Washington, DC 20591, 1-888-551-1594. 
Internet users can find additional information on SBREFA in the ``Quick 
Jump'' section of the FAA's web page at http://www.faa.gov and may send 
electronic inquiries to the following Internet address: 9-AWA-
[email protected].

Background

    These amendments are based on Notice of Proposed Rulemaking No. 97-
10 (62 FR 32412, June 13, 1997). As discussed in Notice 97-10, there 
have been a number of fires in the cargo or baggage compartments of 
transport category airplanes in recent years, some of which have 
resulted in accidents and loss of life. Although the FAA had already 
taken action to improve the safety of these compartments by improving 
the fire-resistance of liners, the continuing occurrence of fires and 
the seriousness of the consequences of an uncontrolled fire resulted in 
a review of the entire cargo compartment classification system.
    During the early post-World War II period, it was recognized that 
timely detection of a fire by a crewmember of the airplane while at his 
or her station and prompt control of the fire when detected were 
necessary for protection of the airplane from a fire originating in a 
cargo or baggage compartment. Because the requirements for detection 
and extinguishment varied depending on the type and location of the 
compartment, a classification system was established. Three classes of 
cargo or baggage compartments were initially established and defined in 
1946 (Amendment 04-1 to part 04 of the Civil Air Regulations (CAR) 
effective November 1, 1946) as follows:

Class A

    A compartment in which the presence of a fire would be easily 
discovered by a crewmember while at his or her station, and of which 
all parts are easily accessible in flight. This is typically a small 
compartment used for crew luggage, and located in the cockpit where a 
fire would be readily detected and extinguished by a crewmember. Due to 
the small size and location of the

[[Page 8033]]

compartment, and the relatively brief time needed to detect and 
extinguish a fire, a liner is not required to prevent the fire from 
spreading to other parts of the airplane or protect adjacent structure.

Class B

    A compartment with a separate, approved smoke or fire detection 
system to give warning at the pilot or flight engineer station and with 
sufficient access in flight to enable a crewmember to effectively reach 
any part of the compartment with a hand fire extinguisher. Smoke or 
fire detection systems must provide indication of a fire to the 
flightcrew. Because it has a smoke or fire detection system, a Class B 
compartment may be located in an area remote from any crewmember's 
station. Due to the potentially larger size of the compartment and the 
greater time interval likely to occur before a fire would be 
extinguished, a liner meeting the flame penetration standards of 
Sec. 25.855 and Part I of Appendix F of part 25 must be provided to 
prevent the fire from spreading to other areas of the airplane and to 
protect adjacent structure. Although Class B compartments are typically 
the large cargo portions of the cabins of airplanes carrying a 
combination of passengers and cargo (frequently referred to as 
``combi'' airplanes), there are also Class B compartments that are 
relatively small baggage compartments located within the pressurized 
portions of airplanes designed for executive transportation.

Class C

    As defined at the time of initial classification in 1946, any 
compartment that did not fall into either Class A or B was a Class C 
compartment. Class C compartments differ from Class B compartments 
primarily in that built-in extinguishing systems are required for 
control of fires in lieu of crewmember accessibility. As with Class B 
compartments, smoke or fire detection systems must be provided. Due to 
the use of a built-in extinguishing system and closer control of 
ventilating airflow, the distribution of extinguishing agent in a Class 
C compartment is considerably more uniform than in a Class B 
compartment. The volumes of Class C compartments in transport category 
airplanes currently used in domestic service range from approximately 
700 to 3,000 cubic feet.
    Later, two additional classes of cargo or baggage compartments were 
established and defined as follows:

Class D

    A compartment in which a fire would be completely contained without 
endangering the safety of the airplane or the occupants (Amendment 4b-6 
to part 4b of the CAR effective March 5, 1952). A Class D compartment 
is similar to a Class C compartment in that both may be located in 
areas that are not readily accessible to a crewmember. As originally 
defined in 1952, Class D compartments were required to have smoke or 
fire detection systems; however, that requirement was deleted shortly 
thereafter. In lieu of providing smoke or fire detection and 
extinguishment, Class D compartments are designed to control a fire by 
severely restricting the supply of available oxygen. Because an oxygen-
deprived fire might continue to smolder for the duration of a flight, 
the capability of the liner to resist flame penetration is especially 
important. A note following the definition of a Class D compartment 
stated, ``For compartments having a volume not in excess of 500 cubic 
feet, an airflow of not more than 1,500 cubic feet per hour is 
considered acceptable. For larger compartments, lesser airflow may be 
applicable.'' That note was interpreted to mean that a Class D 
compartment could not exceed 2,000 cubic feet in volume even if the 
leakage of air into the compartment was zero. The standards for Class D 
compartments were later amended (Amendment 25-60, 51 FR 18236, May 16, 
1986) to specifically limit the volume of those compartments to 1,000 
cubic feet; however, some previously-approved airplanes in air carrier 
service have Class D compartments as large as 1,630 cubic feet. Other 
airplanes designed for executive transportation, and also used in on-
demand service, have relatively small Class D compartments located 
outside the pressurized portions of the cabin.

Class E

    A cargo compartment of an airplane used only for the carriage of 
cargo (Amendment 4b-10 to part 4b of the CAR, adopted in 1959). A smoke 
or fire detection system is required. In lieu of providing 
extinguishment, means must be provided to shut off the flow of 
ventilating air to or within a Class E compartment. In addition, 
procedures, such as depressurizing a pressurized airplane, are 
stipulated to minimize the amount of oxygen available in the event a 
fire occurs in a Class E compartment. Typically, a Class E compartment 
is the entire cabin of an all-cargo airplane; however, Class E 
compartments may be located in other portions of the airplane. This, of 
course, does not preclude the installation of compartments of other 
classes in all-cargo airplanes.
    Prior to the adoption of Sec. 25.858 in 1980, fire or smoke 
detection systems that provided indication within five minutes were 
considered acceptable. In order to ensure that a fire would be detected 
in time to permit effective use of the means provided to control it, 
Sec. 25.858 was adopted at that time (Amendment 25-54, 45 FR 60173, 
September 11, 1980) to require the detection systems of Class B, C and 
E compartments to provide visual indication to the flightcrew within 
one minute of the start of the fire.
    It should be noted that the overhead storage areas and certain 
other areas in the cabins of passenger-carrying airplanes are 
considered ``stowage'' compartments rather than cargo or baggage 
compartments. They are therefore not required to meet these standards.
    Although the standards for Class A, B, C, or D compartments make no 
distinction between compartments used for the carriage of passengers' 
baggage and those used for cargo, most of the industry experience at 
the time they were classified was limited to the carriage of 
passengers' baggage. Furthermore, compartments seldom, if ever, 
exceeded 200 cubic feet in volume at that time.
    When first defined, Class D compartments were envisioned to be 
small compartments, although not as small as Class A compartments, and 
were to suppress a fire by severely restricting the amount of available 
oxygen. Later, however, larger Class D compartments were installed in 
transport category airplanes, increasing both the amount of potentially 
combustible material and the available oxygen. Although there is little 
or no flow of air into a Class D compartment at the time a fire occurs, 
there is oxygen available from the air already contained in the 
compartment. In some instances, particularly when the compartment is 
larger or only partially filled, the oxygen already present in the 
compartment may be sufficient to support an intense fire long enough 
for it to penetrate the liner. Once the integrity of the liner is 
compromised, there is an unlimited flow of air into the compartment, 
resulting in an uncontrollable fire that can quickly spread throughout 
the rest of the airplane.
    An uncontrollable fire of this nature did occur in 1980 when a 
Saudi Arabian Airlines Lockheed L-1011 was destroyed shortly after 
landing. The fire, which resulted in a loss of 301 lives, was reported 
to have started in a Class

[[Page 8034]]

D compartment. (The compartment in that airplane is sometimes described 
erroneously as a Class C compartment because it has smoke detection. 
During normal operation, the compartment has ventilating airflow 
greater than that generally acceptable for a Class D compartment in 
order to facilitate the carriage of live animals. When a fire is 
detected, the ventilating airflow is shut off to restrict the supply of 
oxygen. That compartment, therefore, functioned as a Class D 
compartment insofar as that fire is concerned.)
    The growing concern over this and other reports of cargo or baggage 
compartment fires led to the adoption of Amendment 25-60. In addition 
to establishing a maximum volume of 1,000 cubic feet for Class D 
compartments, Amendment 25-60 also established new standards for liners 
with greater resistance to flame penetration for use in Class C and D 
compartments. That amendment applies to transport category airplanes 
for which an application for type certificate is made on or after June 
16, 1985. Similar, but not identical, standards were also established 
for the liners of other transport category airplanes operated under the 
provisions of parts 121 or 135 (Amendments 121-202 and 135-31, 54 FR 
7384, February 17, 1989). Operators of those airplanes were required to 
install liners that meet the new standards by March 20, 1991. Unlike 
Amendment 25-60, Amendments 121-202 and 135-31 do not establish a 
maximum volume for Class D compartments. Also Amendment 25-60 applies 
to all Class C or D compartments regardless of size, while Amendments 
121-202 and 135-31 apply only to compartments greater than 200 cubic 
feet. The safety benefits that could be gained at that time by 
replacing existing liners in compartments smaller than 200 cubic feet 
were not considered sufficient to justify the cost of doing so. As 
discussed in greater detail below, the subsequent introduction of 
consumer aerosol cans with highly flammable propellants has introduced 
a hazard that did not exist at that time.
    A Boeing 737 operated by Gulf Air was destroyed in September 1983 
as a result of an inflight fire in a Class D compartment. The fire, 
which resulted in 112 casualties, was attributed to an incendiary 
device.
    In February 1988, a fire occurred in the Class D compartment of an 
American Airlines McDonnell Douglas MD-83. Although there was no loss 
of life, the fire severely damaged the cabin floor above the 
compartment. As a result, the FAA initiated a review of service 
experience and existing regulations, policies and procedures pertaining 
to the certification of airplanes with Class D compartments. From this 
review, it was determined that a dozen fires had occurred in Class D 
Compartments over the past two decades. The consequences of those fires 
ranged from no airplane damage and no occupant injury to complete 
destruction of the Saudi Arabian Airlines Lockheed L-1011, as discussed 
above.
    Since the time the review of Class D compartments was completed 
there have also been seven additional known instances of fires 
occurring in those compartments. Most resulted in no injuries and 
little or no damage to the airplane. The exception, insofar as injuries 
and damage are concerned, was the fire that occurred in May of 1996 in 
the Class D compartment of a McDonnell Douglas DC-9 operated by Valujet 
Airlines. Like the American Airlines MD-83 fire noted above, that fire 
involved the carriage of undeclared hazardous materials; however, 
unlike the MD-83 fire, it resulted in the destruction of the airplane 
with a loss of 110 lives. It must be noted that this undeclared 
shipment occurred in spite of existing prohibitions concerning such 
shipments.
    In the meantime, an additional potential hazard in the cargo or 
baggage compartments of passenger-carrying airplanes has been brought 
to light. Due to environmental concerns, the aerosol cans now 
manufactured for consumer use utilize a mixture of propane, butane and 
isobutane for propellants in lieu of the non-flammable gases previously 
used. Passengers are not prohibited from transporting such aerosol cans 
by the applicable hazardous materials rules, and they have become so 
widely used by the general public that a high percentage of the pieces 
of checked baggage contain at least one aerosol can. Tests conducted by 
the FAA Technical Center show that they can burst if they are in a 
burning suitcase. The tests further show that if the burst occurs in a 
non-inert atmosphere, such as that of a Class D compartment, there is 
immediate auto-ignition of the propellant. The accompanying explosion 
is of such force and intensity that the liner could be rendered 
ineffective in limiting the supply of oxygen to the fire. Because the 
liner would be damaged by the explosion rather than by flame 
penetration, the use of a liner meeting the newer standards of 
Amendment 25-60 would not provide protection from this hazard. With an 
unlimited supply of oxygen and the integrity of the liner compromised, 
there is no longer any effective means to prevent an uncontrollable 
fire from spreading to other parts of the airplane. If, on the other 
hand, the burst occurs in an inert atmosphere, such as that of a Class 
C compartment in which the extinguishing agent has been discharged, the 
propellant does not ignite and poses no further hazard. (As noted 
above, smoke or fire detectors are required to provide indication to 
the flightcrew within one minute after the start of a fire, allowing 
sufficient time in which to inert the compartment before aerosol cans 
would burst.) The results of these tests are contained in Report No. 
DOT/FAA/CT-89/32 entitled ``Fire Hazards of Aerosol Cans in Aircraft 
Cargo Compartments.'' A copy of that report was placed in the docket 
for examination by interested persons.
    In at least one instance, a cargo or baggage compartment fire 
resulted in the plastic cap being melted from an aerosol can. 
Fortuitously, however, none of the fires experienced since the time 
aerosol cans with flammable propellants were introduced were of such 
intensity or proximity to result in an aerosol can being ruptured.
    It must be noted that the probability that an ignition will occur 
is primarily a function of the flammability of the material being 
carried in the compartment and the sources of ignition; however, the 
consequences of a fire, once ignition has occurred, depend greatly on 
the fire-protection features of the compartment in which it occurs. The 
FAA is aware of at least four fires that have occurred in Class C 
compartments during the past decade--a rate of occurrence somewhat 
commensurate with that of fires occurring in Class D compartments. 
(Three of those fires involved U.S. air carriers.) In marked contrast 
to the fatalities that have occurred as a result of fires originating 
in Class D compartments, the FAA is not aware of any fatality that has 
occurred as a result of a fire originating in a Class C compartment.

Discussion

    As noted above, some Class D compartments are much larger than 
envisioned at the time they were originally defined. As a result, they 
typically contain considerably more combustible material than 
anticipated. Although there is little or no airflow into a Class D 
compartment at the time a fire occurs, there is oxygen available from 
the air already contained in the compartment. In some instances, 
particularly in the larger compartments or those that are only 
partially filled, this quantity of oxygen may be sufficient to support 
an intense fire long

[[Page 8035]]

enough for it to burn through the liner. If the integrity of the liner 
is compromised, there is an unlimited flow of oxygen into the 
compartment. With the liner no longer intact and an unlimited flow of 
oxygen supporting the fire, there is no means to prevent it from 
spreading rapidly throughout the airplane. Due to the widespread use of 
aerosol cans with highly flammable propellants, there is now a 
possibility that an explosion will destroy the liner integrity. A fire 
originating in a Class D compartment could, therefore, become 
uncontrollable very quickly. In view of these possibly catastrophic 
results, the FAA proposed in Notice 97-10 to amend past 25 to eliminate 
Class D compartments altogether. Compartments in passenger-carrying 
airplanes that could no longer be approved as Class D compartments 
would have to meet the standards of Class C compartments.
    Due to uncertainties concerning the availability of suitable 
suppression agents, as discussed in greater detail under Halon 
Considerations below, the FAA also considered the possibility of 
requiring only the installation of detection systems. Having a 
detection system would enable the flightcrew to abort a takeoff if an 
ignition occurred during the brief period before the airplane became 
airborne. If, on the other hand, the fire occurred after the airplane 
became airborne, which is more likely, the fire could burn out of 
control before a safe landing could be made. (This, of course, refers 
to compartments other than Class E. As discussed below, Class E 
compartments are required to have means other than extinguishing 
systems to control any fire that may occur.) In that regard, it should 
be noted that 301 lives were lost in the Saudi Arabian Lockheed L-1011 
fire described above even though the compartment did, in fact, have a 
detection system. Since the installation of detection systems alone 
would provide only a small incremental increase in safety, it is 
essential that both detection and suppression systems be provided for 
these compartments.
    As discussed above, Class E compartments may be installed in 
airplanes used only for the carriage of cargo. As in the case of a 
Class C compartment, a smoke or fire detection system is required for a 
Class E compartment. In lieu of providing an extinguishing system, as 
required for a Class C compartment, means must be provided to shut off 
the flow of ventilating air to or within a Class E compartment. In 
addition, procedures, such as depressurizing the airplane, are 
stipulated to further minimize the amount of oxygen available in the 
event a fire occurs in a Class E compartments could be shown to meet 
the standards of Class E compartments in lieu of those for Class C 
compartments. The installation of smoke r fire detection systems and 
the means provided to minimize the amount of oxygen in Class E 
compartments would provide an improvement in safety for compartments 
presently designated as Class D and installed in all-cargo airplanes. 
The benefit from that improvement in the safety of operation of all-
cargo airplanes would be commensurate with the cost of converting Class 
D compartments to Class E compartments.
    Part 25 contains an inconsistency between the terminology used in 
Sec. 25.857 and that of Sec. 25.858. The former refers to a ``smoke 
detector or fire detector system'' for Class B, C or E compartments 
while the latter refers to compartments with ``fire detection 
provisions.'' Smoke detectors are, of course, a form of fire detectors 
since the purpose of installing a smoke detection system is to detect a 
fire. Nevertheless, the use of different terminology in the two 
sections may cause confusion. For consistency with Sec. 25.857, the FAA 
proposed that Sec. 25.858 would be amended to refer to ``smoke or fire 
detection provisions.'' That would place no additional burden on any 
person since the intent of Sec. 25.858 would remain unchanged.
    It was also noted that the term ``fire extinguishing system'' 
appearing in Sec. 25.857(c) in regard to Class C compartments is 
actually a misnomer in that the system is not required to extinguish a 
fire in its entirety, but rather to suppress it until it can be 
completely extinguished by ground personnel following a safe landing. 
Although the intent of the term is well-understood, consideration was 
given to replacing it with ``fire suppression system'' for technical 
accuracy. While the latter would be more accurate, it appeared that 
changing the terminology at this time could actually create confusion 
and, therefore, be counterproductive. The FAA, therefore, did not 
propose any change to Sec. 25.857(c) in that regard.
    Although the amendment to part 25 proposed in Notice 97-10 would 
provide new standards for future transport category airplanes, it would 
not affect airplanes currently in service nor the airplanes that will 
be produced under type certificates for which application was made 
prior to the effective date of the amendment. The FAA, therefore, 
proposed that parts 121 and 135 would be amended as well to require the 
Class D compartments of transport category airplanes type-certificated 
after January 1, 1958, to meet the standards for Class C or Class E 
compartments, as applicable, when they are used in air carrier or 
commercial operations. Although those compartments need not be 
reidentified as such, they would become the equivalent of Class C (in 
regard to detection and suppression) or Class E compartments (in regard 
to detection and means to limit ventilating air flow).
    The date January 1, 1958, was chosen so that all turbine-powered 
transport category airplanes, except for a few 1947 vintage Grumman 
Mallard amphibians and 1953-1958 vintage Convair 340s and 440s 
converted from reciprocating power, would be included. No 
reciprocating-powered transport category airplanes are known to be used 
currently in passenger service, and the few remaining in cargo service 
would be excluded. Compliance was not proposed for those older 
airplanes because their advanced age and small numbers would make 
compliance impractical from an economic standpoint. This is consistent 
with similar exclusions made for those airplanes from other retroactive 
requirements adopted for flammability of seat cushions (49 FR 43188, 
October 24, 1984), flammability of cabin interior components (51 FR 
26206, July 21, 1986), cargo or baggage compartments liners (54 FR 
7384, February 17, 1989) and access to passenger emergency exits (57 FR 
19244, May 4, 1992). Nevertheless, the FAA specifically requested 
comments as to the feasibility of requiring those older airplanes to 
comply and the safety benefits likely to be realized. The FAA noted 
that it retained the option of including applicability in the final 
rule to transport category airplanes type-certificated prior to January 
1, 1958, in the event comments indicate that a significant safety 
benefit could be realized.
    As proposed in Notice 97-10, the changes to parts 121 and 135 
concerning Class D compartments would require compliance within three 
years after the effective date of the amendment. It was noted that 
Class D compartment in passenger-carrying airplanes would be required 
to comply with existing standards for Class C compartments. Since the 
rulemaking would not involve any new technology and installation 
components are readily available, compliance within three years was 
considered feasible. A three-year compliance period would also allow 
sufficient time for the necessary modifications to be performed while 
each airplane is out of service for scheduled maintenance activity.

[[Page 8036]]

    As noted above, the compartments in all-cargo airplanes could be 
shown to meet the standards of Class E compartments in lieu of those 
for Class C compartments. The proposed three-year compliance period was 
also considered appropriate for operators that elect to meet the 
standards for Class E compartments. As in the case of Class C 
compartment standards, the standards for Class E compartments do not 
involve any new technology and installation components are readily 
available.
    Although the FAA considered that a three-year compliance period 
would not impose an unreasonable burden on any operator, based on 
available information, the FAA specifically requested comments as to 
whether a longer compliance period would be needed for particular 
operators (for example, small carriers) due to their particular 
circumstances. The FAA noted that it would retain the option of 
adopting a longer compliance period in the final rule based on such 
comments.
    The FAA also noted that it intends to monitor operators' 
compliance. Such monitoring would serve two purposes. First, it would 
help to ensure that the carriers are converting affected compartments 
on a regular basis, so as to avoid disruptions in service, and to avoid 
requests for extensions near the end of the compliance period. Second, 
the FAA could inform the public of the operators' progress in achieving 
compliance. The FAA, therefore, proposed specific reporting 
requirements for affected operators under parts 121 and 135. As 
proposed, a new paragraph would be added to Secs. 121.314 and 135.169 
to require each certificate holder to report, on a quarterly basis, the 
serial numbers of the airplanes in that holder's fleet in which all 
Class D compartments have been retrofitted to meet Class C or E 
requirements, and the serial numbers of airplanes that have Class D 
compartments yet to be retrofitted.
    The FAA intends to make the reported information publicly 
available, thus allowing the public to monitor the carriers' compliance 
progress. As required by the Paperwork Reduction Act, the Office of 
Management and Budget (OMB) has granted approval for the proposed 
reporting requirements. The assigned information collection control 
number, 2120-0614 will be listed in part 11, subpart F, of Title 14. 
This OMB approval expires August 31, 2000.
    The FAA also requested comments on what effects, if any, mandatory 
public disclosure requirements would have on the behavior of operators 
and others, given that the FAA intends to collect and make the 
information publicly available. For example would disclosure of the 
reported information result in compliance with retrofit requirements 
sooner than would otherwise be the case? If so, what effect would this 
have on the total amount and timing of benefits and costs of the rule? 
Also, what would be the best way to collect and make the information 
available, in order to enhance its usefulness to the public?
    As noted above, the new standards adopted in parts 121 and 135 for 
liners in Class C and D compartments are similar, but not identical, to 
those adopted for part 25. Section 25.855(c), as amended by Amendment 
25-60, states that ceiling and sidewall liner panels in such 
compartments must meet the test requirements of Part III of Appendix F 
of part 25. At the time the corresponding standards of parts 121 and 
135 were adopted, it was found that panels of glass fiber reinforced 
resin consistently meet or come very close to meeting the test 
requirements of Part III of Appendix F. As a result, the cost of 
replacing them with panels meeting Part III of Appendix F would not 
have been commensurate with the negligible improvement in safety that 
could be realized. Section 121.314(a) therefore permits the ceiling and 
sidewall panels to be constructed of materials that meet the test 
requirements of Part III of Appendix F or, alternatively, of glass 
fiber reinforced resin. Similarly, it was also found that panels of 
aluminum construction came close to meeting the test requirements of 
Part III of Appendix F, although not as close as those constructed of 
glass fiber reinforced resin. Section 121.314(a) therefore permits 
continued use of ceiling and sidewall panels constructed of aluminum 
provided they were approved prior to March 20, 1989. Since the FAA did 
not propose any change in this regard, Class D compartments that are 
reconfigured to the equivalent of Class C compartments could continue 
to utilize glass fiber reinforced resin panels or, if they were 
approved prior to March 20, 1989, aluminum panels in lieu of those 
meeting the test requirements of Part III of Appendix F.
    Due to the recent adoption of part 119 and related amendments to 
part 121 (60 FR 65832, December 29, 1995), scheduled operations of 
propeller-driven transport category airplanes with ten to thirty 
passenger seats and all turbojet-powered airplanes, regardless of their 
seating capacity, must be conducted under the provisions of part 121 
rather than part 135. Nevertheless, changes to part 135 were proposed 
because non-scheduled operations of transport category airplanes with 
ten or thirty passenger seats may still be conducted under part 135. 
Scheduled, as well as non-scheduled, operations of propeller-driven 
airplanes with fewer than ten passenger seats may also remain under 
part 135; however, none of these are transport category.

Halon Considerations

    As proposed in Notice 97-10, most Class D compartments would, in 
essence, become Class C compartments. Operators of all-cargo airplanes 
would have the option of converting their Class D compartments to Class 
E compartments; however, operators of passenger airplanes would have to 
convert their Class D compartments to meet the requirements of Class C. 
Although they were not previously required to have any means of fire 
extinguishment, the Class D compartments in passenger airplanes would 
have to have approved built-in fire extinguishing (or suppression) 
systems installed as required by Sec. 25.857(c)(2). Currently the most 
effective and most commonly used suppression agent is a halogenated 
hydrocarbon known as halon.
    Although reserve supplies of halon are currently available, the 
manufacture of additional halon is restricted under the Montreal 
Protocol, an international agreement to phase out production of ozone-
depleting substances, including halon. The Montreal Protocol, in 
existence since 1987, prohibits the manufacture or import of new halon 
in all developed countries (including the United States) as of January 
1, 1994, and will extend this prohibition to developing countries in 
the future. At this time, there is no restriction on the use of 
existing supplies of halon manufactured prior to 1994.
    Prior to the issuance of Notice 97-10, some operators expressed 
concern that they would be required to install suppression systems 
which would, as a matter of practicality, utilize halon, then be 
required by the FAA or another government agency to replace those 
suppression systems with systems that do not utilize halon. The FAA 
would not do so for two reasons. First, halon has been shown to be an 
effective suppression agent. The FAA would, therefore, not require its 
replacement due to safety considerations. Second, the FAA would not 
require its replacement due to environmental considerations because the 
FAA lacks the statutory authority to do so in any event. The federal 
agency that would have that authority is the Environmental Protection 
Agency (EPA).

[[Page 8037]]

    The EPA is responsible for the regulation of halons in accordance 
with the Montreal Protocol and the requirements and authority of 
Sections 602 and 604 of Title VI of the Clean Air Act. The EPA has 
advised in its letter of May 8, 1997, that it does not intend to ban 
the use of halon in installed fire suppression systems for the life of 
the airplanes, that it can support the use of stockpiled halons to 
retrofit aircraft cargo holds, and that it can support these policies 
in international negotiations related to aircraft or environmental 
matters. A copy of this letter was placed in the docket for examination 
by interested persons. Nevertheless, the EPA support for this 
rulemaking program is conditional on airline and aircraft industry 
support of on-going efforts to develop suitable alternatives for use in 
future aircraft, and on FAA's accelerated efforts to develop criteria 
for certification of alternatives, as described more fully below.
    In this regard, the FAA has participated in an extensive program to 
develop criteria on which to evaluate possible alternatives. Although 
initially proposed by the FAA, this is an international program with 
active participation by the aviation industry and the regulatory 
authorities in Europe and Canada. It must be emphasized that the work 
of this group, which is known as the International Halon Replacement 
Working Group, is to participate in the research and development of 
alternative agents and systems--not to select specific agents to 
replace halons. The FAA has accelerated development of criteria for 
certification of alternatives and is committed to expeditious review 
and certification of alternatives as they are developed.
    The objective of this program is to develop certification criteria 
for approval of alternative agents and systems. Such alternatives must, 
of course, have satisfactory environmental characteristics, such as 
reduced ozone depletion potential, global warming potential and 
atmospheric lifetime. In order to maintain the excellent record of in-
flight fire safety that exists today, new agents and systems must 
provide extinguishing and suppression performance equal to or better 
than the halons. In this regard, the development of minimum performance 
standards for alternative agents and systems in cargo or baggage 
compartments has focused on four critical threats--cargo container 
fires, bulk-loaded luggage fires, surface-burning fires and fires in 
luggage containing aerosol cans.
    In addition to performing their intended function of suppressing or 
extinguishing fires and having satisfactory environmental 
characteristics, alternative agents and systems used in airplanes must 
have certain other characteristics that may not be significant for non-
aircraft usage. They, of course, must not present a health hazard 
during normal operations to persons working within the compartments or 
animals being shipped in the compartments. Due to the proximity of the 
occupants of airplanes to the cargo or baggage compartments, the 
cumulative toxicology effect of the agents, their pyrolytic breakdown 
products and the by-products of combustion must not pose an 
unacceptable health hazard if a fire does occur. They must be non-
corrosive and otherwise compatible with aircraft materials. Discharge 
of the agent must leave a minimum of residue that can be safely cleaned 
up. Finally, such alternative agents and systems must be relatively low 
in weight for economical use in airplanes.
    One very promising alternative is the use of a waterspray system. 
The FAA has conducted a very comprehensive program to develop cabin 
waterspray systems as a means of affording occupants more time to 
escape a post-crash cabin fire. Although a waterspray system serving 
only the cabin has not been found to be cost-effective, it appears that 
benefits of a waterspray system that could also serve as the 
extinguishing agent in a cargo or baggage compartment fire may outweigh 
the costs of the system.
    Since the future availability of halon is uncertain, the FAA 
specifically invited comments concerning the following:
    1. The cost, feasibility and availability of halon for use as the 
suppression agent in former Class D compartments that would be 
reconfigured to meet the requirements of Class C as a result of this 
proposed rulemaking;
    2. The cost, feasibility and availability of waterspray systems 
that could provide protection from fires occurring in cargo or baggage 
compartments as well as in the cabin, and;
    3. The cost, feasibility and availability of other possible 
alternative agents.

Discussion of Comments

    More than 100 commenters responded to the invitation extended in 
Notice 97-10. The commenters included individuals, operators and 
manufacturers of affected airplanes, foreign airworthiness authorities, 
labor organizations, organizations representing aircraft manufacturers 
and operators, and the National Transportation Safety Board (NTSB).
    The NTSB strongly supports the proposal to convert Class D 
compartments to Class C in passenger airplanes and to convert Class D 
compartments to Class E compartments in all-cargo airplanes and 
believes that the FAA should expedite final rulemaking in that regard.
    Transport Canada also concurs with and fully supports the proposed 
rulemaking. The Civil Aviation Authority (CAA) of Great Britain fully 
supports the proposed rulemaking and proposes that parallel action be 
taken for equivalent airplanes registered in Joint Aviation Authorities 
(JAA) member countries. Although none are mentioned specifically, the 
CAA comment suggests that its data base may include relevant 
occurrences in addition to those mentioned in the preamble to Notice 
97-10.
    The National Association of Fire Marshals supports increased fire 
detection and suppression aboard airplanes and concurs with the FAA's 
assessment that detection alone does little to increase passenger 
safety when the airplane is airborne. The commenter opposes the 
introduction of halon suppression systems in airplanes, and recommends 
that the next 18 months be used to dramatically accelerate the process 
of approving halon alternatives. While the FAA fully supports the 
development of halon alternatives, that process is already being 
pursued as expeditiously as possible.
    The FAA noted in the preamble to Notice 97-10 that one promising 
alternative to halon is the use of a waterspray system. Several 
commenters express strong support for the further development of 
waterspray systems, while others adamantly oppose even mentioning it. 
As suggested by the latter, further research is needed before it can be 
verified that waterspray systems are indeed viable means of suppressing 
cargo compartment fires. Also, their cost effectiveness has not been 
fully established. Nevertheless, waterspray systems are promising. 
Consistent with their promising--but not yet proven--status, the final 
rule neither requires nor prohibits the use of waterspray systems as a 
means of compliance.
    One commenter submitted a videotape of testing conducted by a 
manufacturer of a combined halon and dry powder extinguishing agent. 
While interesting, the videotape promotes the manufacturer's product 
for home, stable and office use and did not directly address aircraft 
requirements. It, therefore, is not directly relevant to Notice 97-10.

[[Page 8038]]

    The FAA also invited comments concerning the cost, feasibility and 
availability of halon or possible alternative agents. Except for the 
comments noted above concerning waterspray systems, none of the 
commenters provided any specific information in those regards.
    Environment Australia expresses an understanding that the 
rulemaking proposed in Notice 97-10 would require the installation of 
halon 1301 suppression systems and draws the FAA's attention to four 
specific issues: the impact of increased emissions of halon 1301 from 
the installation of additional halon systems, the need to investigate 
and evaluate alternative agents for protection of unoccupied baggage 
compartments, potential problems in obtaining a supply of halon 1301, 
and possible ramifications of inconsistent national approaches. The 
commenter makes no specific recommendation concerning any of the above 
issues.
    Contrary to the commenter's understanding, the current standards 
for Class C compartments, which would be applicable to compartments 
presently classed as D compartments, are written in an objective sense, 
without specifying the means of obtaining the objective, so that 
suitable replacement agents could be used in lieu of halon. 
Nevertheless, each issue raised by the commenter was carefully 
considered in the preparation of Notice 97-10 and discussed in the 
preamble to that document.
    As discussed in the preamble to Notice 97-10, the Environmental 
Protection Agency (EPA) advised in its letter of May 8, 1997, that it 
does not intend to ban the use of halon in installed fire suppression 
systems for the life of the airplanes, that it can support the use of 
stockpiled halons to retrofit cargo compartments, and that it can 
support these policies in international negotiations related to 
aircraft or environmental matters. One commenter requested that EPA's 
commitment in this regard be incorporated in the final rule. The final 
rule is consistent with the EPA's commitment; however, it would be 
inappropriate and of doubtful legal effect for the FAA to commit 
another regulatory agency to any course of regulatory action in FAA 
rulemaking.
    One commenter recommends that the final rule be harmonized with the 
corresponding regulations of the European Joint Airworthiness 
Authorities (JAA). The JAA is an organization whose membership consists 
of the airworthiness authorities of various European countries. In 
order to standardize and greatly simplify type certification of 
aircraft, JAA has adopted a common code for type certification of 
transport category airplanes known as Joint Aviation Requirements-25 
(JAR-25). JAR-25 is patterned on, and is generally similar to, 14 CFR 
part 25. The JAA has also adopted other codes corresponding to other 
parts of the FAR. Although the JAA and FAA counterparts are generally 
similar, there are differences in certain areas. (The JAR-25 provisions 
relating to Class C, D and E compartments are the same as the part 25 
provisions as they existed prior to this amendment.) The FAA and the 
European airworthiness authorities are working together to minimize 
those differences to the greatest extent possible. This includes 
adopting new standards that are common to both FAA and JAA codes as 
well as harmonizing existing differences. In this particular instance, 
however, the FAA considered that the importance of obtaining the safety 
benefits of this rule outweighed the general policy in favor of 
harmonization. Nevertheless, as noted above, both the Civil Aviation 
Authority (CAA) of Great Britain, a prominent member of the JAA, and 
Transport Canada fully support the rulemaking proposed in Notice 97-10 
and suggest that they may pursue similar changes to their respective 
airworthiness codes.
    In a somewhat similar vein, one commenter notes that the proposed 
rulemaking would apply only to part 121 and 135 operators and requests 
that FAA make the proposed rules equally applicable to foreign as well 
as domestic operators. While the FAA appreciates the competitive 
considerations involved, any requirement for foreign airlines to meet 
these standards would be dealt with more appropriately by the 
airworthiness authorities of their country of registry. In any event, 
the imposition of such requirements on foreign airlines would be beyond 
the scope of Notice 97-10.
    The Regional Airline Association (RAA) concurs with the proposed 
requirement for retroactive installation of fire or smoke detection 
systems, but believes that extinguishing (or suppression) systems 
should be required only in compartments with volumes greater than 325 
cubic feet. In support of that position, the RAA expresses an 
assumption that, in referring to ``ATA (Air Transport Association of 
America) airplanes'' and ``non-ATA airplanes,'' the FAA is making a 
distinction between the larger transport category airplanes that ATA 
members typically operate and the small transport-category airplanes 
that RAA members typically operate. As discussed in Notice 97-10, ATA 
members agreed to install detection and suppression equipment 
voluntarily. The reference to non-ATA airplanes simply identifies those 
airplanes which are not subject to the ATA agreement. It is not related 
to the size of the airplane involved.
    In support of its belief that suppression systems are not needed, 
RAA makes the erroneous assertion that most fires have occurred during 
takeoff when certain articles in a cargo or baggage compartment have 
become dislodged. Contrary to the RAA's assertion, most of the fires or 
cargo or baggage compartments occurred after the airplane became 
airborne.
    The RAA also questions why the cost-benefit analysis would include 
Class C compartment fires when the proposed rule affects only Class D 
compartment fires. As noted in the preamble to Notice 97-10, the 
consequences of a fire depend greatly on the fire-protection features 
of the compartment in which it occurs. The probability that an ignition 
will occur, however, is primarily a function of the flammability of the 
material being carried in the compartment and the sources of ignition. 
Service experience with Class C compartments is, therefore, equally 
relevant insofar as the probability that a fire will occur is 
concerned. The RAA is correct in noting that the adverse experience 
with Class D compartments to date has been with larger compartments; 
however, the recent substitution of highly flammable propellants in 
consumer aerosol cans has introduced a new hazard that did not exist 
previously.
    The RAA believes that the tests conducted by the FAA with aerosol 
cans were not representative of conditions that could be encountered in 
a small Class D compartment. In that regard the RAA does not believe 
that a fire of sufficient intensity to cause an aerosol can to explode 
could occur in smaller Class D compartments. Contrary to the RAA's 
understanding of the mechanism of the explosion, the fire only has to 
be of sufficient intensity to cause the aerosol can to burst from over 
pressure. When an aerosol can bursts in a non-inert atmosphere, such as 
that in a Class D compartment, it is likely to explode.
    The RAA also believes that it is unrealistic to imagine that the 
resulting explosion could rupture not only the compartment liner, but 
also the surrounding aircraft structure. As discussed in Notice 97-10, 
tests have shown that an explosion of an aerosol can is of such force 
and intensity that the liner could be rendered ineffective in limiting 
the supply of oxygen to the fire. With an unlimited supply of

[[Page 8039]]

oxygen and the integrity of the liner compromised, there is no longer 
an effective means to prevent an uncontrollable fire from spreading to 
other parts of the airplane regardless of whether the surrounding 
structure of the airplane is ruptured. Notice 97-10 was intended to 
address this risk of uncontrollable fire rather than problems resulting 
from damage to surrounding structure. Regarding such damage, however, 
the FAA did conduct additional testing subsequent to the issuance of 
the notice, using a simulated aerosol can and a portion of the fuselage 
of a Boeing Model 727. The explosion experience in that test was of 
sufficient force to rupture not only the liner, but the end of the 
compartment and the cabin floor structure above the compartment as 
well. The structure of airplanes used by regional airlines would be no 
more resistant to such damage than 727 structure. A copy of Technical 
Note No. AR-TN97/103, entitled ``Development of an Exploding Aerosol 
Can Simulator,'' describing that test and a videotape of the test have 
been added to the docket for this final rule.
    The RAA notes that the FAA requires the retroactive installation of 
improved cargo compartment liners (Amendments 121-202 and 135-31, 54 FR 
7384, February 17, 1989) only on Class C and D compartments larger than 
200 cubic feet and believes that is inconsistent with the proposed 
requirement to install detection and suppression in all Class D 
compartments regardless of size. As discussed earlier, part 25 was 
amended to require all new installations of Class C or Class D 
compartments to meet the new liner standards regardless of size. Parts 
121 and 135, on the other hand, require only compartments greater than 
200 cubic feet to have liners that meet the new liner standards.
    As discussed in Notice 97-10, the primary purpose of the liners is 
to withstand penetration by flames and thereby prevent the fire from 
spreading from the cargo or baggage compartment to other parts of the 
airplane. Retroactive compliance with the newer liner standards of 
Amendments 121-202 and 135-31 is not required for smaller compartments 
because the safety benefits that could be realized were not considered 
sufficient to justify the costs of replacing their liners. This 
conclusion was based on the fact that the effect of the newer liner 
standards was to provide an incremental increase in the ability of 
cargo compartments to contain fires. Because compartments smaller than 
200 cubic feet contain relatively less oxygen to sustain a fire, the 
improvement in containment for these compartments was not considered 
sufficient to warrant their replacement.
    In addition to its argument that no suppression is required for 
compartments smaller than 325 cubic feet, the RAA suggests that it may 
not be necessary, in relatively small airplane compartments, to provide 
both an initial ``knockdown'' discharge and the capability to maintain 
a 3 percent halon concentration for one hour. In RAA's view, a 
suppression system that simply knocks down the fire should be 
considered adequate for certain compartments that do not contain 
sufficient oxygen for a fire to continue.
    The reference to a 3 percent concentration quoted by the RAA is 
actually contained in the Regulatory Evaluation Summary of Notice 97-10 
and is the amount of halon that is typically used, not an amount that 
is required. The standards for Class C compartments, which the current 
Class D compartments in passenger-carrying airplanes would have to 
meet, neither specify the agent that must be used nor the specific 
concentration of agent that must be maintained. The agent, typically 
halon, and the concentrations expended must simply be sufficient to 
extinguish the fire altogether or suppress it until a safe landing can 
be made. It must be recognized, however, that a system that could not 
prevent a fire from growing back after initially suppressing it would 
not be acceptable.
    In contrast, this final rule has the effect of changing, from 
containment to suppression, the primary means of preventing 
uncontrolled fires in Class D compartments in passenger-carrying 
operations. Rather than resulting in an incremental improvement, this 
change is expected to make a decisive difference in preventing 
uncontrolled fires, particularly under two scenarios. First, when a 
fire is initiated as a result of improper carriage of hazardous 
materials, suppression is much more likely to be successful than 
containment alone. Second, with the widespread use of consumer aerosol 
cans with highly flammable propellants, containment is no longer the 
primary consideration. Although still extremely important in the 
overall fire safety of the compartment, the capability of the liners to 
withstand the penetration of flames is a secondary concern because the 
integrity of a liner can be destroyed by the force of an exploding 
aerosol can regardless of its capability to resist flame penetration. 
Apart from its erroneous beliefs that the proposed rulemaking is 
inconsistent with the earlier rulemaking and that most cargo or baggage 
compartment fires occurred during takeoff, the RAA offered no technical 
justification for excluding compartments smaller than 325 cubic feet.
    The FAA does acknowledge RAA's assertion that inadvertent carriage 
of oxygen generators aboard airplanes flown by RAA members is unlikely 
because their fleets typically consist of airplanes with oxygen-
containing cylinders rather than oxygen generators. It must be 
recognized, however, that oxygen generators are only one example of 
hazardous flammable materials that may be loaded in compartments 
inadvertently or surreptitiously. Also, patrons of regional airlines 
would be no less likely to have aerosol cans in their checked baggage 
than the patrons of major airlines.
    In view of the above, the FAA does not concur with the RAA's belief 
that compartments smaller than 325 cubic feet need not have fire 
suppression.
    At the time Notice 97-10 was drafted, it was believed that most 
smaller transport category airplanes designed for business use 
incorporate Class B compartments that are accessible in flight and that 
relatively few have Class D compartments. It was also believed that 
most of those airplanes are used for personal or executive use under 
the provisions of 14 CFR part 91. Since that time it has become 
apparent that a significant number do have Class D compartments located 
in the nose or tail section outside the cabin pressure vessel and that 
many are, in fact, used for on-demand service under the provisions of 
14 CFR part 135. Some airplanes originally designed for executive use 
have also been converted for all-cargo operations conducted under part 
135. Consequently many more of those airplanes would be affected by the 
proposed rulemaking than originally anticipated.
    As noted above, scheduled common-carriage operations of propeller-
driven airplanes with ten to thirty passenger seats and all turbojet-
powered airplanes, regardless of their seating capacity, must now be 
conducted under the provisions of part 121 rather than part 135. 
Scheduled common-carriage operations with propeller-driven airplanes 
having fewer than ten passenger seats may still be conducted under part 
135, but none of those airplanes are transport category. Accordingly, 
the proposed changes to part 135 would not apply to any airplane likely 
to be used in scheduled passenger operations.
    In regard to operations that may still be conducted under part 135, 
airplanes with 30 or fewer passenger seats and 7,500 pounds or less 
maximum payload may be used for non-scheduled, i.e. on-demand, common-
carriage operations.

[[Page 8040]]

Typically, such operations involve charter flights for transportation 
of company executives, entertainment groups, etc. The transport 
category turbojet-powered airplanes designed for business travel (as 
opposed to the few larger airliners flying as executive airplanes) fall 
within these seating and weight limits. As discussed above some of 
these airplanes are used for such operations, and some do have Class D 
compartments. Because of the seating and payload limits, the only 
extant propeller-driven transport-category airplanes with Class D 
compartments that would be eligible for such operations are CASA 
C.212's or Jetstream 4101's. No airplanes of either model are known to 
be so used.
    With passenger seats removed, transport category airplanes with 
7,500 pounds or less maximum payload are also eligible for all-cargo 
service.
    In addition to non-scheduled common carriage, airplanes with fewer 
than 20 passenger seats and 6,000 pounds or less payload are eligible 
for non-common or private carriage operations.
    The National Air Transportation Association (NATA), which 
represents operators of airplanes utilized for on-demand flights, 
recommends that airplanes operated under part 135 be excluded from the 
proposed rulemaking. The NATA asserts that on-demand carriers maintain 
close control of the contents of baggage placed in their Class D 
compartments. In that regard, the NATA believes that the carriage of 
consumer aerosol cans should be prohibited. The NATA notes that part 
135 operators do not transport other types of cargo, such as parcels 
being transported on behalf of customers other than those chartering 
the airplanes, tires and other aircraft parts.
    The NATA states that the Class D compartments in the airplanes used 
in part 135 service are no larger than 25 cubic feet and, like the RAA, 
believes that the FAA set a precedent in that regard by requiring the 
retroactive installation of improved cargo compartment liners only on 
Class C and D compartments larger than 200 cubic feet. Raytheon, a 
manufacturer of such airplanes, also recommends that compartments less 
than 200 cubic feet not be required to comply. As discussed above, the 
earlier exclusion of compartments smaller than 200 cubic feet is not 
relevant to the hazards addressed by this rulemaking.
    Approximately one dozen commenters, who identified themselves as 
part 135 operators, provided comments similar in nature to those of the 
NATA. The General Aviation Manufacturers Association (GAMA), which 
represents manufacturers of airplanes intended for business use, 
provides similar comments and suggests that such airplanes with maximum 
takeoff weights less than 75,000 pounds operated in non-scheduled 
flight under part 91 or part 135 be excluded from the rulemaking. (The 
FAA did not propose that any airplanes operated only under part 91 
would have to comply.) GAMA also notes that no uncontrolled fire has 
ever occurred in a Class D compartment in a business airplane.
    An operator engaged in all-cargo operations under the provisions of 
part 135 notes that it does not face the problem of flammables in 
passenger baggage (presumably referring to aerosol cans) and that the 
majority of cargo carried in such operations is bank documents. Bank 
documents are shipped in tightly compressed bundles which, according to 
the commenter, are not capable of spontaneous combustion.
    The commenter also notes that the airflow in Learjets, which are 
typically used for such service, is from the main cargo bay forward, so 
that the flightcrew would detect any unusual fumes or odors from the 
cargo in time to effectively fight with on board halon or make an 
emergency landing. The commenter is undoubtedly referring to airplanes 
in which the main cabin has been converted to a cargo compartment. 
While the comment may be correct, it is not relevant because the main 
cabins of those airplanes would not be Class D compartments. The Class 
D compartments of Learjets and other airplanes used for such service 
are the small isolated compartments located in the nose or tail of the 
airplanes.
    The FAA does not concur with the NATA suggestion that the carriage 
of aerosol cans should be prohibited in lieu of the proposed 
rulemaking. The use of consumer aerosol cans with highly flammable 
propellants is so widespread that it would be impossible to enforce a 
prohibition of this nature in any type of aircraft operation regardless 
of how well an operator could maintain control of the contents of its 
customers' baggage.
    While no conclusive evidence has been presented, the commenters 
have raised issues worthy of further study to determine whether a 
significant safety benefit could be realized by requiring all transport 
category airplanes operated under part 135 to comply. In order to 
preclude delaying compliance of the airplanes flown by the mainstream 
part 121 operators, the FAA has elected to delay rulemaking pertaining 
to part 135 operators for further study. In order to assess the 
possible safety benefits and costs more accurately, the FAA is 
requesting further comments concerning the types of operations 
conducted under part 135. (See Request for Comments below.) Following 
completion of the further study, the FAA will take one of the following 
three actions: (1) If the FAA determines that the proposed requirements 
are necessary for safety and cost effective for all part 135 operators, 
part 135 will be amended as proposed in Notice 97-10 to require all 
operators of transport category airplanes with Class D compartments to 
comply. (2) If the FAA determines that the proposed requirements are 
necessary for safety and cost effective only for some types of part 135 
operators, part 135 will be amended to require compliance by those 
operators. (3) If the FAA concludes that the proposed requirements are 
not necessary for safety and cost effective for part 135 operators 
generally, the proposal to amend part 135 will be withdrawn.
    Forty-eight individuals, most of whom identified themselves as 
pilots for a major all-cargo airline, and a labor organization 
representing those pilots submitted similarly-worded comments opposing 
the continued use of Class E compartments. The commenters quote the 
statement, ``In the case of all-cargo airplanes, the expected life 
saving benefit is assumed to be zero,'' and construe it to mean that 
the FAA does not value the lives of crew members of all-cargo 
airplanes. On the contrary, that statement, which appeared in the 
Benefits Estimates section of the preamble to Notice 97-10, merely 
reflects a conservative assumption made in calculating the estimated 
total benefits that would likely result for all airplanes, passenger 
and cargo, from the proposed rulemaking. It is not the basis for any 
action taken or not taken, and it does not, in any way, reflect a lack 
of concern for the safety of occupants of all-cargo airplanes. In that 
regard, it must be recognized that this final rule requires a higher 
level of safety for all-cargo airplanes by requiring the Class D 
compartments in those airplanes to meet the superior standards for 
either Class C or Class E compartments.
    Those commenters, and three other labor organizations, assert that 
the rulemaking must eliminate Class E as well as Class D compartments 
as an option. Some cite a recent accident in which an all-cargo Douglas 
DC-10 was destroyed by a fire originating in a Class E compartment. As 
discussed above, Class E compartments are, like Class C compartments, 
required to have smoke or fire detection systems; however, means must 
be provided to shut off the flow of ventilating air to or within a

[[Page 8041]]

Class E compartment, in lieu of providing extinguishment. In addition, 
procedures, such as depressurizing a pressurized airplane, are 
specified in order to minimize the amount of oxygen available in the 
event a fire occurs in a Class E compartment. Class E compartments can 
be installed only in all-cargo airplanes since these procedures are 
generally not feasible in passenger-carrying airplanes.
    The accident to which the commenters refer is undoubtedly that 
which occurred on September 5, 1996. According to the National 
Transportation Safety Board (NTSB), the crew made an emergency landing 
at New Windsor, New York, following activation of the cargo compartment 
smoke detectors. Although cited by the commenters as an indication that 
Class E compartments are unsafe, the smoke detectors provided warning 
that a fire had occurred; and the crew was able to land and safely 
evacuate the airplane approximately one hour before it was destroyed by 
the fire. The NTSB did not issue any safety recommendations as a result 
of this accident.
    Adopting a final rule that would eliminate Class E compartments as 
well as Class D compartments would be beyond the scope of Notice 97-10, 
in any event, but service experience does not show that Class E 
compartments are unsafe as claimed by the commenters.
    As proposed in Notice 97-10, part 121 would be amended to require 
the Class D compartments of transport category airplanes type-
certificated after January 1, 1958, to meet the standards for Class C 
or Class E compartments, as applicable. That date was chosen so that 
all turbine-powered transport category airplanes, except for a few 1947 
vintage Grumman Mallards and 1953-1958 vintage Convair 340s and 440s 
converted from reciprocating power, would be included, Compliance was 
not proposed for the older airplanes because their advanced age and 
small number would make compliance impractical from an economic 
standpoint. Nevertheless, the FAA specifically invited comments in that 
regard and retained the option of including applicability to the older 
transport category airplanes in the final rule if comments indicate a 
significant safety benefit could be realized thereby. Several 
commenters support the exclusion of those older airplanes. No comments 
were received opposing the exclusion; however, two commenters request 
that the date be adjusted to exclude Lockheed 188 Electras, which were 
type-certificated on August 2, 1958--seven months later than the 
proposed date.
    One commenter uses its three Electras for service to certain remote 
Aleutian points that cannot be served safely with jet aircraft. Those 
airplanes plus one Electra flown by the other commenter on military 
contract flights are the only passenger-configured Electras in service 
in this country. Because of their small numbers, the manufacturer of 
those airplanes has chosen not to provide engineering support for the 
installation of detection and suppression systems. The commenter states 
that installing fire suppression systems on its three Electras would, 
therefore, present an excessive economic burden. Apart from the four 
passenger-configured Electras, there are approximately two dozen all-
cargo configured Electras in service in the U.S.
    In addition to the passenger-configured Electra flown on military 
contract flights and an all-cargo Electra, the other commenter also 
operates ten Convair 340s and 440s. That operator requests that an 
exclusion be made for the Convairs as well as Electras. Since the 
Convair airplanes were type-certificated well before January 1, 1958, 
that comment is interpreted to be support for the exclusion already 
proposed in Notice 97-10 for the older airplanes.
    The FAA does not consider the information presented by the 
commenters sufficient to warrant a general exclusion of Electras from 
compliance--particularly in the absence of comments from other Electra 
operators opposing the January 1, 1958, date. Because the two 
commenters' concerns relate to circumstances peculiar to their 
operations, the appropriate process for considering those circumstances 
is a petition for exemption filed under the provisions of 14 CFR part 
11. That process would entail a showing by the petitioner that the 
requested relief is in the public interest. The date January 1, 1958, 
is, therefore, adopted as proposed.
    Three commenters, the RAA, a manufacturer of airline airplanes and 
an all-cargo airline, oppose the reporting provisions proposed in 
Notice 97-10. The RAA quotes the probable event rate of 0.085 cargo 
compartment fires per million departures stated in the Benefits 
Estimates section of the preamble to Notice 97-10 and characterizes the 
probability of one becoming injured as a result of a fire in an 
airplane operated by a regional carrier as an extremely remote event. 
The RAA believes that the reporting requirement would mislead the 
public into believing that airplanes that do not have detection and 
suppression systems installed pose a safety risk unwarranted by the 
probable event rate.
    The manufacturer characterizes the proposed quarterly reporting 
requirement as unnecessary bureaucracy. That commenter further states 
that it is the FAA's responsibility to regulate operators and 
characterizes publishing information concerning persons that have not 
met the rule before being required to do so as invidious and of 
doubtful legality.
    Two commenters do not particularly oppose the proposed reporting 
requirement, but nevertheless offer constructive suggestions. One 
suggests that care must be taken to present the information to the 
public in such a manner that it is not misleading. For example, one 
carrier's entire fleet may have Class D compartments while another's 
fleet might consist largely of airplanes that have no such 
compartments. The latter's progress (or lack of progress) in fleet 
compliance would be much less significant in terms of overall fleet 
safety than the former's progress. The other commenter suggests that 
Sec. 121.314 specifically state that the reporting requirement is 
discontinued once the carrier has completed the conversion of its 
entire fleet.
    The FAA does not consider that the dissenting commenters have 
provided persuasive reasons to delete the proposed reporting 
requirement from the final rule. In that regard, the FAA considers that 
the public has a strong interest in knowing how aggressively operators 
are acting to provide the safety benefits of compliance with this rule. 
Concurrence with this position is reflected in approval for the 
reporting requirement granted by the Office of Management and Budget. 
The FAA does, however, concur that the results of the required 
reporting must be presented to the public in a manner that is not 
misleading. It was understood, but not specifically stated in proposed 
Sec. 121.314(d), that the reporting requirement would apply only until 
the carrier's entire fleet is converted. In order to preclude any 
confusion in that regard, the second sentence of paragraph (d) is 
changed to read, ``Until such time as the certificate holder's entire 
fleet is in compliance, each certificate holder must * * *.''
    In addition, the reporting requirement has been revised to refer to 
airplanes in which all Class D compartments have been converted to 
Class C or Class E (i.e., those reidentified as such), or retrofitted 
to meet the applicable requirements of Class C or Class E. As explained 
elsewhere in this preamble, a Class D compartment that is converted to 
a Class C compartment (and

[[Page 8042]]

reidentified as a Class C compartment) prior to the three-year 
compliance date is, literally, not a Class D on that date; the airplane 
with that compartment would not be reported under the literal language 
of the proposal. However, the agency is clarifying that each airplane 
that has Class D compartments converted in such a manner should be 
reported in the same manner as an airplane on which all class D 
compartments have been retrofitted with the requisite detection or 
detection and suppression systems. This clarification is consistent 
with the commenters' apparent understanding of the proposal.
    Several commenters express their belief that compliance should be 
required in less than three years, as proposed. A three-year compliance 
period was proposed because, according to information available to the 
FAA, a shorter period would not enable operators to perform the 
necessary modifications while their airplanes are undergoing other 
scheduled maintenance. Having to remove airplanes from service earlier 
specifically to perform the modifications required by this final rule 
would increase the cost of compliance to the point that the final rule 
would no longer be cost effective. In addition, it appears doubtful 
whether parts and materials would be available to enable compliance of 
all affected airplanes within a shorter compliance period. The FAA, 
therefore, does not concur that a compliance period shorter than three 
years would be appropriate. In any event, commenters have not been 
specifically asked to focus on the effects of imposing a shorter 
compliance period. In fact, as discussed below, most operators appear 
to believe that a compliance period longer than three years is 
warranted. Under the current circumstances, therefore, the FAA would 
not want to adopt a shorter compliance period without publishing a 
notice for additional comments. The additional notice, in turn, would 
result in a delay that would be counterproductive.
    In contrast to the commenters that believe a compliance period 
earlier than three years should be adopted, several commenters believe 
that a longer period should be adopted. The Air Transport Association 
of America (ATA) and the Aerospace Industries Association (AIA), which 
represent airlines and manufacturers of airline airplanes, 
respectively, request that the compliance period should be five years. 
This request is based primarily on the commenters' assertions that a 
compliance period of less than five years would not enable compliance 
while the airplanes are undergoing other scheduled maintenance. The RAA 
requests that it be four years, but provides no specific justification 
for its request. The FAA has carefully evaluated the assertions made by 
the ATA and AIA and other available information concerning compliance. 
In that regard, it must be noted that the changes proposed in Notice 
97-10 do not require the use of new technology. Future compartments 
that could no longer be Class D, and existing Class D compartments, 
must meet the standards for either Class C or Class E, as applicable. 
Those standards have been in existence for 51 and 38 years, 
respectively; and many of the airplanes currently in the U.S. air 
carrier fleet already meet them. It is also noted that approval has 
already been granted for the installation of detection and suppression 
systems in some of the models that comprise most of the affected 
airplanes in the U.S. air carrier fleet. The FAA recognizes that a 
three-year compliance period, as proposed in Notice 97-10, would be 
aggressive and would require careful planning; however, none of the 
commenters have provided credible reasons suggesting that detection and 
suppression systems cannot be installed in all affected airplanes 
within three years while the airplanes are undergoing other scheduled 
maintenance. A three year compliance period is, therefore, adopted as 
proposed.
    The FAA noted in the preamble to Notice 97-10 that the term ``fire 
extinguishing system'' appearing in Sec. 25.857(c) in regard to Class C 
compartments is actually a misnomer in that the system is not required 
to extinguish a fire in its entirely. The system is intended, instead, 
to suppress a fire until it can be completely extinguished by ground 
personnel following a safe landing. The FAA also noted that 
consideration was given to replacing the term with ``fire suppression 
system'' for technical accuracy, but that no change was proposed 
because it appeared that changing the terminology at this time could 
actually create confusion and, therefore, be counter-productive. 
Several commenters suggest the term ``fire suppression system'' should 
indeed be used in order to preclude any misunderstanding. In light of 
the comments received, Sec. 25.857(c)(2) is changed to read ``fire 
extinguishing or suppression system.'' This is a nonsubstantive change 
that places no additional burden on any person.
    One commenter states that Sec. 121.314(c) should clearly state that 
an existing approved Class C compartment detection system meeting the 
earlier five-minute detection standard remains acceptable for 
conversion of existing Class D compartments. The suggested change to 
that section is unnecessary. As discussed under Background above, 
Sec. 25.858 was adopted in 1980 to require the detection systems of 
Class B, C and E compartments to provide visual indication to the 
flightcrew within one minute of the start of the fire. Prior to that 
time, systems that provided indication within five minutes were 
considered acceptable. This final rule does not require any changes to 
Class C compartments, including those that were approved previously 
when five-minute detection time was considered acceptable. In some 
instances, for example, a manufacturer offered a specific compartment 
in a specific airplane model as either a Class C or Class D compartment 
can convert that compartment to the previously-approved Class C 
compartment. By virtue of having been converted to a Class C 
compartment (and no longer a Class D compartment), Sec. 121.314(c) 
would no longer be applicable to the compartment.
    Therefore, whether it meets the older five-minute standard or the 
current one-minute standard would not be an issue in determining 
compliance with this section.
    There may be instances in which a specific airplane model 
incorporates one or more Class C compartments with detection systems 
meeting only the older five minute standard and one or more Class D 
compartments. The existence of a previously-approved detection system 
in another compartment would not be relevant to whether the system for 
a Class D compartment in that airplane had to meet the new one-minute 
standard.
    There may also be instances in which detection systems were 
installed in Class D compartments and not shown to meet any particular 
standard for detection (i.e., approved on the basis that they did not 
detract from the performance of the compartments as Class D 
compartments.) Those systems would have to be demonstrated to meet the 
current one-minute standard or replaced with systems that do.
    Similarly, there are instances in which the means of fire 
suppression in Class D compartments were approved on the basis that the 
systems did not detract from the performance of the compartments as 
Class D compartments. Such previously-approved systems must also meet 
the standards for fire suppression systems in Class C

[[Page 8043]]

compartments or be replaced with systems that do.
    The RAA, in its comments, references a system for inserting hand 
fire extinguishers into the compartments of Shorts SD3-60 and Jetstream 
4104 airplanes. The RAA states that the compartments with the hand fire 
extinguishing systems were originally approved as Class C compartments, 
but later reidentified as Class D compartments to accommodate dispatch 
reliability requirements. However, these compartments are not 
certificated as Class C compartments. Moreover, the certification of 
these compartments as Class D was not centered on the need to 
facilitate dispatch. Therefore, for these compartments to be 
certificated as Class C, the applicant must demonstrate that the built-
in suppression systems meet Class C requirements.
    Alternatively, an RAA member always has the option of petitioning 
for an exemption under the provisions of 14 CFR part 11. Under part 11, 
an interested person may petition the Administrator for a temporary or 
permanent exemption from any FAA rule. In a petition for exemption, the 
person seeking relief must include: (1) the text or substance of the 
rule from which the exemption is sought; (2) a statement of the 
petitioner's interest; specifically, the nature and extent of the 
relief sought and a description of the aircraft or person(s) to be 
covered by the exemption; and (3) arguments for granting such an 
exemption, focusing on the reasons why the proposed exemption is in the 
public interest and would not adversely affect, or would provide an 
equivalent level of, safety akin to the rule from which the exemption 
is being sought.
    In consideration a petition for exemption from the fire detection 
and suppression requirements, the FAA will evaluate whether the 
petitioner has demonstrated unique circumstances that make granting the 
proposed exemption in the public interest. Under 49 USC 40101(d), 
Congress requires the Agency, in making a public interest funding, to 
consider that ``assigning, maintaining and enhancing safety and 
security are the highest priorities in air commerce.'' Therefore, an 
RAA member would have an opportunity, for example, to demonstrate that 
the continued use of a hand extinguisher is functionally equivalent to 
an approved built-in fire extinguishing system or that some other 
unique circumstances justifies an exemption while avoiding an adverse 
effect on safety.
    Two commenters offer comments concerning dispatch reliability 
requirements. Others offer comments that actually deal with acceptable 
means of compliance rather than the rulemaking per se. Since the Class 
D compartments will become the equivalent of Class C or Class E 
compartments, they will be treated as such insofar as dispatch 
requirements are concerned. For the same reason, means that are 
presently acceptable for compliance with the standards for Class C or 
Class E compartments will remain applicable.
    One commenter expresses the concern that the chemical to suppress a 
fire could also deplete the amount of oxygen needed to support human 
life. While valid, that concern is addressed by the standards already 
contained in Sec. 25.851(a)(8) and (b)(1)(i).
    Other commenters suggest changes that would be beyond the scope of 
Notice 97-10, including such diverse subjects as incorporation of 
extinguishment systems in containers containing hazardous materials, 
access to and positioning of such containers, the use of detection 
systems that sense both heat and smoke, improved crew training 
procedures, increased crew oxygen supplies, and a re-evaluation of 
existing Class C compartments. While some of those suggestions might 
have merit, they would require considerable further study and could not 
be adopted at this time. Several commenters provide information of an 
economic nature which has been considered in the preparation of the 
regulatory evaluation for this final rule. Although one commenter 
expressed a concern related to a particular Alaskan intrastate 
operation involving Lockheed Electras, no commenters responded to the 
FAA's request for comments on whether there is sufficient justification 
for applying the proposed rule differently to intrastate operations in 
Alaska.
    Except as discussed above, parts 25 and 121 are amended as proposed 
in Notice 97-10. As also discussed above, no amendment is made to part 
135 pending receipt of additional information as requested below.

Request for Comments

    As a result of comments received, it appears that the impact of the 
proposed rulemaking on part 135 operators may be much greater than 
anticipated at the time Notice 97-10 was drafted. Also, it is not clear 
whether the proposed rulemaking would be cost beneficial for all such 
operators. In order to not delay the applicability of the proposed 
rulemaking to manufacturers and the other operators for which it has 
been found cost-beneficial, the FAA has elected to adopt this final 
rule amending parts 25 and 121 and defer the proposed changes to part 
135 pending receipt of additional information. The FAA, therefore, 
requests additional comments addressing the following specific 
questions:
    1. Which airplane models operated under part 135 have Class D 
compartments that were installed at the time of manufacture? Of these, 
which are used in all-cargo operations?
    2. Which airplane models operated under part 135 have been 
subsequently modified to incorporate Class D compartments? Of those, 
which are used in all-cargo operations?
    3. What are the sizes (by model) of the Class D compartments of 
airplanes operated under part 135?
    4. In the case of on-demand passenger flights, are Class D 
compartments ever used to transport items other than the baggage of the 
persons chartering the airplane? If so, what types of cargo or baggage 
are carried in these compartments, and how frequently are they carried?
    5. In the case of all-cargo flights, are the Class D compartments 
utilized? If so, what types of cargo or baggage are carried, and how 
frequently are they carried?
    6. In the case of operators that have approval to transport 
hazardous materials, are Class D compartments ever use to transport 
those materials?
    7. Do you have any knowledge of a fire occurring in a Class D 
compartment of an airplane operated under part 135? Was the fire safely 
contained in the compartment?
    8. Are there any existing FAA-approved installations of detection 
and suppression systems meeting the standards for Class C compartments 
in these compartments?
    9. For those Class D compartments for which there are no existing 
FAA-approved installations of detection and suppression systems, what 
would be the costs of designing and obtaining FAA approval of such 
systems?
    10. How much labor would be required to retrofit the Class D 
compartments with detection and suppression systems? Could these 
modifications be accomplished during regularly scheduled maintenance, 
or would the airplanes need to be taken out of service specifically for 
this purpose? If so, for how long?
    11. What would be the costs of materials and compartments needed to 
retrofit the Class D compartments with detection and suppression 
systems?
    12. If the FAA required part 135 operators to install detection and 
suppression systems in Class D compartments, would those operators 
modify those compartments

[[Page 8044]]

accordingly, or would they comply by simply deactivating those 
compartments and utilizing other compartments? Be model-specific for 
both passenger and cargo airplanes, if possible.
    13. What would be the economic consequences of deactivating a Class 
D compartment? Could operators utilize other compartments to continue 
to carry the same payloads if the Class D compartments are deactivated?
    Comments submitted to Docket Number 28937 no later than May 18, 
1998 will be considered. The FAA will review all additional comments 
relevant to the above questions and publish either a supplemental final 
rule presenting FAA findings and adopting any necessary changes to part 
135 or a notice stating the basis for its conclusion that no further 
changes are warranted.

Regulatory Evaluation Summary

    Proposed changes to Federal regulations must undergo several 
economic analyses. First, Executive Order 12866 directs that each 
Federal agency shall propose or adopt a regulation only upon reasoned 
determination that the benefits of the intended regulation justify its 
costs.
    Second, the Regulatory Flexibility Act of 1980 requires agencies to 
analyze the economic effect of regulatory changes on small entities. 
Third, the Office of Management and Budget directs agencies to assess 
the effects of regulatory changes on international trade. In conducting 
these analyses, the FAA has determined that this rule: (1) will 
generate benefits that justify its costs and is a ``significant 
regulatory action'' as defined by Executive Order 12866; (2) will have 
a significant impact on a substantial number of small entities; and (3) 
will not constitute a barrier to international trade. The FAA has also 
determined that this rule is ``significant'' according to DOT 
Regulatory Policies and Procedures (44 FR 11034; February 26, 1979) 
because there has been considerable public interest in this subject. 
These analyses, available in the docket, are summarized below.

Discussion of Comments Related to the Economic Analysis

    Comments related to the economic analysis can be grouped as 
follows: (1) comments addressing specific benefit or cost assumptions, 
(2) comments recommending a reduction in the compliance time, (3) 
comments requesting an increase in the compliance time, (4) comments 
calling for the expansion of detection and suppression requirements, 
(5) comments requesting that some operations be excepted from detection 
and suppression requirements. The last four groups of comments are 
addressed elsewhere in the preamble. What follows is a discussion of 
comments specifically addressing the economic assumptions.
    At least one commenter raised questions regarding the inclusion of 
non-domestic aviation incidents, such as the Gulf Air and Saudi Arabian 
incidents, for purposes of developing a quantified estimate of the 
benefits of the rule. The FAA believes that it is reasonable to include 
the Gulf Air and Saudi Arabian incidents in the calculation of 
quantified benefits. Some may argue that these incidents are not 
pertinent. However, a careful examination of these accidents by FAA 
security and other safety experts concluded that nothing about the 
causes of those accidents could be classified as risks that are 
inherently different from U.S. risks. Thus, the FAA believes that the 
circumstances that caused both the fires and the deaths could occur in 
U.S. operations. Another alternative analysis just relying on domestic 
incidents could also have been done. If the two foreign accidents were 
not counted, of course, the total benefits quantified in the Regulatory 
Evaluation for this rule might be lower. However, the FAA believes 
that, even without considering the foreign accidents, the quantified 
and non-quantifiable benefits (such as the potential for increased 
future risk resulting from the proliferation of aerosol cans using 
flammable propellants) are sufficient to justify the costs of this 
rule. Moreover, there are other potential benefits that the FAA did not 
quantify, such as those fortuitous domestic cases in which the 
passengers and crew just barely escaped with their lives from fires 
initiated in Class D compartments.

Detection and Suppression Unit Cost Estimates

    Few comenters provided cost estimates; most referred to cost 
figures from the preliminary regulatory evaluation. One major carrier, 
however, provided detailed detection and suppression cost estimates 
(for two affected airplane models) that were substantially lower than 
FAA estimates. Even after including out-of-service costs (which the FAA 
estimates do not include for reasons discussed elsewhere in the 
preamble) the commenter's unit cost estimates were approximately equal 
to--and in one case lower than--those calculated by the FAA. This is 
consistent with anecdotal evidence gathered by the FAA since the 
publication of Notice 97-10: competitive forces have in many cases 
significantly bid down retrofit costs. From this evidence, the FAA 
concludes that the original cost assumptions (which are maintained in 
the final regulatory analysis) and benefit-cost findings are 
conservative.

The Cost of Diversions

    One commenter interpreted the economic analysis to imply that the 
FAA believes the costs associated with a false alarm are approximately 
$60 to $2,800 per event. ``Assuming that each of our fleet types would 
incur one additional diversion per year,'' this commenter writes, ``the 
cost is estimated to be $30,000 for a 727 and $50,000 for a DC-10.'' 
``Consequently,'' the commenter concludes, ``the costs per diversion of 
$60 to $2,800 are not valid estimates.''
    The FAA agrees that the cost per division is in the range suggested 
by the commenter--in fact, this is consistent with the diversion cost 
assumptions used in the preliminary regulatory evaluation. In any given 
year, however, most airplanes will not experience a diversion. The $60 
to $2,800 range is a calculation of the annualized false alarm costs 
per airplane--that is, the cost of a diversion weighted by the annual 
probability of a diversion.
    It is also worth noting that the regulatory evaluation accounts for 
the fact that the false alarm rate exhibited by detectors installed as 
result of this rule will be lower than the historical false alarm rate. 
Current-generation detectors, for example, make use of microprocessor 
technology that permits the system to discriminate between fire-
generated smoke and other non-hazardous particulates (water vapor, for 
example).

Downtime Costs

    Several commenters contend that the rule will require significant 
downtime, and, concomitantly, result in substantial lost revenue. The 
Air Transport Association estimates that ``it will cost $22,400 per 
airplane more to complete the program on a 3-year schedule compared to 
a 5-year schedule. For a fleet of 2,994 passenger airplanes and 321 
all-cargo airplanes [figures contained in Notice 97-10], the excess 
cost would be over $74 million.'' ``We do not think,'' ATA concludes, 
``that the marginal added benefits resulting from a 3-year schedule 
justifies the extra cost.'' The comment does not include specific 
details as to how the per-airplane cost estimate was derived.
    As noted earlier, the FAA has given considerable thought to the 
option of

[[Page 8045]]

extending the compliance deadline. Based on the information received in 
the comments, however, the FAA still believes that a three-year 
compliance schedule is the optimal compromise between cost and safety 
considerations. First, as noted earlier, design approval has already 
been granted for the installation of detection and suppression systems 
in some of the more numerous airplane models in service with Class D 
compartments. The comments provide no additional information that 
causes the FAA to alter its conclusion that fleetwide compliance can be 
achieved without additional downtime.
    Second, the FAA believes that revenue loss estimates provided by 
the airline industry are overstated. This follows since total industry 
losses cannot be calculated by multiplying net revenue loss (revenue 
minus variable operating costs) per airplane-day by the total number of 
down-days (the methodology apparently used in the ATA comment). While 
it is true that at different times during the compliance perid 
individual airlines will be affected to varying degrees, overall 
airline competition is approximately a constant-sum contest for 
passengers. That is, most passengers unable to book a flight of first 
preference (assuming aircraft unavailability as a result of this rule) 
will book another flight on the same or a competing airline. The fact 
that competition in many markets encourages airlines to increase 
schedule frequencies, even if available seats are plentiful, further 
mitigates the possible impact to the industry as a whole.1
---------------------------------------------------------------------------

    \1\ It should be noted that this observation is not inconsistent 
with the ``overbooking'' phenomenon. See, for example, Crandall, 
Robert L., ``The Unique U.S. Airline Industry,'' in the Handbook of 
Airline Economics, McGraw-Hill, 1995, p. 4. ``The influence of even 
small differences in departure time on customer buying behavior 
creates a powerful incentive for carriers to increase frequency, 
even when there are plenty of seats available on existing flights . 
. . [T]he fact that more capacity represents more frequency--and 
thus a more desirable product--gives every airline an incentive to 
use every airplane as intensively as possible. While this strategy 
makes sense for each individual carrier, it produces a tendency 
toward perpetual oversupply.''
---------------------------------------------------------------------------

Installation Labor Costs

    One foreign air carrier stated that C-check work for its fleet is 
broken down into a number of smaller units and accomplished over a 
longer period of time; therefore, it is likely that some airplanes will 
not have a 5-day downtime period for scheduled maintenance. (The 
proposed rulemaking would not be directly applicable to the foreign 
carrier; however, the comment is noted for illustrative purposes.) 
According to the commenter, this is likely to lead to unscheduled 
downtime. In addition, the commenter notes ``the estimated 30% 
reduction in labor hours, allowed in Notice 97-10 due to `existing' 
access,'' does not apply.
    Comments relating to additional downtime costs are addressed above. 
The FAA did note in the notice that scheduling the cargo compartment 
retrofit to coincide with scheduled maintenance could lower work hours 
by approximately 30%. The actual retrofit cost estimates, however, were 
not adjusted to account for this savings--this observation was made 
only to show that installation costs were conservatively estimated.

Summary of Final Analysis

    This analysis separately considers newly-manufactured airplanes and 
in-service airplanes. There are 21 transport-category airplane models 
operating under 14 CFR part 121 that have Class D compartments. 
Airplanes that are expected to be permanently retired from service 
before the year 2001 (the assumed compliance deadline), are omitted 
from the analysis. Based on changes proposed in this rule, the FAA now 
estimates that 2,991 passenger airplanes and 313 all-cargo airplanes 
will be affected by the rule. These estimates are based on an inventory 
compiled by the FAA's National Aviation Safety Data Analysis Center 
(NASDAC) from airplane-specific registry and insurance records.

Cost Estimates

    Cost estimates consider: (1) the costs associated with submitting 
compliance reports, (2) certfication expenses including one-time 
equipment and tooling costs, (3) fire detection and suppression 
equipment and installation costs, and (4) variable operating costs 
(fuel costs, maintenance and inspection costs, weight off-load costs, 
and the costs associated with unnecessary diversions initiated because 
of false alarms). In addition, it is assumed that Class D compartments 
in all-cargo airplanes will be converted to E compartments which do not 
require the installation of active suppression systems.
    The proposal will require each affected operator to submit a 
quarterly report listing the serial numbers of those airplanes in its 
fleet that are in compliance with the provisions of the rule and those 
that are not in compliance. One major carrier stated that, since 
records of modifications of this scale are computerized, the reporting 
requirement will involve less than one-half of one work hour. 
Initially, however, reports may take additional time to generate as 
carriers establish procedures, forms, etc. Also, records may not be 
computerized for smaller carriers. Thus, FAA conservatively estimates 
that, on average, the rule will require two additional work hours per 
quarter for each of the approximately 130 affected carriers. Assuming 
that each carrier will file 11 reports during the three year compliance 
period and that the fully burdened hourly compensation rate is $65, the 
estimated nominal cost of this provision to the entire industry is 
approximately $186,000 or $151,000 at present value (printing, postage, 
and other miscellaneous costs are assumed negligible).
    The FAA will also incur additional costs as a result of this 
reporting requirement. This analysis conservatively assumes that each 
of approximately 90 Flight Standards District Offices (FSDO) will, on 
average, spend approximately one-half of one work hour per quarter 
processing air carrier reports (some will spend no time, some 
considerably more than one-half hour). Also, approximately 20 hours per 
quarter will be required at FAA headquarters to tabulate these reports. 
Assuming the fully burdened hourly compensation rate is $38, the 
estimated nominal cost of this provision to FAA is approximately 
$27,000 or $22,000 at present value (data transmission costs between 
FAA headquarters and each of the FSDO's is assumed negligible).
    Type design approval of the detection and suppression systems will 
be required for most airplane models affected by the proposal. Type 
design approval will be in the form of a supplemental type certificate 
(STC) issued to an applicant other than the manufacturer; or, in the 
case of the manufacturer, either an STC or an FAA-approved type-design 
change. (The requirements for obtaining FAA approval are the same in 
either case.) The FAA assumes that type-design approval will be 
required for all airplane models affected by the proposed rule. Certain 
models will require a separate type-certification program for each 
different variant, while in other cases, all variants will be 
sufficiently similar that type-design approval could be granted for all 
variants following only one type-certification program. In some 
instances, an alternate Class C compartment configuration has already 
been FAA-approved. For those models or variants, no further type-
certification effort will be required.

[[Page 8046]]

    The cost of a type-certification program of this nature ranges from 
$315,000 to $1.8 million depending on the airplane model. In principle, 
no more than one type-certification program will be needed per model or 
variant; since operators could elect to utilize the same detection and 
suppression system installations on all affected airplanes of that 
particular type. If additional entities obtain separate type-design 
approvals for a given model or variant, they will do so for economic 
gain, not as a result of an FAA requirement to do so. Therefore, the 
analysis assumes the minimum number of type-certification programs 
theoretically necessary to accomplish the conversions.
    Detection-suppression system and installation cost estimates 
postulate that compartments will be fitted with a system of optical 
smoke detectors (configured to give indication of a fire within one 
minute) and a halon suppression system. The analysis further assumes a 
quantity of halon that will provide: (1) an initial ``knockdown'' 
discharge, and (2) the capability subsequently to maintain a 3 percent 
halon concentration for one hour. This is consistent with the standards 
currently in effect for Class C compartments.
    Although the U.S. bans the import of newly-produced halon, 
sufficient quantities of recycled halon are known to be available to 
meet the additional demand generated by this rule. The cost of halon 
has risen from approximately $2 per pound before production was banned 
to $20 per pound currently. This analysis assumes that halon used in a 
retrofit will be available at $20 per pound. Nominal equipment and 
installation unit (i.e. each airplane) costs range from $13,000 to 
$101,000 depending on the airplane model.
    Although the time to retrofit could be substantial, especially for 
airplanes with three Class D compartments, industry representatives 
state that conversions could be accomplished during a C-check, a 
scheduled maintenance check that occurs about once a year. C-checks are 
typically accomplished over a four- to five-day period. Conversions 
conducted concurrent with a C-check could reduce labor hours by as much 
as 30 percent, because many areas of the airplane are easily 
accessible. As noted previously, the comments received by the FAA do 
not provide any credible reasons that detection and suppression systems 
cannot be installed in all affected airplanes within three years while 
the airplanes are undergoing other scheduled maintenance. Therefore, 
this analysis attributes no foregone revenues due to downtime (i.e., 
time out-of-service) associated with these conversions.
    Depending on the airplane model and its configuration, installing 
fire suppression and detection systems will add between 7 and 300 
pounds to the empty weight of an airplane. This weight, in turn, will 
affect fuel consumption. Incremental fuel consumption costs were 
estimated for each airplane model based on the weight of additional 
equipment and suppression agent required, statistical estimates of the 
change in fuel consumption as a function of incremental weight by 
airplane type, and estimates of annual flight hours by airplane model. 
Annual per-airplane incremental fuel consumption estimates range from 
$50 to $4,900 depending on the airplane model.
    Inspection and maintenance of fire detection and suppression 
systems will include: (1) a leak check; (2) a visual inspection of the 
system; (3) a sensor test; and (4) a hydrostatic check of the fire 
bottles. The first three checks could be accomplished at each C-check, 
i.e., about once per year. A hydrostatic check will involve removing 
and replacing the fire bottle and will occur approximately once every 
five years. The bottle would be returned to the halon provider where it 
would be recharged and checked for leaks.
    Six work-hours at a burdened hourly rate of $60 will be required to 
conduct a leak check of the system of each compartment. A visual 
inspection of the system will require 1.5 hours per compartment at $60 
per hour. Checking the sensors will require about one hour per 
compartment. It will take two mechanics one hour at a burdened hourly 
rate of $60 to remove and replace a fire bottle. Fire-bottle vendors 
typically charge between $600 and $1,000, including shipping, to 
perform a hydrostatic test and recharge the bottles, irrespective of 
the size of the bottle. Annual unit maintenance and inspection costs, 
therefore, range from $700 to $2,100 depending on the airplane model.
    Under certain combinations, some departures might be weight-
constrained. In those cases, the additional weight of the fire 
detection and suppressions system will require an operator to off-load 
passengers or cargo. The cost of his off-load penalty is measured by 
estimating the number of displaced passengers or the amount of 
displaced cargo that cannot be accommodated. (On the basis of a 
statistical analysis of load factors and unaccommodated demand, the FAA 
estimates that 5 percent of the departures will be fully booked. 
Generally, most of these flights are not weight constrained, but this 
figure is a conservative assumption.) The cost of unaccommodated off-
load--approximately $0.30 per pound--is a weighted average of passenger 
and cargo revenue derived from revenue, enplanement, and freight data 
collected by the Bureau of Transportation Statistics, Office of Airline 
Information. Annual unit off-load penalties range from $30 to $800 
depending on the airplane model.
    Operators will also incur costs associated with flight diversions 
caused the false fire warnings. Costs include incremental airplane 
operating costs incurred during the diversion and passenger costs. 
Based on a recent FAA study of Service Difficulty Reports (SDR), 
proprietary aircraft operating data, and information from airborne fire 
detection equipment manufacturers, the FAA estimates that the frequency 
of false alarms is approximately 44 per million departures. In the 
absence of more detailed information, this analysis makes the 
conservative assumption that all false alarms result in a diversion. 
Annual diversion costs per airplane range from $60 to $2,800 depending 
on airplane type.
    Based on the above, the FAA estimates total life-cycle costs for 
the retrofitted fleet in nominal terms are approximately $294 million, 
or $193 million at present value. For a newly-manufactured airplane 
delivered to an ATA carrier, the rule will increase life-cycle costs 
for an average affected airplane by approximately $110,000 in nominal 
terms, or $60,000 at present value. Unit lifecycle costs for a newly-
manufactured airplane delivered to a non-ATA carrier will increase by 
approximately $179,000, or $100,000 at present value. (Per-airplane 
life cycle costs for ATA carriers are lower than for non-ATA carries 
since they are adjusted to account for voluntary installations of 
detection equipment. Similarly, estimated benefits for ATA carriers are 
adjusted--that is, reduced--to account for this voluntary action.)

Unfunded Mandates Reform Act Analysis

    Title II of the Unfunded Mandates Reform Act of 1995 requires 
Federal agencies to assess the effects of any Federal mandate in a 
proposal or final rule that may result in the expenditure by State, 
local, or tribal governments, or by the private sector of $100 million 
or more in any one year. This rule does not contain a Federal mandate 
meeting that criterion, therefore the requirements of the Act do not 
apply.

[[Page 8047]]

Benefits Estimates

    The benefits of detection and suppression systems depend on the 
degree to which the systems enable an airplane to avert a catastrophic 
accident in the event a fire occurs in a cargo or baggage compartment. 
Measuring this benefit, however, is problematic since it is determined 
not only by the relative fire-protection capabilities of Class C and 
Class D compartments, but on the probability that a fire will occur. 
Amendments to regulations--e.g. restrictions on the transportation of 
hazardous materials and more stringent burn--through requirements for 
compartment liners-also impinge on this analysis. (It should be noted, 
however, that the improvement standards for liners apply equally to 
both Class C and Class D compartments.)
    The expected (future) rate of fires occurring in cargo or baggage 
compartments estimated using historical accident and incident data from 
the National Transportation Safety Board (NTSB), FAA, insurance 
underwriters, and foreign aviation authorities. These records show that 
during the 20-year period between 1977 and 1996, there were 19 fires 
reported as having occurred worldwide in Class D and Class C 
compartments involving transport category airplanes while used in 
commercial service. During this period, air-carriers worldwide 
(excluding domestic operations within the former Soviet Union, the 
Russian Federation, and the Commonwealth of Independent States) 
accumulated approximately 224.5 million departures in transport 
category airplanes having Class C or Class D compartments. The event 
rate for fires occurring in Class D and Class C compartments is, 
therefore, approximately 0.085 per million departures.
    It must be noted that the event rate of 0.085 per million 
departures is based, for the most part, on service experience that 
occurred when consumer aerosol cans contained inert propellants. As 
described above under Background, the current use of highly-flammable 
propellants in consumer aerosol cans presents an additional hazard.
    The available evidence shows that in the majority of incidents, 
Class D compartments successfully contain fires. Of the 16 inflight 
fires occurring in Class D compartments, only four were reported to 
have resulted in casualties or substantial damage to the airplane. A 
precise estimate of the likelihood of injury or airplane damage in the 
event a fire occurs in a Class D compartment is difficult to compute, 
however, owing to the limitations of accident and incident information. 
In many cases, necessary details had to be estimated. Where the post-
event condition of the airplane is unknown, it is assumed that there 
was no damage. Where fatalities and injuries are unreported, it is 
assumed that there were no casualties. Where necessary, the number of 
occupants is estimated by applying the average load factor for that 
year by the average passenger capacity for a given airplane model.
    The expected reduction in the proportion of occupants fatally 
injured in an accident resulting from a fire occurring in a Class D 
compartment is estimated as the ratio of fatalities to total occupants. 
Of the 1,411 individuals involved in the accidents cited above, 523 
were fatally injured, representing approximately 37% of occupants.
    Applying the risk reduction estimate above to airplane-specific 
departure, capacity, and load factor information (and using the 
statistical value of $2.7 million to represent the economic benefit 
associated with each fatality averted), FAA estimates that the rule 
will yield benefits of approximately $461 million over the life of the 
affected in-service fleet, or approximately $230 million at present 
value.
    For a representative newly-manufactured airplane delivered to an 
ATA carrier, the FAA estimates that the rule will yield a life-cycle 
benefit of $280,000, or $94,000 at present value. For a newly-
manufactured airplane delivered to a non-ATA carrier, FAA estimates 
that the rule will yield a life-cycle benefit of $340,000, or $115,000 
at present value.
    In view of the above, the FAA finds that the benefits of the rule 
justify its costs. Specifically, for the affected in-service fleet, 
discounted benefits will exceed costs by a factor of approximately 
1.19. For affected newly-manufactured airplanes delivered to ATA 
carriers, discounted benefits will exceed costs by a factor of 1.57. 
For newly-manufactured airplanes delivered to non-ATA carriers, 
discounted benefits will exceed costs by a factor of 1.15.
    The FAA believes there are also non-quantifiable benefits contained 
in this proposal, including increased consumer confidence in the 
aviation industry due to the installation of detection and suppression 
systems. The White House Commission on Aviation Safety and Security 
recommended that the FAA include these non-quantifiable benefits in 
evaluating safety proposals. The FAA took these non-quantifiable 
benefits into consideration while formulating the proposal.

Regulatory Flexibility Analysis

    The Regulatory Flexibility Act of 1980 (RFA) was enacted by 
Congress to ensure that small entities are not unnecessarily and 
disproportionately burdened by government regulations. Specifically, 
the RFA requires federal agencies to prepare a regulatory flexibility 
analysis for any rule that will have a ``significant economic impact on 
a substantial number of small entities.'' The purpose of this analysis 
is to ensure that the agency has considered all reasonable regulatory 
alternatives that would minimize the rule's economic burdens for 
affected small entities, while achieving its safety objectives.
    Based on the initial Regulatory Flexibility Analysis and 
information received during the comment period, the FAA certifies that 
a significant number of small entities would be substantially affected 
by the proposed rule. In its preliminary analysis, the FAA concluded 
that there were no alternatives for small entities that could provide 
an equivalent level of safety at reduced cost. This conclusion was 
based on an exhaustive study of options that ranged from relatively 
low-cost, purely preventive approaches (e.g., banning certain types of 
material from air transport) to mitigative approaches such as: (1) 
retrofit of detection systems only, (2) a requirement for detection 
systems on newly manufactured aircraft only, (3) a requirement for 
detection and/or suppression systems for extended overwater operations 
only, (4) retrofit of detection and suppression systems, (5) a 
requirement for detection and suppression systems on newly manufactured 
aircraft only, (6) logical combinations of the above.
    Based on information received during the comment period, the FAA 
determines that this conclusion is correct with respect to 14 CFR part 
121 operations. There were no comments indicating that: (1) the rule 
would place small part 121 operators at a competitive disadvantage 
relative to large part 121 operators, or (2) that there were 
alternatives that could provide the same level of safety benefit at 
reduced cost to small operators. Significantly, no analysis was 
submitted indicating that fire safety risks for small part 121 carriers 
were different than for large part 121 carriers.
    As noted earlier, however, the FAA is reconsidering the options for 
part 135 operators (most of which are small). Several commenters note 
that the FAA's economic analysis did not consider smaller turbojet 
airplanes operated in nonscheduled service under part 135. These 
commenters also observe that

[[Page 8048]]

there are significant differences between nonscheduled part 135 
operations and operations conducted under 14 CFR part 121. These 
differences, they claim, render the likelihood of an inflight cargo 
fire extremely remote.
    The FAA agrees that further research is needed to evaluate the 
costs and benefits of detection and suppression systems for part 135 
operators--in particular, those engaged in nonscheduled operations 
involving turbojet airplanes originally designed for business travel.
    A copy of the regulatory evaluation prepared for this project may 
be examined in the Rules Docket or obtained from the person identified 
under the caption FOR FURTHER INFORMATION CONTACT.

International Trade impact Assessment

    Recognizing that regulations that are nominally domestic in nature 
often affect international trade, the Office of Management and Budget 
directs Federal Agencies to assess whether or not a rule or regulation 
would affect any trade-sensitive activity.
    This final rule could potentially affect international trade by 
burdening domestic manufacturers and air carriers with requirements 
that are not applicable to their foreign competitors, and thereby 
increase the relative price of domestically-produced goods and air 
travel provided by domestic operators.
    The FAA holds, however, that this final rule will have a negligible 
impact on international trade. First, the rule will not establish 
either a competitive advantage or disadvantage for domestic airframe 
manufacturers--both domestic and foreign firms will be unable to sell 
newly-manufactured transport category airplanes with Class D cargo or 
baggage compartments in the U.S. since they will be ineligible for air 
carrier service in this country after December 31, 2000. Second, as 
noted above, several major U.S. Air carriers have already voluntarily 
installed detection or detection and suppression systems in airplanes 
for which there is no existing requirement to do so. This is also true 
for at least one major foreign airline. Third, the proposed rule will 
primarily affect smaller narrow-body airplanes that are used on 
domestic routes. Foreign carriers, of course, are not permitted to 
compete on domestic routes. Most airplanes used in international 
service are larger models which are already equipped with cargo of 
baggage compartment fire-detection and suppression systems. Finally, 
foreign civil aviation authorities have indicated to the FAA that they 
expect to adept similar fire-detection and suppression requirements.

Federalism Implications

    The regulations adopted herein will not have substantial direct 
effects on the states, on the relationship between the national 
government and the states, or on the distribution of power or 
responsibilities among the various levels of government. In accordance 
with Executive Order 12612, it is, therefore, determined that this 
final rule will not have significant federalism implications to warrant 
the preparation of a Federalism Assessment.

International Compatibility

    The FAA has reviewed the corresponding international Civil Aviation 
Organization regulations, where they exist, and has identified no 
differences in these amendments and existing ICAO standards. The FAA 
has also reviewed the regulations of the Joint Aviation Authorities and 
has discussed similarities and differences in these proposed amendments 
and the foreign regulations.

Paperwork Reduction Act

    The Office of Management and Budget (OMB) has granted approval 
(control number 2120-0614, expiring August 31,2000) for the reporting 
required by this final rule. The costs and benefits of these proposed 
collection requirements are set forth in the section entitled ``Cost 
Estimates,'' Above.

Regulations Affecting Intrastate Aviation in Alaska

    Section 1205 of the FAA Reauthorization Act of 1996 (110 Stat. 
3213) requires the Administrator, when modifying regulations in Title 
14 of the CFR in a manner affecting intrastate aviation in Alaska, to 
consider the extent to which Alaska is not served by transportation 
modes other than aviation, and to establish such regulatory 
distinctions as he or she considers appropriate. The FAA, therefore, 
specifically requested comments on whether there is justification for 
applying the proposed rule differently to intrastate operations in 
Alaska. Although one commenter expressed a concern related to a 
particular Alaskan intrastate operation involving Lockheed Electras, no 
comments were received concerning such justification in general. Since 
no comments in that regard were received and the FAA is not aware of 
any justification for such regulatory distinction, the final rule is 
not applied differently to intrastate operations in Alaska.

List of Subjects

14 CFR Part 25

    Aircraft, Aviation safety.

14 CFR Part 121

    Aviation safety, Air carriers, Air transportation, Aircraft, 
Airplanes, Transportation.

Adoption of the Amendment

    In consideration of the foregoing, the FAA amends 14 CFR parts 25 
and 121 of the Federal Aviation Regulations (FAR) as follows:

PART 25--AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES

    1. The authority citation for part 25 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701, 44702 and 44704.

    2. Section 25.855(c) is revised to read as follows:


Sec. 25.855  Cargo or baggage compartments.

* * * * *
    (c) Ceiling and sidewall liner panels of Class C compartments must 
meet the test requirements of part III of appendix F of this part or 
other approved equivalent methods.
* * * * *
    3. Section 25.857 is amended by revising paragraph (c)(2) to read 
as follows and by removing and reserving paragraph (d):


Sec. 25.857  Cargo compartment classification

* * * * *
    (c) * * *
    (2) There is an approved built-in fire extinguishing or suppression 
system controllable from the cockpit.
* * * * *
    (d) [Reserved]
* * * * *
    4. Section 25.858 is amended by revising the section heading and 
introductory paragraph to read as follows:


Sec. 25.858  Cargo or baggage compartment smoke or fire detection 
systems.

    If certification with cargo or baggage compartment smoke or fire 
detection provisions is requested, the following must be met for each 
cargo or baggage compartment with those provisions:
 * * * * *

PART 121--OPERATING REQUIREMENTS: DOMESTIC, FLAG AND SUPPLEMENTAL 
OPERATIONS

    5. The authority citation for part 121 continues to read as 
follows:


[[Page 8049]]


    Authority: 49 U.S.C. 106(g), 40113, 40119, 44101, 44701-44702, 
44705, 44709-44711, 44716-44717, 44722, 44901, 44903-44904, 44912, 
46105.

    6. Section 121.314 is revised to read as follows:


Sec. 121.314  Cargo and baggage compartments.

    For each transport category airplane type certificated after 
January 1, 1958:
    (a) Each Class C or Class D compartment, as defined in Sec. 25.857 
of this Chapter in effect on June 16, 1986 (see Appendix L to this 
part), that is greater than 200 cubic feet in volume must have ceiling 
and sidewall liner panels which are constructed of:
    (1) Glass fiber reinforced resin;
    (2) Materials which meet the test requirements of part 25, appendix 
F, part III of this chapter; or
    (3) In the case of liner installations approved prior to March 20, 
1989, aluminum.
    (b) For compliance with paragraph (a) of this section, the term 
``liner'' includes any design feature, such as a joint or fastener, 
which would affect the capability of the liner to safely contain a 
fire.
    (c) After March 19, 2001, each Class D compartment, regardless of 
volume, must meet the standards of Secs. 25.857(c) and 25.858 of this 
Chapter for a Class C compartment unless the operation is an all-cargo 
operation in which case each Class D compartment may meet the standards 
in Sec. 25.857(e) for a Class E compartment.
    (d) Reports of conversions and retrofits. (1) Until such time as 
all Class D compartments in aircraft operated under this part by the 
certificate have been converted or retrofitted with appropriate 
detection and suppression systems, each certificate holder must submit 
written progress reports to the FAA that contain the information 
specified below.
    (i) The serial number of each airplane listed in the operations 
specifications issued to the certificate holder for operation under 
this part in which all Class D compartments have been converted to 
Class C or Class E compartments;
    (ii) The serial number of each airplane listed in the operations 
specification issued to the certificate holder for operation under this 
part, in which all Class D compartments have been retrofitted to meet 
the fire detection and suppression requirements for Class C or the fire 
detection requirements for Class E; and
    (iii) The serial number of each airplane listed in the operations 
specifications issued to the certificate holder for operation under 
this part that has at least one Class D compartment that has not been 
converted or retrofitted.
    (2) The written report must be submitted to the Certificate Holding 
District Office by July 1, 1998, and at each three-month interval 
thereafter.
    7. Appendix L to part 121 is amended by adding to the table an 
entry for Sec. 121.314(a) to read as follows:

Appendix L to Part 121--Type Certification Regulations Made Previously 
Effective

* * * * *

------------------------------------------------------------------------
                                                     Provisions: CFR/FR 
      Part 121  section        Applicable aircraft       references     
------------------------------------------------------------------------
                                                                        
                  *        *        *        *        *                 
Sec.  121.314(a)............  Transport category    Class C or D cargo  
                               airplanes type        or baggage         
                               certificated after    compartment        
                               January 1, 1958.      definition, 14 CFR 
                                                     25.857 in effect on
                                                     June 16, 1986, 14  
                                                     CFR parts 1 to 59, 
                                                     Revised 1/1/97, and
                                                     amended by         
                                                     Amendment 25-60, 51
                                                     FR 18243, May 16,  
                                                     1986.              
------------------------------------------------------------------------

    Issued in Washington, D.C. on February 10, 1998.
Jane F. Garvey,
Administrator.
[FR Doc. 98-3838 Filed 2-13-98; 8:45 am]
BILLING CODE 4910-13-M