[Federal Register Volume 61, Number 153 (Wednesday, August 7, 1996)]
[Proposed Rules]
[Pages 41039-41040]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-20074]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-68-AD]
RIN 2120-AA64


Airworthiness Directives; Jetstream Model 4100 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Jetstream Model 4100 
series airplanes. This proposal would require replacement of the 
existing decompression panel on the aft bulkhead of the toilet 
compartment with a modified decompression panel. This proposal is 
prompted by a report that a decompression panel that does not meet 
flammability requirements was installed on these airplanes during 
manufacture. The actions specified by the proposed AD are intended to 
prevent injury to the crew and passengers and damage to the airplane 
structure due to the incapability of the decompression panel to contain 
a fire.

DATES: Comments must be received by September 16, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-68-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056. Comments may be inspected at this location 
between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal 
holidays.
    The service information referenced in the proposed rule may be 
obtained from Jetstream Aircraft Limited, Customer Support Department, 
Prestwick International Airport, Ayrshire KA9 2RW, Scotland. This 
information may be examined at the FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: William Schroeder, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2148; fax (206) 227-1149.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 96-NM-68-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules 
Docket No. 96-NM-68-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Civil Aviation Authority (CAA), which is the airworthiness 
authority for the United Kingdom, recently notified the FAA that an 
unsafe condition may exist on certain Jetstream Model 4100 series 
airplanes. The CAA advises that a decompression panel that does not 
meet flammability requirements, as specified in sections 25.855 
(``Cargo or baggage compartments'') and 25.857 (``Cargo compartment 
classification'') of the Federal Aviation Regulations (14 CFR 25.855 
and 25.857), was installed on certain Model 4100 series airplanes 
during manufacture. This discovery was made during fire testing of a 
modified baggage bay bulkhead. Investigation revealed that the existing 
decompression panels installed on these airplanes are made of a 
material that is too thin to meet the test requirements for flame 
penetration resistance for cargo compartment liners specified in 
Appendix F of part 25 (``Airworthiness Standards: Transport Category 
Airplanes'') of the Federal Aviation Regulations (14 CFR part 25). 
Therefore, the panel does not fulfill the intent of the regulations, 
which, in part, is to assure the capability of the cargo compartment 
lining materials (e.g., the decompression panel) to contain a fire.
    If such a decompression panel is installed on an airplane and a 
fire occurs in the rear baggage compartment, the fire may not be 
completely confined without endangering the safety of the airplane or 
the occupants, and hazardous quantities of noxious gases could be 
released into the cabin. This condition, if not corrected, could result 
in injury to the crew and passengers and damage to the airplane 
structure.

Explanation of Relevant Service Information

    Jetstream has issued Service Bulletin J41-25-068, dated November 9, 
1995, which describes procedures for replacement of the existing 
decompression panel on the aft bulkhead of the toilet compartment with 
a modified decompression panel. The replacement involves removal of the 
existing decompression panel, installation of six new magnetic catches, 
and installation of a modified decompression panel having a thicker 
panel that will assure the capability of the cargo compartment lining 
materials to contain a fire. The CAA classified this service bulletin 
as mandatory in order to assure the continued airworthiness of these 
airplanes in the United Kingdom.

FAA's Conclusions

    This airplane model is manufactured in the United Kingdom and is 
type certificated for operation in the United States under the 
provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 
21.29) and the applicable bilateral airworthiness agreement. Pursuant 
to this bilateral airworthiness agreement, the CAA has kept the FAA 
informed of the situation described above. The FAA has examined the 
findings of the CAA, reviewed all available information, and determined 
that AD action is necessary for products of this type design that are 
certificated for operation in the United States.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or

[[Page 41040]]

develop on other airplanes of the same type design, the proposed AD 
would require replacement of the existing decompression panel on the 
aft bulkhead of the toilet compartment with a modified decompression 
panel. The actions would be required to be accomplished in accordance 
with the service bulletin described previously.

Cost Impact

    The FAA estimates that 17 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 6 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $60 per work hour. Required parts would be 
supplied by the manufacturer at no cost to operators. Based on these 
figures, the cost impact of the proposed AD on U.S. operators is 
estimated to be $6,120, or $360 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the proposed requirements of 
this AD action, and that no operator would accomplish those actions in 
the future if this AD were not adopted.

Regulatory Impact

    The regulations proposed herein would not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, will not have a significant economic impact, 
positive or negative, on a substantial number of small entities under 
the criteria of the Regulatory Flexibility Act. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (14 CFR part 39) as 
follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

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


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Jetstream: Docket 96-NM-68-AD.

    Applicability: Model 4100 series airplanes; constructors numbers 
41004 through 41017 inclusive, and 41019 through 41033 inclusive; 
certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (c) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent injury to the crew and passengers and damage to the 
airplane structure due to the incapability of the decompression 
panel to contain a fire, accomplish the following:
    (a) Within 60 days after the effective date of this AD, replace 
the existing decompression panel on the aft bulkhead of the toilet 
compartment with a modified decompression panel, in accordance with 
Jetstream Service Bulletin J41-25-068, dated November 9, 1995.
    (b) As of the effective date of this AD, no person shall install 
a decompression panel having part number 04125106-403 on the 
bulkhead assembly of any airplane.
    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Standardization Branch, ANM-113, 
FAA, Transport Airplane Directorate. Operators shall submit their 
requests through an appropriate FAA Principal Maintenance Inspector, 
who may add comments and then send it to the Manager, 
Standardization Branch, ANM-113.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (d) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

    Issued in Renton, Washington, on August 1, 1996.
John J. Hickey,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-20074 Filed 8-6-96; 8:45 am]
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