[Federal Register Volume 61, Number 179 (Friday, September 13, 1996)]
[Proposed Rules]
[Pages 48433-48435]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-23445]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-NM-95-AD]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas Model DC-9 Series
Airplanes and C-9 (Military) 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 McDonnell Douglas Model
DC-9 series airplanes and C-9 (military) series airplanes. This
proposal would require modification of the emergency internal release
system of the tailcone and the accessory compartment. This proposal is
prompted by a report that, due to failure of the tailcone release
system, the tailcone did not deploy on an airplane during an emergency
evacuation. The actions specified by the proposed AD are intended to
ensure that the emergency internal release system of the tailcone
performs its intended function in the event of an emergency evacuation.
The actions are also intended to prevent people on board the airplane
from striking their head on exposed metal frames in the tailcone area,
which could cause injury and delay or impede their evacuation during an
emergency.
DATES: Comments must be received by October 24, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
[[Page 48434]]
Attention: Rules Docket No. 96-NM-95-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 McDonnell Douglas Corporation, 3855 Lakewood
Boulevard, Long Beach, California 90846, Attention: Technical
Publications Business Administration, Department C1-L51 (2-60). This
information may be examined at the FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington.
FOR FURTHER INFORMATION CONTACT: Albert Lam, Aerospace Engineer,
Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft
Certification Office, 3960 Paramount Boulevard, Lakewood, California
90712; telephone (310) 627-5346; fax (310) 627-5210.
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-95-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-95-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received a report indicating that, during an emergency
evacuation of a McDonnell Douglas Model DC-9-10 series airplane, the
tailcone did not deploy when commanded. Extensive testing on the
airplane indicated that the tailcone release system did not work
properly. Subsequent investigations of other airplanes revealed that
numerous tailcone release systems on these airplanes were not in proper
working order.
Additionally, results of that testing has led the FAA to conclude
that the area where the internal release system of the tailcone is
located must be modified. The current location requires that the flight
attendant enter the tailcone area to jettison the tailcone. If the
flight attendant and evacuees enter the tailcone area during an
emergency and the release handle fails to deploy the tailcone, the
current configuration of the area makes it difficult for the passengers
to reverse direction; this may contribute to slowing down the emergency
egress. The FAA also finds that the metal frames in the tailcone area
are exposed and without padding; this could result in the passengers or
other personnel on board the airplane striking their head on these
frames and injuring themselves.
All of these conditions, if not corrected, could delay or impede
the evacuation of passengers during an emergency.
Explanation of Relevant Service Information
The FAA has reviewed and approved McDonnell Douglas Service
Bulletin DC-9 Service Bulletin 53-257, Revision 1, dated February 9,
1996, which describes procedures for modification of the emergency
internal release system of the tailcone. For all airplanes, this
modification involves installing a second internal release handle;
revising the electrical wiring; installing a light in close proximity
to the left-side of the doorway of the aft pressure bulkhead; and
installing emergency decals. For certain airplanes, this modification
also involves modifying and reidentifying the control panel assembly of
the ventral stairway. Accomplishment of this modification will minimize
the possibility of flight attendants encountering difficulty in
evaluating conditions aft of the tailcone exit door of the airplane
during an emergency evacuation. It also will allow trained or untrained
personnel better access to deploy the tailcone and slide.
The FAA also has reviewed and approved McDonnell Douglas DC-9
Service Bulletin 25-331, dated December 10, 1993, which describes
procedures for modification of the accessory compartment. This
modification involves installing overhead ceiling panels on the lower
side of three frames and a protective pad on the last frame in the aft
accessory compartment. Accomplishment of this modification will
increase protection to passengers/personnel from striking their head
against fuselage structure during an emergency.
Explanation of Requirements of Proposed Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other products of this same type design, the
proposed AD would require modification of the emergency internal
release system of the tailcone and the accessory compartment. The
actions would be required to be accomplished in accordance with the
service bulletins described previously.
Differences Between the Proposed Rule and the Relevant Service
Information
Operators should note that, unlike the recommended compliance time
of 12 months specified in Service Bulletin 25-331 for accomplishing the
modification of the accessory compartment, the proposed AD would
require the modification to be accomplished within 36 months. The FAA
has determined that a 36-month compliance time will not adversely
affect safety, and will allow the modification to be performed at a
base during regularly scheduled maintenance where special equipment and
trained maintenance personnel will be available, if necessary.
Other Relevant Rulemaking
The FAA has previously issued several other ADs that concern the
tailcone deployment system on Model DC-9 series airplanes:
1. AD 87-13-09, amendment 39-5665 (52 FR 24982, June 23, 1987),
requires the installation of a tailcone ``unlatched/missing'' warning
system.
2. AD 91-22-03, amendment 39-8063 (56 FR 60913, November 7, 1991),
requires the installation of a ``tailcone missing'' indication system.
3. AD 91-26-09, amendment 39-8122 (57 FR 789, December 5, 1991),
requires the replacement or modification of the internal and external
tailcone release system cable and handle assemblies.
[[Page 48435]]
4. AD 95-02-02, amendment 39-9121 (60 FR 4074, January 6, 1995),
requires an inspection of the tailcone release locking cable fitting
assembly, and modification or replacement, if necessary.
However, this proposed AD would not affect the current requirements
of any of those previously issued AD's.
Cost Impact
There are approximately 878 McDonnell Douglas Model DC-9 series
airplanes and C-9 (military) series airplanes of the affected design in
the worldwide fleet. The FAA estimates that 590 airplanes of U.S.
registry would be affected by this proposed AD.
The proposed modification of the emergency internal release system
would take approximately 7 work hours per airplane to accomplish, at an
average labor rate of $60 per work hour. Required parts would cost
approximately $6,660 per airplane. Based on these figures, the cost
impact of this modification proposed by this AD on U.S. operators is
estimated to be $4,177,200, or $7,080 per airplane.
The proposed modification of the accessory compartment would take
approximately 10 work hours per airplane to accomplish, at an average
labor rate of $60 per work hour. For the 395 airplanes identified as
``Group I'' in the referenced service bulletin, required parts would
cost approximately $1,777 per airplane. For the 195 airplanes
identified as ``Group 2'' in the referenced service bulletin, required
parts would cost $5,369 per airplane. Based on these figures, the cost
impact of this modification proposed by this AD on U.S. operators of
Group 1 airplanes is estimated to be $938,915, or $2,377 per airplane;
and on U.S. operators of Group 2 airplanes is estimated to be
$1,163,955, or $5,969 per airplane.
The cost impact figures discussed above are 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. However, the FAA has been
advised that 1 U.S.-registered airplanes has been inspected in
accordance with the requirements of this AD. Therefore, the future
economic cost impact of this rule on U.S. operators has been reduced by
that amount.
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:
McDonnell Douglas: Docket 96-NM-95-AD.
Applicability: Model DC-9-10, -20, -30, -40, and -50 series
airplanes and C-9 (military) series airplanes; as listed in
McDonnell Douglas DC-9 Service Bulletin 53-257, Revision 1, dated
February 9, 1996, and McDonnell Douglas DC-9 Service Bulletin 25-
331, dated December 10, 1993; operating in a passenger or passenger/
cargo configuration; certificated in any category.
Note 1: The requirements of this AD become applicable at the
time an airplane operating in an all-cargo configuration is
converted to a passenger or passenger/cargo configuration.
Note 2: 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 ensure that the emergency internal release system of the
tailcone performs its intended function in the event of an emergency
evacuation, accomplish the following:
(a) For airplanes listed in McDonnell Douglas DC-9 Service
Bulletin 53-257, Revision 1, dated February 9, 1996: Within 36
months after the effective date of this AD, modify the emergency
internal release system of the tailcone in accordance with the
service bulletin.
(b) For airplanes listed in McDonnell Douglas DC-9 Service
Bulletin 25-331, dated December 10, 1993: Within 36 months after the
effective date of this AD, modify the accessory compartment in
accordance with the service bulletin.
(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, Los Angeles Aircraft Certification
Office (ACO), 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, Los Angeles ACO.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Los Angeles ACO.
(d) Special flight permits may be issued in accordance with
Secs. 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 September 6, 1996.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-23445 Filed 9-12-96; 8:45 am]
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