[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]
BILLING CODE 4910-13-U