[Federal Register Volume 62, Number 208 (Tuesday, October 28, 1997)]
[Rules and Regulations]
[Pages 55730-55732]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-28319]



[[Page 55730]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-95-AD; Amendment 39-10176; AD 97-22-05]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-9 Series 
Airplanes and C-9 (Military) Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive applicable 
to certain McDonnell Douglas Model DC-9 series airplanes and C-9 
(military) series airplanes, that requires modification of the 
emergency internal release system of the tailcone and the accessory 
compartment. This amendment 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 
this 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 also are intended to prevent 
people on board the airplane from striking their heads on exposed metal 
frames in the tailcone area, which could cause injury and delay or 
impede their evacuation during an emergency.

DATES: Effective December 2, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of December 2, 1997.

ADDRESSES: The service information referenced in this AD may be 
obtained from The Boeing Company, Douglas Products Division, 3855 
Lakewood Boulevard, Long Beach, California 90846, Attention: Technical 
Publications Business Administration, Dept. C1-L51 (2-60). This 
information may be examined at the Federal Aviation Administration 
(FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, 
SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, 
Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, 
Lakewood, California; or at the Office of the Federal Register, 800 
North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Albert H. Lam, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft 
Certification Office, 3960 Paramount Boulevard, Lakewood, California 
90712; telephone (562) 627-5346; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain McDonnell Douglas Model 
DC-9 series airplanes and C-9 (military) series airplanes was published 
in the Federal Register on September 13, 1996 (61 FR 48433). That 
action proposed to require modification of the emergency internal 
release system of the tailcone and the accessory compartment.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    Two commenters support the proposed rule.

Requests To Revise the Compliance Times of the Proposed 
Modifications

    One commenter requests that the compliance time for accomplishing 
the proposed modifications be extended from the proposed 36 months to 4 
years. The commenter states that such an extension will allow the 
modifications to be accomplished during a regularly scheduled heavy 
maintenance check and will allow time for procurement of additional 
modification kits. The commenter also states that such an extension 
will allow time for revising the affected manual; training of 
inspection and maintenance personnel; drafting, checking, and approving 
engineering documents; and testing and debugging the proposed 
modifications.
    Another commenter requests that the compliance times be shortened 
to 12 months. This commenter suggests that the proposed compliance 
times may be too long to fly with the potential of failure of the 
emergency internal release system of the tailcone.
    The FAA does not concur with either of these commenters' request. 
In developing an appropriate compliance time for these modifications, 
the FAA considered not only the degree of urgency associated with 
addressing the unsafe condition, but the availability of required parts 
and the practical aspect of installing the required modifications 
within an interval of time that parallels normal scheduled maintenance 
for the majority of affected operators. The manufacturer has advised 
that an ample number of required parts will be available for 
modification of the U.S. fleet within the proposed compliance period. 
Further, the FAA estimates that the affected airplanes will undergo two 
heavy maintenance checks during the proposed compliance time. In 
addition, the FAA finds that the 36-month compliance time is sufficient 
for operators to train their personnel and to incorporate the 
modifications into various documents. However, under the provisions of 
paragraph (c) of the final rule, the FAA may approve requests for 
adjustments to the compliance time if data are presented to justify 
such an adjustment.

Request To Remove Modification Requirement

    Two commenters state that the modification specified in McDonnell 
Douglas DC-9 Service Bulletin 53-257, Revision 1, dated February 9, 
1996 [which is referenced in paragraph (a) of the proposal as the 
appropriate source of service information] is difficult to accomplish 
and only adds more problems to the existing tailcone release system. 
One of these commenters contends that the tailcone release system 
described in the referenced service bulletin is unacceptable for an 
emergency exit system. This commenter also contends that the subject 
modification cannot be accomplished on airplanes equipped with aft 
ventral airstairs.
    From these comments, the FAA infers that the commenters are 
requesting that the proposed modification in paragraph (a) of the AD be 
removed from the final rule. The FAA does not concur. The FAA 
acknowledges that there were some problems associated with 
accomplishing the modification in accordance with the original issue of 
McDonnell Douglas DC-9 Service Bulletin 53-257, dated May 18, 1994. 
However, the FAA finds that these problems were addressed and corrected 
in Revision 1 of this service bulletin. The FAA recognizes that 
Revision 1 of the service bulletin does not address airplanes on which 
the aft ventral airstair handle has not been deactivated. However, 
based on a survey conducted by McDonnell Douglas, the FAA finds that 
affected operators are willing to deactivate the aft ventral airstair 
handle to accommodate the modification required by this AD. In 
addition, paragraph (c) of the AD contains a provision for requesting 
approval of an alternative method of compliance to address these types 
of unique circumstances.

Request To Add a New Requirement

    One commenter requests that paragraph (b) of the proposed AD be 
revised to include procedures for adding

[[Page 55731]]

protective padding between the added ceiling panel and beams, and on 
all other beams in the path of exiting passengers. The commenter 
contends that installation of ceiling panels [as required by paragraph 
(b) of the AD] provides a false sense of security and guidance to the 
flight attendants and evacuees. The commenter states that the ceiling 
panels could be damaged easily by tall and/or unruly passengers during 
emergency egress, which could expose the beams and supporting 
structure. Thus other passengers could strike their heads against the 
overhead beams. The commenter also states that the ceiling panels could 
detach from its support structure during an actual emergency, and 
consequently, also allow exposure of the beams and supporting 
structure. Further, the commenter states that the ceiling panels could 
fall in the path of the passengers that are exiting from the airplane. 
The FAA does not concur. The FAA has determined that installation of 
ceiling panels on the lower side of three frames and installation of a 
protective pad on the last frame in the aft accessory compartment 
provides an acceptable level of safety. In addition, the FAA finds that 
such an installation is comparable to other panel installations 
throughout the airplane. However, under provisions of paragraph (c) of 
the final rule, operators may apply for approval of an alternative 
methods of compliance if sufficient justification is presented to the 
FAA.

Request To Address Deficiencies With Existing Tailcone Release 
System

    One commenter states that the existing tailcone release system 
contains many design and reliability deficiencies. The commenter points 
out that the proposed AD does not specify any requirements to replace 
or repair the existing tailcone release system. The commenter also 
contends that, due to such deficiencies, the new interior release 
handle [installed in accordance with the requirements of paragraph (b) 
of the proposed AD] will fail to perform its intended function. From 
this comment, the FAA infers that the commenter is requesting that the 
FAA address the problems associated with the existing tailcone release 
system in the proposed AD. The FAA does not concur. The FAA has 
previously issued several other AD's that concern the tailcone 
deployment system on Model DC-9 series airplanes, which was discussed 
previously in the Other Relevant Rulemaking Section in the preamble to 
the NPRM. Therefore, the FAA finds no change to the final rule is 
necessary.

Request To Revise the Proposed Modification of the Emergency Internal 
Release System

    One commenter requests that the existing tailcone release system be 
replaced with an electro-mechanical system, which can be actuated from 
inside the airplane. The commenter states that it is more cost 
effective to install a modern and efficient system (i.e., electro-
mechanical system), rather than a system with design technology 
standards that are 25 to 30 years old. The commenter also states that 
the existing system does not meet industry expectations. The FAA does 
not concur. The modification required by paragraph (b) of this AD was 
developed with operator, manufacturer, and FAA concurrence based on 
cost and technical feasibility. However, under the provisions of 
paragraph (c) of this AD, operators may apply for the approval of an 
alternative method of compliance, if sufficient justification is 
presented to the FAA.

Request To Revise Various Manufacturer Manuals

    One commenter requests that the FAA require the manufacturer, 
rather than the affected operator(s), to update the affected 
Illustrated Parts Catalog, Airplane Maintenance Manual, Structural 
Repair Manual, and Wiring Diagram Manual to ensure continued 
airworthiness of the tailcone release system. The commenter states that 
an operator, who does not have ``experience'' with the modification 
required by the proposed AD, could enter erroneous information into 
these manuals. The FAA does not concur. The FAA finds that the subject 
service documents are not necessary to accomplish the modifications 
required by this AD. The FAA has been informed that the manufacturer is 
in the process of revising the DC-9 Airplane Maintenance Manual (AMM) 
to comply with the continued airworthiness requirements and will make 
the AMM available to operators.

FAA's Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule as proposed.

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 will be affected by this AD.
    The modification of the emergency internal release system will take 
approximately 7 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts will cost approximately 
$6,660 per airplane. Based on these figures, the cost impact of this 
modification required by this AD on U.S. operators is estimated to be 
$4,177,200, or $7,080 per airplane.
    The modification of the accessory compartment will 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 will 
cost approximately $1,777 per airplane. For the 195 airplanes 
identified as ``Group 2'' in the referenced service bulletin, required 
parts will cost $5,369 per airplane. Based on these figures, the cost 
impact of this modification required 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 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 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 and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

[[Page 55732]]

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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:

97-22-05--McDonnell Douglas: Amendment 39-10176. 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 
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.
    (e) The actions shall be done in accordance with 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. This incorporation by reference was approved by 
the Director of the Federal Register in accordance with 5 U.S.C. 
552(a) and 1 CFR part 51. Copies may be obtained from McDonnell 
Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 
90846, Attention: Technical Publications Business Administration, 
Department C1-L51 (2-60). Copies may be inspected at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or at the FAA, Transport Airplane Directorate, Los 
Angeles Aircraft Certification Office, 3960 Paramount Boulevard, 
Lakewood, California; or at the Office of the Federal Register, 800 
North Capitol Street, NW., suite 700, Washington, DC.
    (f) This amendment becomes effective on December 2, 1997.

    Issued in Renton, Washington, on October 17, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-28319 Filed 10-27-97; 8:45 am]
BILLING CODE 4910-13-U