[Federal Register Volume 61, Number 21 (Wednesday, January 31, 1996)]
[Proposed Rules]
[Pages 3341-3343]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-1875]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-185-AD]
Airworthiness Directives; McDonnell Douglas Model DC-9 and Model
DC-9-80 Series Airplanes, Model MD-88 Airplanes, and Model 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 and Model DC-9-80 series airplanes, Model MD-88 airplanes, and
Model C-9 (military) series airplanes. This proposal would require
modification of the slant panel insulation blankets on the slant
pressure panel of the main landing gear. The proposal would also
require a visual inspection to detect discrepancies of the left and
right seal assemblies of the overwing emergency exit door, and
replacement of any discrepant door seal. This proposal is prompted by a
report that the flaps and landing gear did not extend or retract
properly due to water accumulation in the slant pressure panel area.
The actions specified by the proposed AD are intended to prevent such
water accumulation, which could result in the failure of the flaps or
landing gear to properly extend or retract.
DATES: Comments must be received by March 26, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
[[Page 3342]]
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 95-NM-185-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: Brent Bandley, Aerospace Engineer,
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification
Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone
(310) 627-5237; 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 95-NM-185-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. 95-NM-185-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received a report that the flaps and landing gear did
not extend or retract properly in flight on a Model DC-9-31 series
airplane. Investigation revealed that the potable water lines over the
center section had frozen and ruptured. The potable water leaked from
the water lines through the door seals of the overwing exit door and
accumulated in the slant pressure panel area. The water then dripped
and froze on various cables in the main wheel well area, which
prevented the flaps and landing gear from operating properly. If not
corrected, the possibility of water pooling in the slant pressure panel
area could continue, and consequently could drip and freeze on the
cables in the main wheel well area; this situation could then prevent
the flaps and landing gear form operating properly.
The potable water line installation, overwing exit door seals, and
slant pressure panel area on certain Model DC-9-80 series airplanes,
Model MD-88 airplanes, and C-9 (military) series airplanes are
essentially identical in configuration to that of Model DC-9 series
airplanes. Therefore, those airplanes may be subject to the same unsafe
condition identified on the Model DC-9 series airplanes.
The FAA has reviewed and approved McDonnell Douglas Service
Bulletin DC9-53-268, dated August 11, 1995, which describes procedures
for modification of the slant panel insulation blankets on the slant
pressure panel of the main landing gear. The modification involves
trimming the insulation blankets, sealing the trimmed area, and
reidentifying the insulation blankets. Accomplishment of the
modification will allow the water to drain out through the drain holes
and minimize the possibility of water accumulating in the slant
pressure panel area. The service bulletin also describes procedures for
a visual inspection to detect discrepancies (i.e., defects and constant
gap) of the left and right seal assemblies of the overwing emergency
exit door, and replacement of any discrepant door seal.
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 slant panel insulation
blankets on the slant pressure panel of the main landing gear. The
proposed AD would also require a visual inspection to detect
discrepancies of the left and right seal assemblies of the overwing
emergency exit door, and replacement of the discrepant door seal. The
actions would be required to be accomplished in accordance with the
service bulletin described previously.
There are approximately 1,500 McDonnell Douglas Model DC-9 and
Model DC-9-80 series airplanes, Model MD-88 airplanes, and Model C-9
(military) series airplanes of the affected design in the worldwide
fleet. The FAA estimates that 1,000 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 8 work
hours per airplane to accomplish the proposed actions, and that the
average labor rate is $60 per work hour. Based on these figures, the
cost impact of the proposed AD on U.S. operators is estimated to be
$480,000, or $480 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.
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.
[[Page 3343]]
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 USC 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
McDonnell Douglas: Docket 95-NM-185-AD.
Applicability: Model DC-9-10, -20, -30, -40, and -50 series
airplanes; Model DC-9-81 (MD-81), -82 (MD-82), -83 (MD-83), -87 (MD-
87) series airplanes; Model MD-88 airplanes; and Model C-9
(military) series airplanes; as listed in McDonnell Douglas Service
Bulletin DC9-53-268, dated August 11, 1995; 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 use the authority
provided in paragraph (b) of this AD to request approval from the
FAA. This approval may address either no action, if the current
configuration eliminates the unsafe condition; or different actions
necessary to address the unsafe condition described in this AD. Such
a request should include an assessment of the effect of the changed
configuration on the unsafe condition addressed by this AD. In no
case does the presence of any modification, alteration, or repair
remove any airplane from the applicability of this AD.
Compliance: Required as indicated, unless accomplished
previously.
To prevent water accumulation in the slant pressure panel area,
which could result in the failure of the flaps or landing gear to
properly extend or retract, accomplish the following:
(a) Within 24 months after the effective date of this AD,
accomplish paragraphs (a)(1) and (a)(2) of this AD, in accordance
with McDonnell Douglas Service Bulletin DC9-53-268, dated August 11,
1995.
(1) Modify the slant panel insulation blankets on the slant
pressure panel of the main landing gear.
(2) Perform a visual inspection to detect discrepancies (i.e.,
defects and constant gap) of the left and right seal assemblies of
the overwing emergency exit door. If any discrepancy is detected,
prior to further flight, replace door seal in accordance with the
service bulletin.
(b) 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 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Los Angeles ACO.
(c) 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 January 26, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-1875 Filed 1-30-96; 8:45 am]
BILLING CODE 4910-13-U
