[Federal Register Volume 60, Number 100 (Wednesday, May 24, 1995)]
[Proposed Rules]
[Pages 27449-27451]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-12712]
[[Page 27449]]
DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-16-AD]
Airworthiness Directives; McDonnell Douglas Model DC-9 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 all McDonnell Douglas Model DC-9
and C-9 (military) series airplanes. This proposal would require
replacement, inspection, and modification of the attach fittings of the
main landing gear (MLG). This proposal is prompted by reports of severe
structural damage and rupture of the integral fuel tank due to overload
of the MLG caused by adverse landing conditions. The actions specified
by the proposed AD are intended to minimize the possibility of primary
structural damage and rupture of the integral fuel tank due to overload
of the MLG; these conditions could lead to fuel spillage and a
resultant fire.
DATES: Comments must be received by July 19, 1995.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 95-NM-16-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; or at the FAA, Transport Airplane
Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount
Boulevard, Lakewood, California.
FOR FURTHER INFORMATION CONTACT: David Y. J. Hsu, Aerospace Engineer,
Airframe Branch, ANM-120L, FAA, Transport Airplane Directorate, Los
Angeles Aircraft Certification Office, 3960 Paramount Boulevard,
Lakewood, California 90712; telephone (310) 627-5323; 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-16-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-16-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
Since October 28, 1971, the FAA has received 11 reports of severe
structural damage and rupture of the wing integral fuel tank on
McDonnell Douglas Model DC-9 series airplanes. These occurrences
resulted from unpredictable overload of the main landing gear (MLG)
caused by adverse landing conditions. Model DC-9 series airplanes
having certain MLG fittings attached to the airframe in a particular
manner can sustain damage of the primary structure and rupture of the
integral fuel tank during certain abnormal landing conditions. Such
conditions include overrunning the runway, going off the runway,
skidding off the runway, taxiing into holes on a runway under repair,
landing off the runway, or a hard landing. Structural damage of this
type could compromise the integrity of the integral fuel tank. Should
the integral fuel tank subsequently rupture, it could result in fuel
spillage and a resultant fire.
The FAA has reviewed and approved McDonnell Douglas DC-9 Service
Bulletin 57-207, dated May 24, 1994, which references two other
McDonnell Douglas DC-9 service bulletins that contain procedures which,
when accomplished, will improve the capability of the MLG to break away
during abnormal landing operations. These service bulletins contain
procedures for replacement, inspection, and modification of the
attachments of the MLG attach fittings, as follows:
1. McDonnell Douglas DC-9 Service Bulletin 57-125, Revision 5,
dated November 5, 1990, describes procedures for replacement of MLG
attach fittings fabricated from 7079-T6 with fittings fabricated from
7075-T73 aluminum alloy forgings. These procedures are specified in the
service bulletin as Option 1.
2. McDonnell Douglas DC-9 Service Bulletin 57-148, Revision 5,
dated November 23, 1992. This service bulletin describes procedures for
the following:
--Enlarging the counterbores in the MLG attach fitting at the inboard
and outboard lower attachment holes, and performing a high frequency
eddy current inspection of the counterbore areas to detect cracks;
--Shotpeening selected areas of the MLG attach fitting;
--Replacing the lower attachment bolts of the inboard and outboard MLG
attach fittings with bolts having a different part number; and
--Replacing the fasteners through the lower flange of the MLG attach
fitting with interference fit fasteners.
These procedures are identified in the service bulletin as Phase 2.
Accomplishment of the actions described above will minimize the
possibility of primary structural damage, fuel tank rupture, and
possible fuel spillage due to unpredictable overload of the MLG caused
by abnormal landing operations.
Accomplishment of the procedures described in Revision 4 of
McDonnell Douglas DC-9 Service Bulletin 57-125 is required currently by
AD 90-18-03, amendment 39-6701 (55 FR 34704, August 24, 1990) to
address an unsafe condition identified as cracking due to stress
corrosion and subsequent degradation of the structural capability of
the affected airplanes. Revisions 3, 4, and 5 of that service bulletin
also specify procedures which, when accomplished, will improve the
[[Page 27450]] capability of the MLG to break away during abnormal
landing operations. Therefore, the FAA has determined that the unsafe
condition related to structural damage of the integral fuel tank, as
addressed by this proposed AD, also has been addressed adequately for
those airplanes on which Option 1 of Revision 3, 4, or 5 of the service
bulletin has been accomplished. However, the original version through
Revision 2 of McDonnell Douglas DC-9 Service Bulletin 57-125 do not
contain procedures that will improve the breakaway capability of the
MLG. The FAA has previously approved accomplishment of Option 1 in
accordance with the original version through Revision 2 of the service
bulletin, in lieu of Revision 4, as an acceptable alternative method of
compliance with AD 90-18-03. Therefore, for airplanes on which the
procedures described in the original version, Revision 1, or Revision 2
of McDonnell Douglas DC-9 Service Bulletin 57-125 have been
accomplished, the FAA finds that Phase 2, as specified in McDonnell
Douglas DC-9 Service Bulletin 57-148, also must be accomplished to
ensure that the unsafe condition specified in this proposed AD is
corrected.
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 one of the actions specified below, as
applicable. The actions would be required to be accomplished in
accordance with the service bulletins described previously.
1. Replacement of the attach fittings of both the right and left
MLG's would be required for airplanes on which Option 1 (or production
equivalent) of McDonnell Douglas DC-9 Service Bulletin 57-125 (original
version through Revision 5) has not been accomplished.
2. Inspection and modification of the attach fittings of both the
right and left MLG's would be required for airplanes on which Option 1
of McDonnell Douglas DC-9 Service Bulletin 57-125 (original version
through Revision 2) has been accomplished, but on which Phase 2 of
McDonnell Douglas DC-9 Service Bulletin 57-148 (original version
through Revision 5) has not been accomplished.
There are approximately 906 Model DC-9 and C-9 (military) series
airplanes of the affected design in the worldwide fleet. The FAA
estimates that 549 airplanes of U.S. registry would be affected by this
proposed AD.
The FAA estimates that the replacement specified as Option 1 in
McDonnell Douglas DC-9 Service Bulletin 57-125 has been accomplished on
all 549 airplanes of U.S. registry that would be affected by this
proposed AD. (As discussed previously, accomplishment of Option 1 was
required by AD 90-18-03.) Accordingly, the FAA finds that the proposed
replacement required by this AD would impose no additional economic
burden on any U.S. operator.
However, should an affected airplane be imported and placed on the
U.S. Register in the future, it would require approximately 425 work
hours to accomplish Option 1, at an average labor charge of $60 per
work hour. The cost of required parts would be $58,853 per airplane.
Based on these figures, the total cost impact for accomplishing Option
1 would be $84,353 per airplane.
The FAA estimates that all 549 airplanes of U.S. registry would be
required to accomplish the inspection and modification specified as
Phase 2 in McDonnell Douglas DC-9 Service Bulletin 57-148. It would
take approximately 36 work hours per airplane to accomplish Phase 2, at
an average labor rate of $60 per work hour. Required parts would cost
approximately $4,338 per airplane. Based on these figures, the total
cost impact on U.S. operators for accomplishing Phase 2 is estimated to
be $3,567,402, or $6,498 per airplane.
The total cost impact figure discussed above is based on
assumptions that no operator has yet accomplished this proposed
requirement (Phase 2) of this AD action, and that no operator would
accomplish that action in the future if this AD were not adopted.
As a result of recent communications with the Air Transport
Association (ATA) of America, the FAA has learned that, in general,
some operators may misunderstand the legal effect of AD's on airplanes
that are identified in the applicability provision of the AD, but that
have been altered or repaired in the area addressed by the AD. The FAA
points out that all airplanes identified in the applicability provision
of an AD are legally subject to the AD. If an airplane has been altered
or repaired in the affected area in such a way as to affect compliance
with the AD, the owner or operator is required to obtain FAA approval
for an alternative method of compliance with the AD, in accordance with
the paragraph of each AD that provides for such approvals. A note has
been included in this notice to clarify this long-standing requirement.
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. App. 1354(a), 1421 and 1423; 49 U.S.C.
106(g); and 14 CFR 11.89.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
McDonnell Douglas: Docket 95-NM-16-AD.
Applicability: All Model DC-9 and C-9 (military) series
airplanes, certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
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 (c) 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
[[Page 27451]] 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 minimize the possibility of primary structural damage and
rupture of the integral fuel tank due to overload of the main
landing gear (MLG) caused by adverse landing conditions, and
subsequent fuel spillage and a resultant fire, accomplish the
following:
(a) For airplanes on which Option 1 (or production equivalent)
has not been accomplished as specified in McDonnell Douglas DC-9
Service Bulletin 57-125 (original issue through Revision 5): Within
12 months after the effective date of this AD, replace the attach
fittings of both the right and left MLG's in accordance with Option
1 of the Accomplishment Instructions of McDonnell Douglas DC-9
Service Bulletins 57-125, Revision 5, dated November 5, 1990.
Note 2: Airplanes on which Option 1 has been accomplished as
specified in any of the following revisions of McDonnell Douglas DC-
9 Service Bulletin 57-125, are considered to be in compliance with
this AD and no further action is required by this AD:
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Service bulletin No. Revision level Date
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57-125....................... Revision 3...... October 28, 1982; or
Revision 4...... June 21, 1983; or
Revision 5...... November 5, 1990.
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(b) For airplanes on which Option 1 has been accomplished as
specified in McDonnell Douglas DC-9 Service Bulletin 57-125
(original version through Revision 2); but on which Phase 2 has not
been accomplished as specified in McDonnell Douglas DC-9 Service
Bulletin 57-148 (original version through Revision 5): Within 12
months after the effective date of this AD, inspect and modify the
attach fittings of both the right and left MLG's in accordance with
Phase 2 of McDonnell Douglas DC-9 Service Bulletin 57-148, Revision
5, dated November 23, 1992.
Note 3: Airplanes on which both Option 1 (or a production
equivalent) has been accomplished as specified in any of the
following revisions of McDonnell Douglas DC-9 Service Bulletin 57-
125; and Phase 2 (or a production equivalent) has been accomplished
as specified in any of the following revisions of McDonnell Douglas
DC-9 Service Bulletin 57-148; are considered to be in compliance
with this AD and no further action is required by this AD:
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Service bulletin No. Revision level Date
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57-125....................... (original)...... January 26, 1979; or
Revision 1...... February 16, 1979; or
Revision 2...... August 24, 1979;
and
57-148....................... (original)...... October 1, 1982; or
Revision 1...... June 8, 1983; or
Revision 2...... August 9, 1989; or
Revision 3...... September 11, 1990; or
Revision 4...... February 25, 1991; or
Revision 5...... November 23, 1992.
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(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 4: 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.
Issued in Renton, Washington, on May 18, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 95-12712 Filed 5-23-95; 8:45 am]
BILLING CODE 4910-13-U
