[Federal Register Volume 63, Number 14 (Thursday, January 22, 1998)]
[Proposed Rules]
[Pages 3267-3270]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-1427]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-14-AD]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas Model DC-10-10, -30,
and -40 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-10-10, -30, and -40 series airplanes. This proposal would require
replacement of certain taper-lok attachments and forward trunnion bolts
with new components that attach the left and right main landing gear
(MLG) to each wing. This proposal is prompted by a report indicating
that, due to overstrength of the forward trunnion bolt, an MLG broke
away and ruptured a wing fuel tank while an airplane was being operated
off the runway. The actions specified by the proposed AD are intended
to ensure that the MLG separates from the wing when it is subjected to
unpredictable overloads during abnormal operations, and to prevent
consequent primary structural damage to the airplane.
DATES: Comments must be received by March 9, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 97-NM-14-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: Ronald Atmur, Aerospace Engineer,
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification
Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone
(562) 627-5224; fax (562) 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
[[Page 3268]]
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 97-NM-14-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-114, Attention: Rules
Docket No. 97-NM-14-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received a report indicating that, while a McDonnell
Douglas Model DC-10-10 series airplane was being operated off the
runway, a main landing gear (MLG) broke away and ruptured the wing fuel
tank. The results of analysis and testing conducted by the manufacturer
revealed that certain fasteners (e.g., the forward trunnion bolt and
the bolts for the attach fitting), which attach the MLG to the rear
spar of the wing, are overstrength. Consequently, the MLG may not
separate from the airplane, as designed, when unpredictable overloads
are placed on the MLG during abnormal operations. This condition, if
not corrected, could result in primary structural damage to the
airplane.
Explanation of Relevant Service Information
The FAA has reviewed and approved McDonnell Douglas DC-10 Service
Bulletin 57-78, Revision 1, dated August 26, 1986 (for Model DC-10-10
series airplanes), which describes procedures for replacing 24 TL
taper-lok attachments that attach the left and right MLG attach fitting
assemblies on each wing with heat-treat TLH taper-lok attachments. This
service bulletin also describes procedures for replacing the forward
trunnion bolts on the left and right MLG of each wing with ``zero
margin'' trunnion bolts.
The FAA also has reviewed and approved McDonnell Douglas DC-10
Service Bulletin 57-79, Revision 1, dated September 21, 1979, as
revised by McDonnell Douglas DC-10 Service Bulletin 57-79, Service
Bulletin Change Notification, dated January 23, 1980 (for Model DC-10-
10 series airplanes). This service bulletin describes procedures for
replacing the 1\1/2\-inch-diameter bolts that attach the left and right
MLG attach fitting and rear spar of each wing with 1\1/4\-inch-diameter
bolts and bushings, and installing bolt retainers.
In addition, the FAA has reviewed and approved McDonnell Douglas
DC-10 Service Bulletin 57-82, dated February 19, 1980 (for Model DC-10-
30 and -40 series airplanes). This service bulletin describes
procedures for replacing the forward trunnion bolts of the left and
right MLG of each wing with ``zero margin'' trunnion bolts. For certain
groups of airplanes, the service bulletin also describes procedures for
replacing the 1\1/2\-inch-diameter bolts that attach the left and right
MLG attach fitting and rear spar of each wing with 1\1/4\-inch-diameter
bolts and bushings, and installing bolt retainers.
Accomplishment of the replacement of all of these fasteners will
allow the MLG to separate from the wing. This separation is intended to
minimize the possibility of primary structural damage to the airplane
when the MLG is subjected to unpredictable overloads during abnormal
operations.
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 of design, the
proposed AD would require accomplishment of the actions specified in
the service bulletins described previously in accordance with the
procedures specified in those service bulletins.
Cost Impact
For McDonnell Douglas Model DC-10-10 Series Airplanes
There are approximately 119 Model DC-10-10 series airplanes of the
affected design in the worldwide fleet, and 108 airplanes of U.S.
registry that would be affected by the proposed requirements for
replacement of taper-lok attachments and forward trunnion bolts. The
FAA estimates that it would take approximately 462 work hours per
airplane to accomplish these proposed actions, and that the average
labor rate is $60 per work hour. Required parts would cost
approximately $47,000 per airplane. Based on these figures, the cost
impact of these proposed actions on U.S. operators is estimated to be
$8,069,760, or $74,720 per airplane.
There are approximately 111 Model DC-10-10 series airplanes of the
affected design in the worldwide fleet, and 82 airplanes of U.S.
registry that would be affected by the proposed requirements for
replacement of larger attach bolts and installation of bolt retainers.
The FAA estimates that it would take approximately 500 work hours per
airplane to accomplish these proposed actions, and that the average
labor rate is $60 per work hour. Required parts would cost
approximately $11,734 per airplane. Based on these figures, the cost
impact of these proposed actions on U.S. operators is estimated to be
$3,422,188, or $41,734 per airplane.
For McDonnell Douglas Model DC-10-30 and DC-10-40 Series Airplanes
There are approximately 168 Model DC-10-30 and DC-10-40 series
airplanes of the affected design in the worldwide fleet, and 82
airplanes of U.S. registry that are identified as Groups I and II
airplanes in the relevant service bulletins and that would be affected
by the proposed requirements for replacement of larger attach bolts,
installation of bolt retainers, and replacement of forward trunnion
bolts. The FAA estimates that it would take approximately 576 work
hours per airplane to accomplish these proposed actions, and that the
average labor rate is $60 per work hour. Required parts would cost
approximately $20,000 per airplane. Based on these figures, the cost
impact of these proposed actions on U.S. operators is estimated to be
$4,473,920, or $54,560 per airplane.
There are approximately 20 Model DC-10-30 and DC-10-40 series
airplanes of the affected design in the worldwide fleet, and 6
airplanes of U.S. registry that are identified as Group III airplanes
in the relevant service bulletins and that would be affected by the
proposed requirements for replacement of forward trunnion bolts. The
FAA estimates that it would take approximately 76 work hours per
airplane to accomplish this proposed action, and that the average labor
rate is $60 per work hour. Required parts would cost approximately
$15,800 per airplane. Based on these figures, the cost impact of this
proposed action on U.S. operators is estimated to be $122,160, or
$20,360 per airplane.
The cost impact figures discussed above are based on assumptions
that no
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operator has yet accomplished the proposed action, and that no operator
would accomplish that action in the future if this AD were not adopted.
However, the FAA has been advised that the following actions have
been accomplished on Model DC-10-10 series airplanes in accordance with
the requirements of this proposed AD:
Taper-lok attachments and forward trunnion bolts have been
replaced on 77 U.S.-registered airplanes. Therefore, the future
economic cost impact of those proposed actions on U.S. operators is now
only $2,316,320.
Larger attach bolts have been replaced and bolt retainers
have been installed on 77 U.S.-registered airplanes. Therefore, the
future economic cost impact of those proposed actions on U.S. operators
is now only $208,670.
The FAA also has been advised that the following actions
have been accomplished on Model DC-10-30 and DC-10-40 series airplanes
in accordance with the requirements of this proposed AD:
Forward trunnion bolts and larger attach bolts have been
replaced and bolt retainers have been installed on 40 U.S.-registered
airplanes identified as Groups I and II airplanes in the relevant
service bulletins. Therefore, the future economic cost impact of those
proposed actions on U.S. operators is now only $2,291,520.
Forward trunnion bolts have been replaced on 3 U.S.-
registered airplanes identified as Group III airplanes in the relevant
service bulletins. Therefore, the future economic cost impact of this
proposed action on U.S. operators is now only $61,080.
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 97-NM-14-AD.
Applicability: Model DC-10-10, DC-10-30, and DC-10-40 series
airplanes; certificated in any category; as listed in the following
McDonnell Douglas service bulletins:
McDonnell Douglas DC-10 Service Bulletin 57-78,
Revision 1, dated August 26, 1986;
McDonnell Douglas DC-10 Service Bulletin 57-79,
Revision 1, dated September 21, 1979, as revised by McDonnell
Douglas DC-10 Service Bulletin Change Notification 57-79, dated
January 23, 1980; and
McDonnell Douglas DC-10 Service Bulletin 57-82, dated
February 19, 1980.
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 request approval for an
alternative method of compliance in accordance with paragraph (e) 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 main landing gear (MLG) separates from the
wing when it is subjected to unpredictable overloads during abnormal
operations, and to prevent consequent primary structural damage to
the airplane, accomplish the following:
(a) For Model DC-10-10 series airplanes, as listed in McDonnell
Douglas DC-10 Service Bulletin 57-78, Revision 1, dated August 26,
1986: Within 5 years after the effective date of this AD, accomplish
the requirements of paragraphs (a)(1) and (a)(2) of this AD, in
accordance with the service bulletin.
(1) Replace 24 TL taper-lok attachments that attach the left and
right MLG attach fitting assemblies on each wing with heat-treat TLH
taper-lok attachments in accordance with the service bulletin. And
(2) Replace each forward trunnion bolt on the left and right MLG
of each wing with a ``zero margin'' trunnion bolt in accordance with
the service bulletin.
Note 2: Replacement of taper-lok attachments and forward
trunnion bolts accomplished prior to the effective date of this AD
in accordance with McDonnell Douglas DC-10 Service Bulletin 57-78,
dated February 19, 1980, is considered acceptable for compliance
with the requirements of paragraphs (a)(1) and (a)(2) of this AD.
(b) For Model DC-10-10 series airplanes, as listed in McDonnell
Douglas DC-10 Service Bulletin 57-79, Revision 1, dated September
21, 1979, as revised by McDonnell Douglas DC-10 Service Bulletin
Change Notification 57-79, dated January 23, 1980: Within 5 years
after the effective date of this AD, replace each 1\1/2\-inch-
diameter bolt and bushing that attach the left and right MLG attach
fitting and rear spar of each wing with a 1\1/4\-inch-diameter bolt,
and install bolt retainers, in accordance with the service bulletin
and service bulletin change notification.
Note 3: Replacement of 1\1/2\-inch-diameter bolts and
installation of bolt retainers prior to the effective date of this
AD in accordance with McDonnell Douglas DC-10 Service Bulletin 57-
79, dated June 5, 1979, are considered acceptable for compliance
with the requirements of paragraph (b) of this AD.
(c) For Model DC-10-30 and DC-10-40 series airplanes: Except as
provided by paragraph (d) of this AD, within 5 years after the
effective date of this AD, accomplish the requirements of paragraph
(c)(1) or (c)(2) of this AD, as applicable, in accordance with
McDonnell Douglas DC-10 Service Bulletin 57-82, dated February 19,
1980.
(1) For airplanes identified as Groups I and II in the service
bulletin: Replace each forward trunnion bolt on the left and right
MLG of each wing with a ``zero margin'' forward trunnion bolt;
replace each 1\1/2\-inch-diameter bolt and bushing that attach the
left and right MLG attach fitting and rear spar of each wing with a
1\1/4\-inch-diameter bolt, and install bolt retainers, in accordance
with the service bulletin.
(2) For airplanes identified as Group III in the service
bulletin: Replace each forward trunnion bolt on the left and right
MLG of each wing with a ``zero margin'' trunnion bolt in accordance
with the service bulletin.
(d) For Model DC-10-30 and DC-10-40 airplanes: Installation of a
trunnion bolt having part number (P/N) ARG7558-501 or P/N ARG7558-
507 on the MLG, in accordance with AD 96-03-05, amendment 39-9502,
constitutes terminating action for the requirement to replace the
trunnion bolts for that landing gear, as required in paragraph
(c)(1) or (c)(2) of this AD.
[[Page 3270]]
(e) 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.
(f) 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 14, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-1427 Filed 1-21-98; 8:45 am]
BILLING CODE 4910-13-U
