[Federal Register Volume 59, Number 140 (Friday, July 22, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-17860]
[[Page Unknown]]
[Federal Register: July 22, 1994]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 94-NM-51-AD]
Airworthiness Directives; McDonnell Douglas Model DC-10 Series
Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the supersedure of an existing
airworthiness directive (AD), applicable to certain McDonnell Douglas
Model DC-10 series airplanes, that currently requires inspection of the
wing rear spar lower cap aft tang fastener and the wing trailing edge
access door sill to detect fatigue cracking, and repair, if necessary.
This action would require installation of a crack preventative
modification of the wing rear spar lower cap, and follow-on
inspections. This proposal is prompted by reports of additional
cracking found in the current inspection area. The actions specified by
the proposed AD are intended to prevent propagation of cracks in the
subject area, which could compromise the structural integrity of the
airplane.
DATES: Comments must be received by October 11, 1994.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 94-NM-51-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, P.O. Box 1771, Long Beach,
California 90801-1771, Attention: Business Unit Manager, Technical
Administrative support, Dept. L51, M.C. 2-98 . This information may be
examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue,
SW., Renton, Washington; or at the FAA, Los Angeles Aircraft
Certification Office, Transport Airplane Directorate, 3229 East Spring
Street, Long Beach, California.
FOR FURTHER INFORMATION CONTACT: Maureen Moreland, Aerospace Engineer,
Airframe Branch, ANM-120L, Los Angeles Aircraft Certification Office,
FAA, Transport Airplane Directorate, 3229 East Spring Street, Long
Beach, California 90806-2425; telephone (310) 988-5238; fax (310) 988-
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 94-NM-51-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. 94-NM-51-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
On September 25, 1991, the FAA issued AD 91-21-05, amendment 39-
8052 (56 FR 50650, October 8, 1991), which is applicable to certain
McDonnell Douglas Model DC-10 series airplanes. That AD requires
repetitive inspections to detect fatigue cracking of the wing rear spar
lower cap aft tang and the wing trailing edge access door sill, and
repair of any cracking found. That action was prompted by reports of
fatigue cracks found in the wing rear spar lower cap aft tang on four
Model DC-10 series airplanes. This cracking was found during an
inspection conducted in accordance with the Supplemental Inspection
Document (SID) program; that program was required to be implemented by
AD 89-22-10, amendment 39-6330 (54 FR 42291, October 16, 1989). The
requirements of AD 91-21-05 are intended to prevent fatigue cracking in
the subject area. Such cracking, if not detected and corrected in a
timely manner, could compromise the structural integrity of the
airplane.
Since the issuance of that AD, there have been 10 additional
reports of fatigue cracks found in the wing rear spar lower cap aft
tang. Such cracking presents the same unsafe condition as addressed by
the existing AD 91-21-05.
Additionally, since the issuance of that AD, the manufacturer has
developed a crack preventative modification of the wing rear spar lower
cap aft tang and wing trailing edge access door sill that is intended
to minimize the possibility of cracking in these areas.
The FAA has reviewed and approved McDonnell Douglas Alert Service
Bulletin A57-123, Revision 1, dated June 8, 1993, which contains
procedures for conducting various inspections to detect fatigue
cracking of the wing rear spar lower cap aft tang fastener and the wing
trailing edge access door sill, and procedures for repairing any
cracking found. This revised service bulletin is essentially identical
to the original version, which was referenced in AD 91-21-05 as the
appropriate source of service information. The only relevant changes
are a revised listing of current operators of affected airplanes, and
the inclusion of additional repair options.
The FAA has also reviewed and approved McDonnell Douglas Service
Bulletin 57-123, dated June 8, 1993, that describes procedures for
installing a crack preventative modification of the wing rear spar
lower cap aft tang and wing trailing edge access door sill. This
modification entails replacing Taper-Lok fasteners with straight
titanium fasteners, and cold working the holes in the wing rear spar
lower cap forward and aft tangs between stations Xors=430.000 and
Xors=410.000. Accomplishment of this modification will minimize
the possibility of fatigue cracking in the subject areas.
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 supersede AD 91-21-05 to continue to require
repetitive inspections of the wing rear spar lower cap aft tang
fastener and the wing trailing edge access door sill to detect fatigue
cracking, and repair of any cracking found. These actions would be
required to be accomplished in accordance with either the original or
revised version of McDonnell Douglas Alert Service Bulletin A57-123.
This proposed AD would also require the eventual installation of
the crack preventative modification. Once this modification is
accomplished, repetitive post-modification inspections would be
required after the accumulation of a certain number of landings. These
actions would be required to be accomplished in accordance with
McDonnell Douglas Service Bulletin 57-123.
There are approximately 282 Model DC-10 series airplanes of the
affected design in the worldwide fleet. The FAA estimates that 175
airplanes of U.S. registry would be affected by this proposed AD.
The currently required inspections take approximately 8 work hours
per airplane to accomplish, at an average labor rate of $55 per work
hour. Based on these figures, the total cost impact of the current
inspection requirements of this AD on U.S. operators is estimated to be
$77,000, or $440 per airplane, per inspection.
The proposed modification would take approximately 12 work hours to
accomplish, at an average labor rate of $55 per work hour. Required
parts would cost between $3,730 and $6,730 per airplane, depending upon
the airplane model. Based on these figures, the total cost impact of
the proposed modification requirement of this AD on U.S. operators is
estimated to be between $4,390 and $7,390 per airplane.
The proposed post-modification inspections would take approximately
12 work hours per airplane to accomplish, at an average labor rate of
$55 per work hour. Based on these figures, the total cost impact of the
proposed post-modification inspection requirement of this AD on U.S.
operators is estimated to be $115,500, or $660 per airplane, per
inspection.
The total cost impact figure discussed above is based on
assumptions that no operator has yet accomplished any of the current or
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.
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 removing amendment 39-8052 (56 FR
50650, October 8, 1991), and by adding a new airworthiness directive
(AD), to read as follows:
McDonnell Douglas: Docket 94-NM-51-AD. Supersedes AD 91-21-05,
Amendment 39-8052.
Applicability: Model DC-10-10, -10F, and -15 series airplanes,
fuselage numbers through 379, inclusive; and Model DC-10-30, -30F,
and -40 series airplanes, fuselage numbers through 275, inclusive;
certificated in any category.
Compliance: Required as indicated, unless accomplished
previously.
To ensure the structural integrity of these airplanes,
accomplish the following:
(a) Except as provided in paragraphs (b) through (e) of this AD,
prior to the accumulation of 7,000 landings or within 30 days after
October 23, 1991 (the effective date of AD 91-21-05, amendment 39-
8051), which ever occurs later, conduct the initial inspections
specified in either paragraph (a)(1), (a)(2), or (a)(3) of this AD.
(1) Conduct an eddy current inspection of the wing rear spar
lower cap aft tang, and a dye penetrant inspection of the wing
trailing edge access door sill located between Xors=417.000 and
Xors=424.000, in accordance with Option III of McDonnell
Douglas Alert Service Bulletin A57-123, dated July 25, 1991, or
Revision 1, dated June 8, 1993. In addition, within 1,500 landings
after performing the eddy current and dye penetrant inspections,
conduct the inspections specified in either paragraph (a)(2) or
(a)(3) of this AD, and repeat them thereafter as indicated. Or
(2) Conduct an ultrasonic inspection of the area around the six
wing rear spar lower cap aft tang fastener holes, and a dye
penetrant inspection of the wing trailing edge access door sill
located between stations Xors=417.000 and Xors=424.000, in
accordance with Option II of McDonnell Douglas Alert Service
Bulletin A57-123, dated July 25, 1991, or Revision 1, dated June 8,
1993. Repeat these inspections thereafter at intervals not to exceed
1,900 landings until the modification required by paragraph (g) of
this AD is accomplished. Or
(3) Conduct an eddy current inspection of the six wing rear spar
lower cap aft tang fastener holes, and a dye penetrant inspection of
the wing trailing edge access door sill located between stations
Xors=417.000 and Xors=424.000, in accordance with Option I
of McDonnell Douglas Alert Service Bulletin A57-123, dated July 25,
1991, or Revision 1, dated June 8, 1993. Repeat these inspections
thereafter at intervals not to exceed 3,300 landings until the
modification required by paragraph (g) of this AD is accomplished.
(b) The requirements of paragraph (c) of this AD apply to
airplanes on which both of the following actions have been
accomplished:
(1) A dye penetrant inspection of the wing trailing edge access
door sill located between stations Xors=417.000 and
Xors=422.000 has been accomplished prior to October 23, 1991,
in accordance with McDonnell Douglas Service Bulletin 57-61,
Revision 2, dated August 15, 1990; and
(2) An eddy current inspection of the wing rear spar lower cap
aft tang has been accomplished prior to October 23, 1991, per DC-10
Supplemental Inspection Document, Principal Structural Element (PSE)
57.10.007 and 57.10.008, in accordance with McDonnell Douglas
Service Bulletin 57-61, Revision 2, dated August 15, 1990.
(c) For airplanes specified in paragraph (b) of this AD: Conduct
the initial inspections specified in either paragraph (c)(1) or
(c)(2) of this AD within 1,500 landings after accomplishing the
inspections (dye penetrant and eddy current) specified in paragraph
(b) of this AD, or within 30 days after October 23, 1991, whichever
occurs later.
(1) Conduct an ultrasonic inspection of the area around the six
wing rear spar lower cap aft tang fastener holes, and a dye
penetrant inspection of the wing trailing edge access door sill
located between stations Xors=417.000 and Xors=424.000, in
accordance with Option II of McDonnell Douglas Alert Service
Bulletin A57-123, dated July 25, 1991, or Revision 1, dated June 8,
1993. Repeat these inspections thereafter at intervals not to exceed
1,900 landings until the modification required by paragraph (g) of
this AD is accomplished. Or
(2) Conduct an eddy current inspection of the six wing rear spar
lower cap aft tang fastener holes, and a dye penetrant inspection of
the wing trailing edge access door sill located between stations
Xors=417.000 and Xors=424.000, in accordance with Option I
of McDonnell Douglas Alert Service Bulletin A57-123, dated July 25,
1991, or Revision 1, dated June 8, 1993. Repeat these inspections
thereafter at intervals not to exceed 3,300 landings until the
modification required by paragraph (g) of this AD is accomplished.
(d) The requirements of paragraph (e) of this AD apply to
airplanes on which both of the following actions have been
accomplished:
(1) A dye penetrant inspection of the wing trailing edge access
door sill located between stations Xors=417.000 and
Xors=422.000 has been accomplished prior to October 23, 1991,
in accordance with McDonnell Douglas Service Bulletin 57-61,
Revision 2, dated August 15, 1990; and
(2) An eddy current inspection of the wing rear spar lower cap
aft tang fastener holes located between stations Xors=417.000
and Xors=422.000 has been accomplished prior to October 23,
1991, per DPS 4.735-9, in accordance with McDonnell Douglas Service
Bulletin 57-61, Revision 2, dated August 15, 1990.
(e) For airplanes specified in paragraph (d) of this AD: Conduct
the initial inspections specified in either paragraph (e)(1) or
(e)(2) of this AD within 3,300 landings after the accomplishment of
the inspection specified in paragraph (d)(1) of this AD, or within
30 days after October 23, 1991, whichever occurs later.
(1) Conduct an ultrasonic inspection of the area around the six
wing rear spar lower cap aft tang fastener holes, and a dye
penetrant inspection of the wing trailing edge access door sill
located between stations Xors=417.000 and Xors=424.000, in
accordance with Option II of McDonnell Douglas Alert Service
Bulletin A57-123, dated July 25, 1991, or Revision 1, dated June 8,
1993. Repeat these inspections thereafter at intervals not to exceed
1,900 landings until the modification required by paragraph (g) of
this AD is accomplished. Or
(2) Conduct an eddy current inspection of the six wing rear spar
lower cap aft tang fastener holes, and a dye penetrant inspection of
the wing trailing edge access door sill located between stations
Xors=417.000 and Xors=424.000, in accordance with Option I
of McDonnell Douglas Alert Service Bulletin A57-123, dated July 25,
1991, or Revision 1, dated June 8, 1993. Repeat these inspections
thereafter at intervals not to exceed 3,300 landings until the
modification required by paragraph (g) of this AD is accomplished.
(f) If any crack(s) is found during any inspection conducted in
accordance with paragraphs (a) through (e) of this AD, prior to
further flight, repair in a manner approved by the Manager, Los
Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane
Directorate.
(g) Prior to the accumulation of 10,000 total landings, or
within 5 years after the effective date of this AD, whichever occurs
later, accomplish the crack preventative modification in accordance
with McDonnell Douglas Service Bulletin 57-123, dated June 8, 1993.
Accomplishment of this modification constitutes terminating action
for the inspection requirements of paragraphs (a) through (e) of
this AD.
(h) Prior to the accumulation of 10,000 landings after the
accomplishment of the crack preventative modification required by
paragraph (g) of this AD, conduct an inspection of the wing rear
spar lower cap in accordance with McDonnell Douglas Service Bulletin
57-123, dated June 8, 1993. Repeat this inspection thereafter in
accordance with the following schedule. Any crack(s) found during
any inspection required by this paragraph must be repaired, prior to
further flight, in accordance with a method approved by the Manager,
Los Angeles ACO, FAA, Transport Airplane Directorate.
(1) For Model DC-10-10, -10F, and -15 series airplanes: Repeat
the inspection at intervals not to exceed 4,550 landings.
(2) For Model DC-10-30 and -30F series airplanes: Repeat the
inspection at intervals not to exceed 2,810 landings.
(3) For Model DC-10-40 series airplanes: Repeat the inspection
at intervals not to exceed 3,400 landings.
(i) 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 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: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Los Angeles ACO.
(j) 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 July 18, 1994.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 94-17860 Filed 7-21-94; 8:45 am]
BILLING CODE 4910-13-U
