[Federal Register Volume 61, Number 77 (Friday, April 19, 1996)]
[Proposed Rules]
[Pages 17261-17263]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-9690]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-212-AD]
Airworthiness Directives; McDonnell Douglas Model DC-10 and MD-11
Series Airplanes and KC-10A (Military) 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-10
and MD-11 series airplanes and KC-10A (military) airplanes. This
proposal would require repetitive inspections to detect corrosion or
failure of the steel Hi-Lok fasteners at the inboard flap inboard
track, and replacement of corroded/failed steel Hi-Lok fasteners with
inconel Hi-Lok fasteners. The proposed AD also provides for termination
of the repetitive inspections by replacing all of the steel Hi-Lok
fasteners with inconel Hi-Lok fasteners. This proposal is prompted by
reports of failed and/or corroded steel fasteners found in the inboard
flap inboard track due to stress corrosion. The actions specified by
the proposed AD are intended to prevent such stress corrosion, which
could result in binding of the flap and inability of the flap to extend
or retract; this situation may lead to asymmetric flap deployment and
subsequent reduced controllability of the airplane during flight.
DATES: Comments must be received by May 31, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 95-NM-212-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: Ron Atmur, Aerospace Engineer,
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification
Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone
(310) 627-5224; 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-212-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-212-AD, 1601 Lind Avenue SW., Renton, Washington
98055-4056.
Discussion of Service History
The FAA has received several reports of failed and/or corroded
fasteners found in the inboard flap inboard track on Model DC-10 series
airplanes. The failed fasteners were found on two airplanes, which had
accumulated 18,357 and 23,901 total landings, respectively.
Investigation revealed that the fasteners on these airplanes are made
of H-11 steel, which is susceptible to stress corrosion. Stress
corrosion in the fasteners in the inboard flap inboard track could
result in binding of the flap and inability of the flap to extend or
retract. If the flap fails to extend or retract, the resultant
asymmetric flap deployment could
[[Page 17262]]
result in reduced controllability of the airplane during flight.
The fasteners in the flap tracks on the Model DC-10 series
airplanes are identical to those installed on Model MD-11 series
airplanes. Therefore, the FAA has determined that Model MD-11 series
airplanes may be subject to the same failed/corroded fastener problem.
Discussion of Relevant Service Documents
The FAA has reviewed and approved McDonnell Douglas Service
Bulletin DC10-57-134, dated August 15, 1995 [for Model DC-10 series
airplanes and KC-10 (military) airplanes], and McDonnell Douglas
Service Bulletin MD11-57-031, dated August 15, 1995 (for Model MD-11
series airplanes). These service bulletins describe procedures for
repetitive visual inspections to detect corrosion or failure of the
steel Hi-Lok fasteners at the inboard flap inboard track; and
replacement of corroded/failed steel Hi-Lok fasteners with Hi-Lok
fasteners made of inconel.
These service bulletins also provide instructions for replacing all
steel Hi-Lok fasteners with inconel Hi-Lok fasteners, which, if
accomplished, eliminates the need for the repetitive inspections.
Replacement of steel fasteners with corrosion-resistant inconel
fasteners will minimize the possibility of fastener failure.
Discussion of the Proposed Rule
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 repetitive visual inspections to detect
corrosion or failure of the steel Hi-Lok fasteners at the inboard flap
inboard track. The proposed AD also would require replacement of
corroded/failed steel Hi-Lok fasteners with inconel Hi-Lok fasteners.
In addition, the proposed AD provides for an optional terminating
action for the repetitive inspection requirements by replacing all the
steel Hi-Lok fasteners with Hi-Lok fasteners made of inconel. The
actions would be required to be accomplished in accordance with the
service bulletins described previously.
The FAA is not proposing to mandate the replacement of all steel
Hi-Lok fasteners for several reasons:
1. Accessing the inboard flap inboard track area for inspection is
easily accomplished.
2. The corroded/failed fasteners are easily detectable by means of
a visual inspection.
3. The failure of a fastener may adversely affect the
controllability of the airplane; however, the visual inspections will
preclude the potential occurrence of multiple failed fasteners, which
could result in a catastrophic failure.
Differences Between the Proposed Rule and Relevant Service Documents
Operators should note that the proposed compliance time of 18
months for the initial and repetitive inspections differs from the
compliance times recommended in both of the referenced McDonnell
Douglas service bulletins:
Service Bulletin DC10-57-134 (for Model DC-10 series
airplanes) recommends a compliance time of 24 months.
Service Bulletin MD11-57-031 (for Model MD-11 series
airplanes) recommends a compliance time of 15 months. (The manufacturer
advised the FAA that it inadvertently specified a 15-month compliance
time in this service bulletin, and had intended that it be consistent
with the 24-month compliance time recommended in Service Bulletin DC10-
57-134.)
In developing an appropriate compliance time for this action, the
FAA considered not only the degree of urgency associated with
addressing the subject unsafe condition, but the susceptibility of the
subject area to stress corrosion cracking. In addition, the FAA finds a
compliance time of 18 months will allow the inspection to be performed
at a base during regularly scheduled maintenance where special
equipment and trained maintenance personnel will be available, if
necessary. In consideration of these items, the FAA finds that the
initial and repetitive visual inspections conducted at the proposed
compliance time of 18 months will better ensure that any detrimental
effect associated with stress corrosion will be identified and
corrected prior to the time that it could adversely affect the
fasteners in the inboard flap inboard track.
Cost Impact
There are approximately 514 McDonnell Douglas Model DC-10 and Model
MD-11 series airplanes, and KC-10A (military) airplanes of the affected
design in the worldwide fleet. The FAA estimates that 276 airplanes of
U.S. registry would be affected by the inspection requirements proposed
in this AD, that it would take approximately 2 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 inspection requirements on U.S. operators is estimated to be
$33,120, or $120 per airplane, per inspection cycle.
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.
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 95-NM-212-AD.
Applicability: All Model DC-10 and MD-11 series airplanes, and
KC-10A (military) airplanes, certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability
[[Page 17263]]
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 (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 prevent stress corrosion cracking in the fasteners in
the inboard flap inboard track, which could result in binding of the
flap and inability of the flap to extend or retract, accomplish the
following:
(a) For Model DC-10 series airplanes and KC-10A (military)
airplanes: Within 18 months after the effective date of this AD,
perform a visual inspection to detect corrosion or failure of the
steel Hi-Lok fasteners at the inboard flap inboard track in
accordance with McDonnell Douglas Service Bulletin DC-10-57-134,
dated August 15, 1995.
(1) If no corrosion or failure is detected, accomplish either
paragraph (a)(1)(i) or (a)(1)(ii) of this AD.
(i) Repeat the inspection required by paragraph (a) of this AD
thereafter at intervals not to exceed 18 months until paragraph
(a)(1)(ii) of this AD is accomplished.
(ii) Replace all steel Hi-Lok fasteners with inconel Hi-Lok
fasteners in accordance with McDonnell Douglas Service Bulletin DC-
10-57-134, dated August 15, 1995. Accomplishment of this replacement
constitutes terminating action for the repetitive inspection
requirements of paragraph (a)(1)(i) of this AD.
(2) If any corrosion or failure is detected, prior to further
flight, accomplish either paragraph (a)(2)(i) or (a)(2)(ii) of this
AD, in accordance with McDonnell Douglas Service Bulletin DC-10-57-
134, dated August 15, 1995.
(i) Replace all corroded/failed steel Hi-Lok fasteners with
inconel Hi-Lok fasteners in accordance with the service bulletin.
Repeat the visual inspection required by paragraph (a) of this AD
thereafter at intervals not to exceed 18 months until paragraph
(a)(2)(ii) of this AD is accomplished
(ii) Replace all steel Hi-Lok fasteners with inconel Hi-Lok
fasteners, in accordance with McDonnell Douglas Service Bulletin DC-
10-57-134, dated August 15, 1995. Accomplishment of this replacement
constitutes terminating action for the repetitive inspection
requirements of paragraph (a)(2)(i) of this AD.
(b) For Model MD-11 series airplanes: Within 18 months after the
effective date of this AD, perform a visual inspection to detect
corrosion or failures of the steel Hi-Lok fasteners at the inboard
flap inboard track in accordance with McDonnell Douglas Service
Bulletin MD11-57-031, dated August 15, 1995.
(1) If no corrosion or failures are detected, accomplish either
paragraph (b)(1)(i) or (b)(2)(ii) of this AD.
(i) Repeat the inspection required by paragraph (b) of this AD
thereafter at intervals not to exceed 18 months until paragraph
(b)(1)(ii) of this AD is accomplished.
(ii) Replace all steel Hi-Lok fasteners with inconel Hi-Lok
fasteners in accordance with McDonnell Douglas Service Bulletin
MD11-57-031, dated August 15, 1995. Accomplishment of this
replacement constitutes terminating action for the repetitive
inspection requirements of paragraph (b)(1)(i) of this AD.
(2) If any corrosion or failure is detected during the
inspection required by paragraph (b) of this AD, prior to further
flight, accomplish either paragraph (b)(2)(i) or (b)(2)(ii) of this
AD, in accordance with McDonnell Douglas Service Bulletin MD11-57-
031, dated August 15, 1995.
(i) Replace all corroded/failed steel Hi-Lok fasteners with
inconel Hi-Lok fasteners in accordance with the service bulletin.
Repeat the visual inspection required by paragraph (b) of this AD
thereafter at intervals not to exceed 18 months until paragraph
(b)(2)(ii) of this AD is accomplished.
(ii) Replace all steel Hi-Lok fasteners with inconel Hi-Lok
fasteners in accordance with McDonnell Douglas Service Bulletin
MD11-57-031, dated August 15, 1995. Accomplishment of this
replacement constitutes terminating action for the repetitive
inspection requirements of paragraph (b)(2)(i) of this AD.
(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 2: 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 April 15, 1996.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-9690 Filed 4-18-96; 8:45 am]
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