[Federal Register Volume 61, Number 221 (Thursday, November 14, 1996)]
[Rules and Regulations]
[Pages 58323-58326]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-28870]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-NM-53-AD; Amendment 39-9812; AD 96-23-07]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas Model DC-9-80 Series
Airplanes and Model MD-88 Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to McDonnell Douglas Model DC-9-80 series airplanes and
Model MD-88 airplanes, that requires visual/dye penetrant and
ultrasonic inspections to detect cracks in the vertical leg of the rear
spar lower cap of the wings, and various follow-on actions. This
amendment is prompted by reports indicating that, due to improper
torque tightening of the attach studs of the flap hinge fitting,
fatigue cracks were found in the vertical leg of the rear spar lower
cap of the wing. The actions specified by this AD are intended to
prevent such fatigue cracking, which, if not detected and corrected in
a timely manner, could result in loss of the spar cap, and consequent
damage to the spar cap web and adjacent wing skin structure; this
condition could lead to reduced structural integrity of the wing.
DATES: Effective December 19, 1996.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of December 19, 1996.
ADDRESSES: The service information referenced in this AD 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 Federal Aviation Administration (FAA), Transport
Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton,
Washington; or at the FAA, Los Angeles Aircraft Certification Office,
3960 Paramount Boulevard, Lakewood, California; or at the Office of the
Federal Register, 800 North Capitol Street, NW., suite 700, Washington,
DC.
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: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an airworthiness
directive (AD) that is applicable to certain McDonnell Douglas Model
DC-9-80 series airplanes and Model MD-88 airplanes series airplanes was
published as a notice of proposed rulemaking (NPRM) in the Federal
Register on August 27, 1996 (61 FR 44002). That action proposed to
require visual/dye penetrant and ultrasonic inspections to detect
cracks in the vertical leg of the rear spar lower cap of the wings, and
various follow-on actions.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Support for the Proposal
One commenter supports the proposed AD.
Discussion of Other Comments Received
During the development of the proposal for this AD action, the FAA
sought input on the technical and economic aspects from the
manufacturer, as well as from affected major U.S. operators through the
Air Transport Association (ATA) of America. In the process of
responding to these initial data-gathering inquiries, the ATA submitted
input to the FAA that had come from its member operators. Some of this
input was in the form of what appeared to be comments on what the
operators presumed would be the proposed AD; these comments went beyond
the technical data-gathering aspects of FAA's inquiries. Since it is
not the FAA's policy to request that type of input prior to the
issuance of a proposed rule, the FAA did not take those comments into
consideration when it issued the NPRM for this AD action.
When the NPRM was published in the Federal Register on August 27,
1996, it contained specific language indicating that the FAA was
requesting comments from the public on all aspects of the proposed AD.
However, neither the ATA nor its member operators resubmitted their
earlier (non-technical) comments in response to this request in the
NPRM. In such a situation, commenters are advised to resubmit their
comments to indicate to the FAA that their previous comments are still
relevant to the rule as it actually was proposed. Regardless of the
fact that these comments were not submitted to the FAA as part of the
formal rulemaking process, the FAA has
[[Page 58324]]
decided to respond to them in this final rule, since the comments raise
issues that may have continuing interest among other members of the
affected public.
The following discussion presents the FAA's disposition of each of
those comments:
Request To Increase Initial Threshold for Inspections
One U.S. operator requests that the threshold for conducting the
initial inspection of airplanes that have accumulated more than 15,000
total landings be specified as ``6,000 cycles or 3 years,'' whichever
is later. For these airplanes, the proposal specified a threshold of
1,800 landings after the effective date of the AD. The operator states
that a later threshold will allow it to schedule the inspections of its
affected fleet during regular maintenance intervals. Doing so will
minimize the economic burden that this operator would face in terms of
consequent downtime and flight schedule interruptions.
The FAA does not concur. The operator provided no technical
justification for revising this threshold as requested. Failure of a
spar cap is a significant safety issue, and the FAA has determined that
the inspection thresholds, as proposed, are warranted, based on the
effectiveness of the inspection procedure to detect cracks, and the
rate of crack growth in the spar cap at the subject area.
Additionally, the FAA points out that the relevant service
information has been available to operators since 1989 (the year that
the original version of McDonnell Douglas MD-80 Service Bulletin 57-184
was issued). Operators have had since that time to become aware of the
inspection and modification now required by this AD and to add those
actions to their individual maintenance plans. In fact, the FAA has
been advised that several operators have already done just that.
Further, the FAA does not consider it appropriate to include
provisions in an AD that are applicable to a single operator's unique
situation. However, paragraph (e) of the final rule does provide
affected operators the opportunity to apply for an adjustment of the
compliance time if sufficient data are presented to justify such an
adjustment.
Request for ``Credit'' if Actions Performed According to Earlier
Service Bulletin
Another operator requests that ``credit'' be given to operators who
have performed the inspection and/or modification in accordance with
the original version of McDonnell Douglas MD-80 Service Bulletin 57-
184, dated March 16, 1989. This operator previously accomplished the
now-required actions before Revision 1 of that service bulletin was
issued on December 22, 1994.
The FAA concurs. Although the proposal cited only Revision 1 of the
service bulletin as the appropriate source for service instructions,
the FAA finds that the instructions specified in the original version
of the service bulletin are equivalent. Therefore, use of either
service document is acceptable for compliance with the requirements of
this AD. The final rule has been revised to specify this.
Request To ``Justify'' Mandating the Service Bulletin
One operator questions the FAA's actions in mandating the
requirements of McDonnell Douglas MD-80 Service Bulletin 57-184. This
operator points out that the service bulletin was the subject of review
by the Service Action Requirements (SAR) committee meeting in August
1995. [NOTE: The SAR committee was formed as part of the actions that
were originally initiated by the Airworthiness Assurance Working Group
(AAWG), Model DC-9/MD-80 Task Group. This committee, comprised of
representatives from operators, the manufacturer, and the FAA, conducts
reviews of inspection and modification service bulletins that are
applicable to aging Model DC-9/MD-80 series airplanes; subsequent to
each review, the committee recommends to the FAA which of these service
bulletins should be made mandatory in order to reduce the potential for
major structural failure of the airplanes.] By a vote of 10 to 1, the
committee rejected the need to mandate the bulletin. This operator is
not aware of any change in airline experience that would warrant
reversing the committee decision and making the service bulletin
mandatory via an AD action.
The FAA responds to this comment by stating that, regardless of the
outcome of the SAR committee meeting, the FAA is responsible for
issuing AD actions at any time in order to correct unsafe conditions
that have been identified in airplanes. The FAA considers the potential
loss of a rear spar cap to be a significant safety issue warranting AD
action. As for additional recent and relevant service experience to
further justify this action, the FAA points out that, subsequent to the
issuance of the NPRM, one affected operator found an additional crack
in the same area that this AD requires to be inspected. In light of
this, the FAA maintains that this AD is not only appropriate, but
warranted.
Conclusion
After careful review of the available data, including the comments
noted above, the FAA has determined that air safety and the public
interest require the adoption of the rule with the change previously
described. The FAA has determined that this change will neither
increase the economic burden on any operator nor increase the scope of
the AD.
Cost Impact
There are approximately 489 Model McDonnell Douglas Model DC-9-80
series airplanes of the affected design in the worldwide fleet. The FAA
estimates that 306 airplanes of U.S. registry will be affected by this
AD, that it will take approximately 26 work hours per airplane to
accomplish the required actions, and that the average labor rate is $60
per work hour. Based on these figures, the cost impact of the AD on
U.S. operators is estimated to be $477,360, or $1,560 per airplane.
The cost impact figure discussed above is based on assumptions that
no operator has yet accomplished any of the 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 adopted herein will 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 final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this action (1) is
not a ``significant regulatory action'' under Executive Order 12866;
(2) is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action
and it is contained in the Rules Docket. A copy of it may be obtained
from the Rules Docket at the location provided under the caption
ADDRESSES.
[[Page 58325]]
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends 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:
96-23-07 McDonnell Douglas: Amendment 39-9812. Docket 96-NM-53-AD.
Applicability: Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83
(MD-83), DC-9-87 (MD-87) series airplanes and Model MD-88 airplanes,
as listed in McDonnell Douglas MD-80 Service Bulletin 57-184,
Revision 1, dated December 22, 1994; 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 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 prevent fatigue cracking in the vertical leg of the rear spar
lower cap of the wing, which could lead to reduced structural
integrity of the wing, accomplish the following:
Note 2: Actions specified in this AD that have been performed
prior to the effective date in accordance with McDonnell Douglas MD-
80 Service Bulletin 57-184, dated March 16, 1989, are considered
acceptable for compliance with the applicable requirement of this
AD.
(a) Visual/Dye Penetrant Inspection and Ultrasonic Inspection.
Perform visual/dye penetrant and ultrasonic inspections to detect
cracks in the vertical leg of the rear spar lower cap of the wings
below and in the adjacent area of the two lower attaching stud holes
for the inboard hinge fitting of the outboard flap at station
Xrs=164.000, in accordance with McDonnell Douglas MD-80 Service
Bulletin 57-184, Revision 1, dated December 22, 1994; at the time
specified in paragraph (a)(1), (a)(2), (a)(3), or (a)(4) of this AD,
as applicable.
(1) For airplanes that have accumulated less than 8,000 total
landings as of the effective date of this AD: Perform the inspection
prior to the accumulation of 10,000 landings or within 3,000
landings after the effective date of this AD, whichever occurs
later.
(2) For airplanes that have accumulated 8,000 or more total
landings but less than 10,000 total landings as of the effective
date of this AD: Perform the inspection within 3,000 landings after
the effective date of this AD.
(3) For airplanes that have accumulated 10,000 or more total
landings but less than 15,000 total landings as of the effective
date of this AD: Perform the inspection within 2,400 landings after
the effective date of this AD.
(4) For airplanes that have accumulated 15,000 or more total
landings as of the effective date of this AD: Perform the inspection
within 1,800 landings after the effective date of this AD.
(b) Condition 1 (No Cracks). If no crack is detected during any
inspection required by paragraph (a) of this AD, accomplish the
requirements of either paragraph (b)(1) or (b)(2) of this AD, in
accordance with McDonnell Douglas MD-80 Service Bulletin 57-184,
Revision 1, dated December 22, 1994.
(1) Condition 1, Option 1 (Terminating Action). Prior to further
flight, tighten the four mounting studs of the flap hinge fitting in
the rear spar caps (2 studs in the upper cap and 2 studs in the
lower cap) to the applicable torque value, in accordance with the
service bulletin. Accomplishment of this tightening of the mounting
studs of the flap hinge fitting constitutes terminating action for
the repetitive inspection requirements of paragraph (b)(2) of this
AD.
(2) Condition 1, Option 2 (Repetitive Inspection). Repeat the
visual/dye penetrant and ultrasonic inspections required by
paragraph (a) of this AD thereafter at intervals not to exceed 3,000
landings until paragraph (b)(1) of this AD is accomplished.
(c) Condition 2 (Cracks). If any crack is detected during any
inspection required by paragraph (a) or (b)(2) of this AD, prior to
further flight, perform a high frequency eddy current inspection to
confirm the existence of cracking, in accordance with McDonnell
Douglas MD-80 Service Bulletin 57-184, Revision 1, dated December
22, 1994. After this inspection, accomplish the requirements of
either paragraph (c)(1), (c)(2), or (c)(3) of this AD, as
applicable.
(1) No Cracking Confirmed. If no cracking is confirmed,
accomplish the requirements of either paragraph (b)(1) [``Condition
1, Option 1 (Terminating Action)''] or (b)(2) [``Condition 1, Option
2 (Repetitive Inspection)''] of this AD.
(2) Condition 2, Option 1 (Permanent Repair). If any cracking is
confirmed, prior to further flight, replace the entire spar cap or
accomplish the permanent splice repair of the spar cap, and tighten
the four mounting studs of the flap hinge fitting in the rear spar
caps (2 studs in the upper cap and 2 studs in the lower cap) to the
applicable torque value, in accordance with the service bulletin.
Accomplishment of this tightening of the mounting studs constitutes
terminating action for the repetitive inspection requirements of
paragraph (c)(3) of this AD.
(3) Condition 2, Option 2 (Temporary Repair). If cracking is
confirmed and it does not extend beyond the location limits and does
not exceed the maximum permissible crack length of 2 inches, prior
to further flight, accomplish the temporary repair modification of
the spar cap in accordance with the service bulletin. Thereafter,
repeat the eddy current inspection at intervals not to exceed 3,000
landings until paragraph (c)(2) of this AD is accomplished.
(i) If any crack progression is found during any repetitive eddy
current inspection following accomplishment of the temporary repair,
prior to further flight, contact the Manager, Los Angeles Aircraft
Certification Office, FAA, Transport Airplane Directorate, telephone
(310) 627-5237, fax (310) 627-5210, to establish the appropriate
repair or replacement interval.
Note 3: Operators should note that, unlike the recommended
compliance time of ``within 3,000 landings after discovery of
cracking,'' which is specified in the service bulletin as the time
for accomplishing the permanent splice repair or replacement of the
spar cap, this AD requires that operators contact the FAA prior to
further flight. The FAA finds that the repair/replacement interval
should be established based on the crack progression. Where there
are differences between the AD and the service bulletin in this
regard, the AD prevails.
(ii) If any new crack is found during any repetitive eddy
current inspection following accomplishment of the temporary repair,
prior to further flight, accomplish the permanent repair in
accordance with the service bulletin.
(d) Reporting Requirement. Within 10 days after accomplishing
the initial visual/dye penetrant and ultrasonic inspections required
by paragraph (a) of this AD, submit a report of the inspection
results (both positive and negative findings) to the Manager, Los
Angeles ACO, 3229 East Spring Street, Long Beach California 90806-
2425; telephone (310) 627-5237; fax (310) 627-5210. Information
collection requirements contained in this regulation have been
approved by the Office of Management and Budget (OMB) under the
provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et
seq.) and have been assigned OMB Control Number 2120-0056.
(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.
[[Page 58326]]
(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.
(g) The actions shall be done in accordance with McDonnell
Douglas MD-80 Service Bulletin 57-184, Revision 1, dated December
22, 1994. This incorporation by reference was approved by the
Director of the Federal Register in accordance with 5 U.S.C. 552(a)
and 1 CFR part 51. Copies may be obtained from McDonnell Douglas
Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846,
Attention: Technical Publications Business Administration,
Department C1-L51 (2-60). Copies may be inspected at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington; or at the FAA, Los Angeles Aircraft Certification
Office, 3960 Paramount Boulevard, Lakewood, California; or at the
Office of the Federal Register, 800 North Capitol Street, NW., suite
700, Washington, DC.
(h) This amendment becomes effective on December 19, 1996.
Issued in Renton, Washington, on November 5, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-28870 Filed 11-13-96; 8:45 am]
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