[Federal Register Volume 60, Number 168 (Wednesday, August 30, 1995)]
[Proposed Rules]
[Pages 45108-45110]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-21490]
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Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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Federal Register / Vol. 60, No. 168 / Wednesday, August 30, 1995 /
Proposed Rules
[[Page 45108]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 95-NM-47-AD]
Airworthiness Directives; McDonnell Douglas Model DC-10-10, -15,
-30, and -40 Series Airplanes, and Model 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 certain McDonnell Douglas Model
DC-10-10, -15, -30, and -40 series airplanes, and Model KC-10A
(military) airplanes. This proposal would require inspection(s) to
detect cracks of the attach bolts of the front spar support fitting of
each wing. This proposal would also require replacement of attach bolts
of the front spar support fitting of the wing with corrosion-resistant
attach bolts. This proposal is prompted by a report of failure of the
attach bolts of the front spar fitting as a result of corrosion
pitting. The actions specified by the proposed AD are intended to
prevent such stress corrosion failure, which could lead to the failure
of the attach bolts of the front spar; this situation could result in
reduced structural integrity of the wing.
DATES: Comments must be received by October 25, 1995.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 95-NM-47-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, Transport Airplane Directorate,
Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard,
Lakewood, California.
FOR FURTHER INFORMATION CONTACT:
John Cecil, Aerospace Engineer, Airframe Branch, ANM-120L, FAA,
Transport Airplane Directorate, Los Angeles Aircraft Certification
Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137;
telephone (310) 627-5322; fax (301) 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-47-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-47-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has reviewed a report of failure of the attach bolts of the
front spar fitting on a Model DC-10 series airplane that had
accumulated 59,655 total flight hours and 22,271 total flight cycles.
Investigation revealed that the cause of such a failure has been
attributed to corrosion pitting that penetrated the protective plating.
The effects of such stress corrosion failure could lead to the failure
of the attach bolts of the front spar. This condition, if not detected
and corrected in a timely manner, could result in reduced structural
integrity of the wing.
The FAA has received and approved McDonnell Douglas DC-10 Service
Bulletin 57-126, dated October 30, 1992, which describes procedures for
ultrasonic inspection(s) to detect cracks of the attach bolts of the
front spar support fitting of each wing and replacement of cracked
attach bolts. This service bulletin also describes procedures for
replacement of all six attach bolts of the front spar support fitting
of each wing with corrosion resistant attach bolts, in lieu of the
repetitive ultrasonic inspections, if no cracks are detected. The
service bulletin recommends that such replacement of the attach bolts
be accomplished within 7 years.
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 ultrasonic inspection(s) to detect cracks of
the attach bolts of the front spar support fitting of each wing, and
replacement of cracked attach bolts. This proposed AD would also
require replacement of attach bolts of the front spar support fitting
of the wing with corrosion resistant attach bolts, in lieu of the
repetitive ultrasonic inspections, if no cracks are detected. The
actions would be required to be accomplished in accordance with the
service bulletin described previously.
Operators should note that certain actions proposed by this rule
would differ from the procedures
[[Page 45109]]
recommended in the referenced McDonnell Douglas service bulletin.
Specifically, the proposed rule would not require replacement of all
six attach bolts on each wing, if no cracks are detected (Condition 1,
Option II), at the 7-year compliance time recommended in the service
bulletin. Instead, this proposed rule would require, within 5 years
after the effective date of the final rule, replacement of a minimum of
five of the attach bolts of the front spar support fitting on each wing
with corrosion-resistant attach bolts, if no cracks are detected. This
proposed rule would also require, at the next pylon removal,
replacement of the remaining one attach bolt of the front spar support
fitting on each wing.
In developing an appropriate compliance time for this AD action,
the FAA considered not only the degree of urgency associated with
addressing the subject unsafe condition, but the manufacturer's
recommendation as to an appropriate compliance time, the availability
of required parts, and the practical aspect of installing the required
modification within an interval of time that parallels regularly
scheduled maintenance for the majority of affected operators. The FAA
points out that the parts required for the attach bolt replacement are
readily available; therefore, obtaining them within the 5 year proposed
compliance time should not pose a problem for any affected operator.
Further, the FAA reviewed an analysis submitted by the manufacturer
and determined that the ultimate strength of the front spar support
fitting is adequate with any combination of five attach bolts. The FAA
also determined that one of the six attach bolts can only be accessed
by removal of the engine/pylon assembly. Therefore, the FAA finds that
``the next pylon removal'' is an appropriate compliance time for
accomplishing the replacement of that one particular attach bolt.
There are approximately 420 Model DC-10-10, -15, -30, and -40
series airplanes, and Model KC-10A (military) airplanes of the affected
design in the worldwide fleet. The FAA estimates that 237 airplanes of
U.S. registry would be affected by this proposed AD, that it would take
approximately 6 work hours per airplane to accomplish the proposed
actions, and that the average labor rate is $60 per work hour. Required
parts would cost approximately $43,000 per airplane. Based on these
figures, the total cost impact of the proposed AD on U.S. operators is
estimated to be $10,276,320, or $43,360 per airplane.
The total 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.
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 regulation 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), 40101, 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
McDonnell Douglas: Docket 95-NM-47-AD.
Applicability: Model DC-10-10, -15, -30, and -40 series
airplanes, and Model KC-10A (military) airplanes; as listed in
McDonnell Douglas DC-10 Service Bulletin 57-126, dated October 30,
1992; 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 (d) of this AD 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 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 prevent reduced structural integrity of the wing, accomplish
the following:
(a) Within 18 months after the effective date of this AD,
perform an ultrasonic inspection to detect cracks in the 6 attach
bolts of the front spar support fitting of each wing, in accordance
with McDonnell Douglas DC-10 Service Bulletin 57-126, dated October
30, 1992.
(b) If no crack is detected during the inspection required by
paragraph (a) of this AD, accomplish paragraphs (b)(1) and (b)(2) of
this Ad.
(1) Repeat the ultrasonic inspection thereafter at intervals not
to exceed 18 months until the procedures required by paragraph
(b)(2) of this AD is accomplished; and
(2) Within 5 years after the effective date of this AD, replace
a minimum of 5 of the attach bolts of the front spar support fitting
on each wing with corrosion-resistant attach bolts, in accordance
with the service bulletin. At the next pylon removal after the
replacement, replace the remaining 1 attach bolt of the front spar
support fitting on each wing. Accomplishment of the replacement
constitutes terminating action for the repetitive inspection
requirements of this AD for that attach bolt.
(c) If any crack is detected during the inspection required by
paragraph (a) or (b)(1) of this AD, prior to further flight, replace
the cracked attach bolt with a corrosion-resistant attach bolt, in
accordance with the service bulletin. Accomplishment of such
replacement constitutes terminating action for the repetitive
inspection requirements of this AD for that attach bolt.
(d) 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.
[[Page 45110]]
(e) 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 August 24, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 95-21490 Filed 8-29-95; 8:45 am]
BILLING CODE 4910-13-M
