[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]



 ========================================================================
 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.
 
 ========================================================================
 

  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