[Federal Register Volume 59, Number 35 (Tuesday, February 22, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-3754]


[[Page Unknown]]

[Federal Register: February 22, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 93-NM-134-AD; Amendment 39-8828; AD 94-04-08]

 

Airworthiness Directives; McDonnell Douglas Model DC-10-10, -10F, 
-15, -30, -30F, -40, and -40F Series Airplanes, and Model KC-10A 
(Military) Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain McDonnell Douglas Model DC-10 series airplanes 
and Model KC-10A (military) airplanes, that requires inspections to 
detect cracking in the No. 2 engine pylon lower spar forward mount and 
thrust link fitting attach bolts, replacement of cracked bolts, and the 
eventual replacement of all bolts made of H-11 material with bolts made 
of Inconel. This amendment is prompted by reports of failures of these 
attach bolts due to stress corrosion. The actions specified by this AD 
are intended to prevent failure of the attach bolts, which could reduce 
the fail-safe capability of the attachment assembly.

DATES: Effective March 24, 1994.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of March 24, 1994.

ADDRESSES: The service information referenced in this AD 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, Mail Code 2-98. 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, Transport Airplane Directorate, Los Angeles 
Aircraft Certification Office, 3229 East Spring Street, Long Beach, 
California; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: John Cecil, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Transport Airplane Directorate, Los 
Angeles Aircraft Certification Office, 3229 East Spring Street, Long 
Beach, California 90806-2425; telephone (310) 988-5322; fax (310) 988-
5210.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations to include an airworthiness directive (AD) that is 
applicable to certain McDonnell Douglas Model DC-10 series airplanes 
and Model KC-10A (military) airplanes was published in the Federal 
Register on October 26, 1993 (58 FR 57568). That action proposed to 
require inspections to detect cracking in the No. 2 engine pylon lower 
spar forward mount and thrust link fitting attach bolts, replacement of 
cracked bolts, and the eventual replacement of all bolts made of H-11 
material with bolts made of Inconel.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    One commenter supports the proposal.
    Two commenters request that the proposed compliance time for the 
inspections be extended to coincide with normally scheduled maintenance 
intervals. These commenters suggest that if the compliance times were 
extended to 24 months, the confusion and expense of special scheduling 
could be avoided. The FAA does not concur. In developing the proposed 
compliance time, the FAA primarily considered analyses of the mode of 
failure of the subject bolts due to stress corrosion, as well as the 
service history of the fleet. Based on this data and the safety 
implications presented by loss of fail-safe capability of the 
attachment assembly should the bolts fail, the FAA has determined that 
the proposed compliance times of 12 months for the initial inspection 
and 18 months for the repetitive inspection interval are both 
appropriate and warranted. Further, the FAA took into account the 
average utilization rate of the affected fleet, the practical aspects 
of an orderly inspection of the fleet during regular maintenance 
periods, and the availability of required replacement parts. The 
compliance times as proposed should allow ample time for the 
inspections to be conducted concurrently with scheduled maintenance, 
thereby minimizing the costs associated with special airplane 
scheduling. In light of all of these factors, the FAA considers that 
any extension of the compliance intervals to be unacceptable.
    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 as proposed.
    There are approximately 354 Model DC-10 series airplanes and Model 
KC-10A airplanes of the affected design in the worldwide fleet. The FAA 
estimates that 206 airplanes of U.S. registry will be affected by this 
AD
    The inspections required by this AD will 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 
inspections requirements of this AD on U.S. operators is estimated to 
be $90,640, or $440 per airplane, per inspection cycle.
    The replacement actions required by this AD will take approximately 
8 work hours per airplane to accomplish, at an average labor rate of 
$55 per work hour. Required parts will cost approximately $2,700 per 
airplane. Based on these figures, the total cost impact of the 
replacement actions of this AD on U.S. operators is estimated to be 
$646,840, or $3,140 per airplane.
    The total cost impact figures discussed above are 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.
    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.

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 14 CFR part 
39 of the Federal Aviation Regulations 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 adding the following new 
airworthiness directive:

94-04-08 McDonnell Douglas: Amendment 39-8828. Docket 93-NM-134-AD.

    Applicability: Model DC-10-10, -10F, -15, -30, -30F, -40, and -
40F series airplanes, and KC-10A (military) airplanes; having 
fuselage numbers 1 though 374 inclusive; certificated in any 
category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent failure of the No. 2 engine pylon lower spar forward 
mount and thrust link fitting attach bolts, which could reduce the 
fail-safe capability of the attachment assembly, accomplish the 
following:
    (a) Within 12 months after the effective date of this AD, 
perform an ultrasonic inspection to detect cracking of the No. 2 
engine pylon lower spar forward mount and thrust link fitting attach 
bolts made of H-11 material, in accordance with McDonnell Douglas 
DC-10 Service Bulletin 54-100, Revision 1, dated September 17, 1993.
    (1) If no cracking is detected, repeat the ultrasonic inspection 
thereafter at intervals not to exceed 18 months, until the 
requirements of paragraph (b) of this AD are accomplished.
    (2) If cracking is detected during any inspection required by 
this paragraph, prior to further flight, accomplish either paragraph 
(a)(2)(i) or (a)(2)(ii):
    (i) Replace the cracked bolt with a new bolt made of H-11 
material and continue to inspect in accordance with this paragraph 
at intervals not to exceed 18 months, until the requirements of 
paragraph (b) of this AD are accomplished. Or
    (ii) Replace the cracked bolt with a bolt made of Inconel, and 
replace the associated hardware, in accordance with the service 
bulletin. Such replacement constitutes terminating action for 
required ultrasonic inspections for that bolt.
    (b) Within 5 years after the effective date of this AD, replace 
all No.2 engine pylon lower spar forward mount and thrust link 
fitting attach bolts made of H-11 material, with bolts made of 
Inconel, and replace the associated hardware, in accordance with 
McDonnell Douglas DC-10 Service Bulletin 54-100, Revision 1, dated 
September 17, 1993. Such replacement constitutes terminating action 
for the inspections required by 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). 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.

    (d) Special flight permits may be issued in accordance with 
Federal Aviation Regulations (FAR) 21.197 and 21.199 to operate the 
airplane to a location where the requirements of this AD can be 
accomplished.
    (e) The inspections and replacement shall be done in accordance 
with McDonnell Douglas DC-10 Service Bulletin 54-100, Revision 1, 
dated September 17, 1993. 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, P.O. Box 1771, Long Beach, California 
90801-1771, Attention: Business Unit Manager, Technical 
Administrative Support, Dept. L51, Mail Code 2-98. Copies may be 
inspected at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane 
Directorate, Los Angeles Aircraft Certification Office, 3229 East 
Spring Street, Long Beach, California; or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.
    (f) This amendment becomes effective on March 24, 1994.

    Issued in Renton, Washington, on February 14, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-3754 Filed 2-18-94; 8:45 am]
BILLING CODE 4910-13-U