[Federal Register Volume 61, Number 96 (Thursday, May 16, 1996)]
[Rules and Regulations]
[Pages 24688-24690]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-12147]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-108-AD; Amendment 39-9624; AD 96-10-17]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-10-10, -15, 
and, -30 Series Airplanes and KC-10 (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-10-10, -15, and -30 
series airplanes and KC-10A (military) airplanes, that requires 
inspections to detect cracks of the upper aft mating bolt hole of the 
wing pylon truss fittings, and various follow-on actions. This 
amendment is prompted by reports of cracks found in the upper aft 
mating bolt hole of the wing pylon truss fitting located near the 
engine forward mount on Model DC-10-30 series airplanes, which were 
caused by fatigue-related stress. The actions specified by this AD are 
intended to prevent fatigue-related cracking, which could lead to 
failure of the fitting, separation of a portion of the engine forward 
mount truss from the pylon, and consequent separation of the engine 
from the airplane.

DATES: Effective June 20, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 20, 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, 
Transport Airplane Directorate, 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: Maureen Moreland, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone 
(310) 627-5238; 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-10-10, -15, and -30 series airplanes and KC-10A (military) airplanes 
was published in the Federal Register on September 27, 1995 (60 FR 
49809). That action proposed to require repetitive ultrasonic or eddy 
current inspections to detect cracks of the upper aft mating bolt hole 
of the wing pylon truss fittings, 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

    Two commenters support the proposed rule.

Request for Extension of Compliance Time for Initial Inspection

    One commenter requests that the compliance time for the initial 
inspection be extended from the proposed 1,000 landings to 1,200 
landings for Model DC-10-30 series airplanes. The commenter states such 
a compliance time would follow the recommendations of McDonnell Douglas 
DC-10 Service Bulletin 54-108, dated February 9, 1995. The commenter 
also questions what data or analysis the FAA used to justify shortening 
the threshold to 1,000 landings.
    The FAA does not agree with the commenter's request to extend the 
compliance time. The FAA points out that 1,000 landings is not the 
inspection ``threshold,'' but a ``grace period'' that was established 
to preclude unnecessarily grounding airplanes that have exceeded the 
10,000-landing threshold or will exceed it within 1,000 landings. In 
determining the appropriate ``grace period'' for this action, the FAA 
not only considered the degree of urgency associated with addressing 
the unsafe condition, but the amount of time necessary for operators to 
accomplish the required inspection and other factors affecting the 
ability of the operators to comply. In light of all these factors, the 
FAA finds the 1,000 landing ``grace period'' for initiating the 
required inspections to be warranted, in that it represents an 
appropriate interval of time allowable for affected airplanes to 
continue to operate without compromising safety.

Clarification of Requirements for Type of Inspection

    One commenter points out that proposed paragraphs (a) and (b) 
indicate that operators are to perform either ultrasonic or eddy 
current inspections to detect the subject cracking. However, the 
commenter states that the initial and repetitive eddy current 
inspections are not an option if the upper aft and/or middle mating 
bolt hole(s) have bushings installed from previous rework, in 
accordance with McDonnell Douglas DC-10 Service Bulletin 54-108, dated 
February 9, 1995.
    The FAA finds that clarification of this point is necessary. As 
paragraphs (a) and (b) of the proposed rule were worded, operators 
could incorrectly interpret the requirements as meaning that they have 
a choice between performing an ultrasonic inspection or an eddy current 
inspection for all configurations of the bolt holes. However, the 
intent of those requirements was to require operators to perform either 
an ultrasonic inspection or an eddy current inspection, as appropriate, 
depending upon the configuration of the subject area and as specified 
in the service bulletin. Therefore, the commenter is correct in noting 
that, for airplanes on which the upper aft and middle mating bolt holes 
have bushings installed from previous rework (Condition 2), operators 
must accomplish the inspection by using only the ultrasonic method. In 
light of this, the FAA has revised the wording of paragraphs (a) and 
(b) of the final rule to clarify this.

Clarification of Requirements for Repetitive Inspections

    The same commenter asks if the repetitive ultrasonic inspection 
intervals

[[Page 24689]]

are the same for bolt hole(s) that have bushings installed from 
previous rework as well as for bolt hole(s) that do not have bushings 
installed.
    The FAA finds that clarification of this point is necessary. The 
FAA points out that, for certain Model DC-10-15, and -30 series 
airplanes, and KC-10A (military) airplanes, Service Bulletin 54-108 
recommends that the compliance time for the repetitive ultrasonic 
inspections be accomplished at intervals of 4,000 landings if the bolts 
holes have bushings installed, and at intervals of 5,000 landings if 
the bolt holes do not have bushings installed. However, for those 
airplanes, paragraph (b)(1)(i) of the final rule differs from the 
recommendations of the service bulletin in that it requires a 
compliance time interval of 5,000 landings, whether or not the bolt 
holes have bushings installed. In developing an appropriate compliance 
time for that action, the FAA, along with McDonnell Douglas, reviewed 
the damage tolerance analysis of the bolt hole, and determined that the 
compliance time of 5,000 landings will not adversely affect safety. 
McDonnell Douglas is planning to revise Service Bulletin 54-108 in the 
future to be consistent with this AD

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 changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    There are approximately 376 McDonnell Douglas Model DC-10-10, -15, 
and -30 series airplanes and KC-10 (military) airplanes of the affected 
design in the worldwide fleet. The FAA estimates that 228 airplanes of 
U.S. registry will be affected by this AD, that it will take 
approximately 5 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 $68,400, or $300 per airplane, per inspection.
    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.

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 USC 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

96-10-17  McDonnell Douglass: Amendment 39-9624, Docket 95-NM-108-
AD.

    Applicability: Model DC-10-10, -15, and -30 series airplanes and 
KC-10A (military) airplanes; as listed in McDonnell Douglas DC-10 
Service Bulletin 54-108, dated February 9, 1995; 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 (c) of 
this AD. The request should include an assessment of the effect of 
the modficiation, 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: Requried as indicated, unless accomplished 
previously.
    To prevent fatigue-related cracking, which could lead to failure 
of the pylon truss fitting, separation of a portion of the engine 
from the airplane, accomplish the following:
    (a) For Model DC-10-15, and -30 series airplanes and KC-10A 
(military) airplanes: Prior to the accumulation of 10,000 total 
landings on the pylon truss fitting or within 1,000 landings on the 
pylon truss fitting after the effective date of this AD, whichever 
occurs later, perform either an ultrasonic inspection or an eddy 
current inspection, as applicable, to detect cracks of the upper aft 
mating bolt hole of the wing pylon truss fittings, in accordance 
with McDonnell Douglas DC-10 Service Bulletin 54-108, dated February 
9, 1995.
    (1) If no cracks are detected, repeat the inspections in 
accordance with paragraph (a)(1)(i) or (a)(1)(ii), as applicable:
    (i) If inspecting using ultrasonic techniques repeat inspection 
at intervals not to exceed 5,000 landings.
    (ii) If inspection using eddy current techniques, repeat 
inspection at intervals not to exceed 8,000 landings.
    (2) Accomplishment of the actions specified in paragraphs 
(a)(2)(i), (a)(2)(ii), and (a)(2)(iii) constitutes terminating 
action for the repetitive inspections required by paragraph (a)(1) 
of this AD:
    (i) Accomplish the preventative modification in accordance with 
Condition 1 (bushing not installed), Option III. or Condition 2 
(bushing installed), Option II, of the service bulletin, as 
applicable. And
    (ii) Prior to the accumulation of 10,000 total landings on the 
pylon truss fitting following accomplishment of the modification, 
perform an ultrasonic inspection to detect cracks of the upper aft 
mating bolt hole of the wing pylon truss fittings, in accordance 
with the service bulletin. And
    (iii) Thereafter, repeat the ultrasonic inspection at intervals 
not to exceed 5,000 landings on the pylon truss fitting.
    (3) If any crack is found in the pylon truss fitting during any 
inspection required by this paragraph, prior to further flight, 
repair it in accordance with the service bulletin. At the times 
specified in the service bulletin, perform follow-on actions in 
accordance with the service bulletin. In all cases, where the 
service bulletin indicates ``contact Douglas for disposition,'' the 
repair must be accomplished in accordance with a method approved by 
the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, 
Transport Airplane Directorate.
    (b) For Model DC-10-10 series airplanes: Prior to the 
accumulation of 17,000 total landings on the pylon truss fitting or 
within 1,500 landings on the pylon truss fitting after

[[Page 24690]]

the effective date of this AD, whichever occurs later, perform 
either an ultrasonic inspection or an eddy current inspection, as 
applicable, to detect cracks of the upper aft mating bolt hole of 
the wing pylon truss fittings, in accordance with McDonnell Douglas 
DC-10 Service Bulletin 54-108, dated February 9, 1995.
    (1) If no cracks are detected, repeat the inspections in 
accordance with paragraph (b)(1)(i) or (b)(1)(ii), as applicable:
    (i) If inspecting using ultrasonic techniques, repeat the 
inspection at intervals not to exceed 10,000 landings.
    (ii) If inspecting using eddy current techniques, repeat the 
inspection at intervals not to exceed 15,000 landings.
    (2) Accomplishment of the actions specified in paragraphs 
(b)(2)(i), (b)(2)(ii), and (b)(2)(iii) constitutes terminating 
action for the repetitive inspections required by paragraph (b)(1) 
of this AD:
    (i) Accomplish the preventative modification in accordance with 
Condition 1 (bushing not installed), Option III, or Condition 2 
(bushing installed), Option II, of the service bulletin, as 
applicable. And
    (ii) Prior to the accumulation of 18,000 total landings on the 
pylon truss fitting following accomplishment of the modification, 
perform an ultrasonic inspection to detect cracks of the upper aft 
mating bolt hole of the wing pylon truss fittings, in accordance 
with the service bulletin. And
    (iii) Thereafter, repeat the ultrasonic inspection at intervals 
not to exceed 10,000 landings on the pylon truss fitting.
    (3) If any crack is found in the pylon truss fitting during any 
inspection required by this paragraph, prior to further flight, 
repair it in accordance with the service bulletin. At the times 
specified in the service bulletin, perform follow-on actions in 
accordance with the service bulletin. In all cases, where the 
service bulletin indicates ``contact Douglas for disposition,'' the 
repair must be accomplished in accordance with a method approved by 
the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, 
Transport Airplane Directorate.
    (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.
    (e) The actions shall be done in accordance with McDonnell 
Douglas DC-10 Service Bulletin 54-108, dated February 9, 1995. 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, Transport Airplane 
Directorate, 3960 Paramount Boulevard, Lakewood, California; or at 
the Office of the Federal Register, 800 North Capitol Street, NW., 
suite 700, Washington, DC.
    (f) This amendment becomes effective on June 20, 1996.

    Issued in Renton, Washington, on May 9, 1996.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-12147 Filed 5-15-96; 8:45 am]
BILLING CODE 4910-13-M