[Federal Register Volume 63, Number 249 (Tuesday, December 29, 1998)]
[Rules and Regulations]
[Pages 71575-71577]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-34095]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-288-AD; Amendment 39-10965; AD 98-26-22]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-10 Series 
Airplanes and 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 KC-10A (military) airplanes, that requires repetitive inspections 
to detect cracking of the lower cap of the wing rear spar, and repair, 
if necessary. For certain airplanes, this AD also provides for an 
optional terminating modification for the repetitive inspections. This 
amendment is prompted by reports of fatigue cracks found in the lower 
cap of the wing rear spar. The actions specified by this AD are 
intended to detect and correct fatigue cracking of the lower cap of the 
wing rear spar, which could result in reduced structural integrity of 
the airplane.

DATES: Effective February 2, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of February 2, 1999.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Aircraft Group, Long Beach Division, 
3855 Lakewood Boulevard, Long Beach, California 90846, Attention: 
Technical Publications Business Administration, Dept. 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, Transport Airplane Directorate, 
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: Ron Atmur, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA Transport Airplane Directorate, Los 
Angeles Aircraft Certification Office, 3960 Paramount Boulevard, 
Lakewood,

[[Page 71576]]

California 90712-4137; telephone (562) 627-5224; fax (562) 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 Series Airplanes and KC-10A (military) airplanes was published in 
the Federal Register on March 26, 1998 (63 FR 14654). That action 
proposed to require repetitive inspections to detect cracking of the 
lower cap of the wing rear spar, and repair, if necessary.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    Several commenters support the proposed rule.

Requests to Reference Latest Service Bulletins

    Several commenters request that the proposed AD be revised to 
reference Revision 01 of McDonnell Douglas Alert Service Bulletin DC10-
57A137, dated May 26, 1998, and McDonnell Douglas Service Bulletin 
DC10-57-138, dated May 28, 1998.
    These commenters state that Revision 01 of McDonnell Douglas Alert 
Service Bulletin DC10-57A137 contains new repair procedures and that 
McDonnell Douglas Service Bulletin DC10-57-138 contains an optional 
preventative modification. Without incorporation of this information, 
the commenters state that operators would have to seek approval from 
the FAA for alternative methods of compliance, which would create 
additional work for operators and the FAA.
    The FAA concurs with the commenters' requests to reference the 
latest service bulletins. Since issuance of the notice of proposed 
rulemaking (NPRM), the FAA has reviewed and approved the service 
bulletins mentioned by the commenters.
    The inspection procedures described in Revision 01 of McDonnell 
Douglas Alert Service Bulletin DC10-57A137 are identical to those 
described in the original version of that alert service bulletin (which 
was referenced in the proposed AD as the appropriate source of service 
information for accomplishment of the eddy current surface inspection). 
However, Revision 01 revises the original cracking conditions and adds 
new procedures for specific repairs. The FAA finds that accomplishment 
of these new repair procedures will maintain an adequate level of 
safety. Therefore, in lieu of accomplishing the required repair in 
accordance with a method approved by the FAA, operators can elect to 
accomplish the new subject repair. The FAA has revised paragraph (b) of 
the final rule accordingly.
    McDonnell Douglas Service Bulletin DC10-57-138 describes procedures 
for a preventative modification that would eliminate the need for 
certain repetitive inspections described in McDonnell Douglas Alert 
Service Bulletin DC10-57A137. The preventative modification involves 
the following:
    1. Removing affected taper-lok fasteners;
    2. Reaming holes to remove taper;
    3. Cold working affected holes;
    4. Performing an eddy current inspection using the open hole 
technique to detect cracks inside the holes, and repair, if necessary; 
and
    5. Installing new fasteners.
    The FAA finds that the preventative modification specified in that 
service bulletin may be provided as an optional terminating action for 
certain repetitive inspection requirements of the final rule. The FAA 
is not mandating the preventative modification of the rear spar lower 
cap for several reasons:
    1. Accessing the taper-lok fasteners of the lower cap of the wing 
rear spar for inspection is easily accomplished.
    2. The cracking of the spar emanating from the fastener holes is 
easily detectable by means of an eddy current surface inspection.
    3. The failure of a fastener may adversely affect the structural 
integrity of the airplane; however, the eddy current surface 
inspections will preclude the occurrence of multiple failed fasteners, 
which could result in a catastrophic failure.
    Therefore, for certain airplanes, the FAA has added a new paragraph 
(c) to the final rule to provide for this option, and has revised the 
cost impact information accordingly.

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 283 Model DC-10 Series Airplanes and KC-10A 
(military) airplanes of the affected design in the worldwide fleet. The 
FAA estimates that 201 airplanes of U.S. registry will be affected by 
this AD, that it will take approximately 8 work hours per airplane to 
accomplish the required inspection, 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 $96,480, or $480 per airplane, per 
inspection cycle.
    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.
    Should an operator elect to accomplish the optional terminating 
action rather than continue the repetitive inspections, it would take 
approximately 15 (for Group 1 airplanes) or 6 (for Group 2 airplanes) 
work hours per airplane to accomplish the modification, at an average 
labor rate of $60 per work hour. Required parts will cost approximately 
$3,546 per airplane (for Group 1 airplanes) and $2,145 per airplane 
(for Group 2 airplanes). Based on these figures, the cost impact of 
this optional terminating action is estimated to be $4,446 per airplane 
(for Group 1 airplanes) and $2,505 per airplane (for Group 2 
airplanes).

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.

[[Page 71577]]

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:

98-26-22   McDonnell Douglas: Amendment 39-10965. Docket 97-NM-288-
AD.

    Applicability: Model DC-10 series airplanes and KC-10A 
(military) airplanes, as listed in McDonnell Douglas Alert Service 
Bulletin DC10-57A137, dated July 31, 1997; 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 (d) 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 detect and correct fatigue cracking of the lower cap of the 
wing rear spar, which could result in reduced structural integrity 
of the airplane, accomplish the following:
    (a) Conduct an eddy current surface inspection to detect 
cracking of the lower cap of the wing rear spar, in accordance with 
the Accomplishment Instructions of McDonnell Douglas Alert Service 
Bulletin DC10-57A137, dated July 31, 1997, or Revision 01, dated May 
26, 1998; at the later of the times specified in paragraphs (a)(1) 
and (a)(2) of this AD. Thereafter, repeat this inspection at 
intervals not to exceed 1,500 landings, except as provided by 
paragraph (c) of this AD.
    (1) Prior to the accumulation of 7,000 total landings, or within 
18 months after the effective date of this AD, whichever occurs 
later. Or
    (2) Within 1,500 landings after the accomplishment of the 
inspection of Principal Structural Elements 57.10.007 and 57.10.008, 
in accordance with AD 95-23-09, amendment 39-9429.
    (b) If any crack is found during any inspection required by 
paragraph (a) of this AD, accomplish paragraph (b)(1) or (b)(2) of 
this AD, as applicable.
    (1) Except as provided by paragraph (c) of this AD, for any 
crack identified in Condition 2 or Condition 3 of McDonnell Douglas 
Alert Service Bulletin DC10-57A137, Revision 01, dated May 26, 1998: 
Prior to further flight, repair in accordance with a method approved 
by the Manager, Los Angeles Aircraft Certification Office (ACO), 
FAA, Transport Airplane Directorate; or accomplish the permanent 
repair of the spar cap in accordance with Revision 01 of the alert 
service bulletin, and repeat the eddy current surface inspection 
required by paragraph (a) of this AD thereafter at the times 
specified in Revision 01 of the alert service bulletin for that 
repaired spar cap.
    (2) For any crack identified in Condition 4 of McDonnell Douglas 
Alert Service Bulletin DC10-57A137, Revision 01, dated May 26, 1998: 
Accomplish either paragraph (b)(2)(i), or paragraphs (b)(2)(ii) and 
(b)(2)(iii) of this AD.
    (i) Prior to further flight, repair in accordance with a method 
approved by the Manager, Los Angeles Aircraft Certification Office 
(ACO), FAA, Transport Airplane Directorate.
    (ii) Prior to further flight, temporarily repair the spar cap in 
accordance with Revision 01 of the alert service bulletin. Repeat 
the eddy current surface inspection required by paragraph (a) of 
this AD thereafter at the applicable times specified in the alert 
service bulletin for that repaired spar cap, until accomplishment of 
paragraph (b)(3)(iii) of this AD.
    (iii) At the applicable time specified in the alert service 
bulletin, permanently repair the crack in accordance with Revision 
01 of the alert service bulletin. Accomplishment of the permanent 
repair constitutes terminating action for the repetitive eddy 
current surface inspection requirements of paragraph (b)(2)(ii) of 
this AD. Within 10,000 landings following accomplishment of the 
permanent repair, repeat the eddy current surface inspection 
required by paragraph (a) of this AD thereafter at the applicable 
times specified in Revision 01 of the alert service bulletin for 
that permanently repaired spar cap.
    (c) For airplanes on which no crack (Condition 1) or any crack 
that is specified in Condition 2 of McDonnell Douglas Alert Service 
Bulletin DC10-57A137, Revision 01, dated May 26, 1998, is detected: 
Accomplishment of the preventative modification specified in 
paragraphs (c)(1), (c)(2), (c)(3), (c)(4), (c)(5), and (c)(6) of 
this AD, in accordance with Revision 01 of the alert service 
bulletin, constitutes terminating action for the repetitive 
inspection requirements of paragraph (a) of this AD.
    (1) Remove existing sealant as required.
    (2) Remove affected taper-lok fasteners.
    (3) Ream holes to remove taper.
    (4) Cold work affected holes.
    (5) Perform an eddy current inspection using the open hole 
technique to detect cracks inside the holes. If any crack is 
detected, prior to further flight, repair in accordance with a 
method approved by Manager, Los Angeles ACO.
    (6) Install new fasteners.
    (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 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

    (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.
    (f) Certain actions shall be done in accordance with McDonnell 
Douglas Alert Service Bulletin DC10-57A137, dated July 31, 1997, or 
McDonnell Douglas Alert Service Bulletin DC10-57A137, Revision 01, 
dated May 26, 1998. 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 Boeing 
Commercial Aircraft Group, Long Beach Division, 3855 Lakewood 
Boulevard, Long Beach, California 90846, Attention: Technical 
Publications Business Administration, Dept. C1-L51 (2-60). 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, 
3960 Paramount Boulevard, Lakewood, California; or at the Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.
    (g) This amendment becomes effective on February 2, 1999.

    Issued in Renton, Washington, on December 17, 1998.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-34095 Filed 12-28-98; 8:45 am]
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