[Federal Register Volume 61, Number 104 (Wednesday, May 29, 1996)]
[Rules and Regulations]
[Pages 26778-26780]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-13231]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-145-AD; Amendment 39-9636; AD 96-11-11]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-9 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to all McDonnell Douglas Model DC-9 series airplanes, that 
requires inspection(s) to detect cracking in the nose skin of the 
fuselage, and various follow-on actions. This amendment also provides 
for an optional modification, which would defer certain repetitive 
inspections, if no cracking is detected. This amendment is prompted by 
reports of cracking in the upper nose skin of the fuselage due to 
fatigue. The actions specified by this AD are intended to prevent 
fatigue-related cracking, which could compromise the structural 
integrity of the airplane.

DATES: Effective July 3, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 3, 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: Ron Atmur, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone 
(310) 627-5224; 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 all McDonnell Douglas Model DC-9 
series airplanes was published in the Federal Register on January 19, 
1996 (61 FR 1301). That action proposed to require inspection(s) to 
detect cracking in the nose skin of the fuselage, and various follow-on 
actions. That action also proposed a provision for an optional 
modification, which would defer certain repetitive inspections, if no 
cracking is detected.
    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 to Extend the Compliance Time

    One commenter requests that the ``grace period'' of the compliance 
time for the accomplishment of the high frequency eddy current (HFEC) 
inspection be extended from the proposed 3,000 landings to 4,000 
landings. This will allow the HFEC

[[Page 26779]]

inspection to be accomplished during a regularly scheduled maintenance 
check, thereby eliminating any additional expenses. In addition, the 
commenter indicates that it has accomplished the HFEC inspection on 86 
Model DC-9 series airplanes and has found ``a high rate of positive 
findings'' (i.e., cracking).
    The FAA does not concur with the commenter's request to extend the 
``grace period'' of the compliance time. In developing an appropriate 
compliance time for this action, the FAA considered the safety 
implications, parts availability, and normal maintenance schedules for 
timely accomplishment of the HFEC inspection. In consideration of these 
items, as well as the numerous reports of cracking in the upper nose 
skin of the fuselage of airplanes in service, the FAA has determined 
that a ``grace period'' of 3,000 landings, as proposed, is appropriate. 
However, under the provisions of paragraph (b) of the final rule, the 
FAA may approve requests for adjustments to the compliance time if data 
are submitted to substantiate that such an adjustment would provide an 
acceptable level of safety.

Request to Allow DER Approval of Repairs

    This commenter also requests that proposed paragraph (a)(3) be 
revised to permit the approval of repairs (of any cracked areas beyond 
the repair limits specified in McDonnell Douglas DC-9 Service Bulletin 
53-262) by Designated Engineering Representatives (DER) of the 
McDonnell Douglas Corporation; this will allow a more expeditious 
response time on repair recommendations.
    The FAA does not concur with the commenter's request to revise 
paragraph (a)(3) of this AD. While DER's are authorized to determine 
whether a design or repair method complies with a specific requirement, 
they are not authorized to make the discretionary determination as to 
what the applicable requirement is. Further, where repair data does not 
exist, it is essential that the FAA have feedback as to the type of 
repairs being made. The FAA has determined that the Manager of the Los 
Angeles Aircraft Certification Office (ACO) should approve any such 
repairs or other deviations to the AD's requirements. Given that 
possible new relevant issues might be revealed during this process, it 
is imperative that the FAA, at this level, have such feedback. Only by 
reviewing deviation approvals can the FAA be assured of this feedback 
and of the adequacy of the repair methods. However, the FAA, in 
conjunction with the Aviation Rulemaking Advisory Committee (ARAC) 
currently is considering guidelines to address this issue, and may 
eventually develop additional FAA policy on this subject.

Request to Allow a Temporary Repair

    One commenter requests that the FAA revise the proposal to allow a 
temporary repair, having a life limit of 8,000 flight cycles, to be 
accomplished in accordance with Structural Repair Manual 53-04, Figure 
12B, Class III, until the proposed permanent repair can be 
accomplished. This would minimize down time for the operator.
    The FAA does not concur. The FAA does not consider it appropriate 
to include various provisions in an AD applicable to a single 
operator's unique use of an affected airplane. Paragraph (b) of this AD 
provides for the approval of alternative methods of compliance to 
address these types of unique circumstances.

Request for Clarification of Use of Previously Approved Repairs

    One commenter requests clarification as to the use of repairs that 
have been previously approved by the Manager, Los Angeles ACO, in 
accordance with AD 94-03-01, amendment 39-8907 (59 FR 6538, February 
11, 1994).
    The FAA agrees that clarification is necessary. The FAA considers 
the subject area of this AD to be identical to the subject area in AD 
94-03-01. Therefore, repairs that have been approved previously by the 
Manager, Los Angeles ACO, are considered to be approved as alternative 
methods of compliance with paragraphs (a)(2) and (a)(3) of this AD. 
Accordingly, the FAA has revised the final rule to include a new 
paragraph (b)(2) to clarify this.

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

Cost Impact

    There are approximately 889 Model DC-9 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 568 
airplanes of U.S. registry will be affected by this AD, that it will 
take approximately 10 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 $340,800, or $600 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. However, since the issuance of the 
proposal, the FAA has been advised that the initial inspection required 
by this AD has been accomplished on at least 86 affected airplanes. 
Therefore, the future cost impact of this AD on U.S. operators is 
reduced by approximately $51,600.

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 U.S.C. 106(g), 40113, 44701.

[[Page 26780]]

Sec. 39.13  [Amended]

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

96-11-11  McDonnell Douglas: Amendment 39-9636. Docket 95-NM-145-AD.

    Applicability: All Model DC-9-10, -20, -30, -40, -50, and C-9 
(military) series airplanes, 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 (b)(1) 
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 prevent fatigue-related cracking, which could compromise the 
structural integrity of the airplane, accomplish the following:
    (a) Prior to the accumulation of 40,000 total landings, or 
within 3,000 landings after the effective date of this AD, whichever 
occurs later, perform a high frequency eddy current (HFEC) 
inspection to detect cracking in the nose skin of the fuselage, in 
accordance with McDonnell Douglas DC-9 Service Bulletin 53-262, 
dated October 11, 1994.
    (1) If no cracking is detected, accomplish either paragraph 
(a)(1)(i) or (a)(1)(ii) of this AD, in accordance with the service 
bulletin.
    (i) Repeat the HFEC inspection thereafter at intervals not to 
exceed 4,000 landings; or
    (ii) Accomplish the modification of the upper nose skin of the 
cockpit fuselage in accordance with the service bulletin. Prior to 
the accumulation of 60,000 landings after accomplishment of this 
modification, perform a visual inspection of the upper nose skin of 
the cockpit fuselage in accordance with the service bulletin. Repeat 
the visual inspection thereafter at intervals not to exceed 25,000 
landings.
    (2) If any cracking is detected and it is within the repair 
limits specified in the service bulletin, prior to further flight, 
repair the cracked nose skin in accordance with the service 
bulletin. Prior to the accumulation of 60,000 landings after 
accomplishment of this repair, perform a visual inspection to detect 
cracking of the repair; and prior to further flight, repair any 
cracking found during this inspection; in accordance with a method 
approved by the Manager, Los Angeles Aircraft Certification Office 
(ACO), FAA, Transport Airplane Directorate.
    (3) If any cracking is detected and it is beyond the repair 
limits specified in the service bulletin, prior to further flight, 
repair the cracked nose skin in accordance with a method approved by 
the Manager, Los Angeles ACO.
    (b)(1) 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.

    (b)(2) Alternative methods of compliance, approved in accordance 
with AD 94-03-01, amendment 39-8907, are approved as alternative 
methods of compliance with paragraphs (a)(2) and (a)(3) of this AD. 
This approval only applies to repairs that are subject to the 
requirements of this AD.
    (c) 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.
    (d) The inspections, modification, and certain repairs shall be 
done in accordance with McDonnell Douglas DC-9 Service Bulletin 53-
262, dated October 11, 1994. 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.
    (e) This amendment becomes effective on July 3, 1996.

    Issued in Renton, Washington, on May 20, 1996.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-13231 Filed 5-28-96; 8:45 am]
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