AD 2000-20-09

[Federal Register Volume 65, Number 195 (Friday, October 6, 2000)]
[Rules and Regulations]
[Pages 59703-59705]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 00-25433]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-308-AD; Amendment 39-11920; AD 2000-20-09]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 757 Series Airplanes 
Powered by Pratt & Whitney Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Boeing Model 757 series airplanes, that requires 
modification of the nacelle strut and wing structure. This amendment is 
prompted by reports indicating that the actual operational loads 
applied to the nacelle are higher than the analytical loads that were 
used during the initial design. Such an increase in loading can lead to 
fatigue cracking in primary strut structure prior to an airplane 
reaching its design service objective. The actions specified by this AD 
are intended to prevent fatigue cracking in primary strut structure and 
consequent reduced structural integrity of the strut.

DATES: Effective November 13, 2000.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of November 13, 2000.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. 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 Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

FOR FURTHER INFORMATION CONTACT: Dennis Stremick, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2776; fax (425) 227-1181.

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 Boeing Model 757 series 
airplanes was published in the Federal Register on June 7, 2000 (65 FR 
36095). That action proposed to require modification of the nacelle 
strut and wing structure.

Comments

    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 proposed rule.
    One commenter states that it does not operate Boeing Model 757 
series airplanes powered by Pratt & Whitney engines and is not affected 
by the proposed rule.

Contact Manufacturer for Approval of Repairs

    One commenter states that the instructions specified in paragraph 
(c) of the proposal do not clearly identify who should be contacted if 
any damage to the airplane structure is found during accomplishment of 
the modification referenced in the proposal. The commenter states that, 
based on instructions in Boeing Service Bulletin 757-54-0034, and the 
fact that the manufacturer is more knowledgeable about the 
modifications necessary; paragraph (c) should be revised to include 
contacting the manufacturer for repair of any damage.
    The FAA concurs with the commenter's request, however, although 
Boeing Service Bulletin 757-54-0034 specifies that the manufacturer may 
be contacted for disposition of certain damage conditions, this AD 
requires the repair of those conditions to be accomplished in 
accordance with a method approved by the Manager, Seattle Aircraft 
Certification Office

[[Page 59704]]

(ACO), FAA, or data meeting the type certification basis of the 
airplane approved by a Boeing Company Designated Engineering 
Representative (DER) who has been authorized by the FAA to make such 
findings. Paragraph (c) of this final rule has been revised to add 
Boeing DER approval for repairs.

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 317 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 278 airplanes of U.S. registry 
will be affected by this AD.
    It will take approximately 800 work hours per airplane to 
accomplish the required modification of the nacelle strut and wing 
structure described in Boeing Service Bulletin 757-54-0034, at an 
average labor rate of $60 per work hour. Required parts will be 
provided at no cost by the airplane manufacturer. Based on these 
figures, the cost impact of this required modification on U.S. 
operators is estimated to be $13,344,000, or $48,000 per airplane.
    It will take approximately 26 work hours per airplane to accomplish 
the actions described in Boeing Service Bulletin 757-54-0027, Revision 
1, at an average labor rate of $60 per work hour. Required parts will 
be provided at no cost by the airplane manufacturer. Based on these 
figures, the cost impact of these required actions on U.S. operators is 
estimated to be $433,680, or $1,560 per airplane.
    It will take approximately 90 work hours per airplane to accomplish 
the actions described in Boeing Service Bulletin 757-54-0036, at an 
average labor rate of $60 per work hour. Required parts will be 
provided at no cost by the airplane manufacturer. Based on these 
figures, the cost impact of these required actions on U.S. operators is 
estimated to be $1,501,200, or $5,400 per airplane.
    The 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 cost impact figures discussed 
in AD rulemaking actions represent only the time necessary to perform 
the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

Regulatory Impact

    The regulations adopted herein will not have a substantial direct 
effect 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, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    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.


Sec. 39.13  [Amended]

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

2000-20-09  Boeing: Amendment 39-11920. Docket 99-NM-308-AD.

    Applicability: Model 757 series airplanes powered by Pratt & 
Whitney engines, line numbers 1 through 735 inclusive, 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 prevent fatigue cracking in primary strut structure and 
consequent reduced structural integrity of the strut, accomplish the 
following:

Modifications

    (a) Modify the nacelle strut and wing structure on both the left 
and right sides of the airplane, in accordance with Boeing Service 
Bulletin 757-54-0034, dated May 14, 1998, at the later of the times 
specified in paragraph (a)(1) or (a)(2) of this AD.
    (1) Prior to the accumulation of 37,500 total flight cycles, or 
within 20 years since the date of manufacture, whichever occurs 
first. Use of the optional threshold formula described in paragraph 
I.D. of the service bulletin is an acceptable alternative to the 20-
year threshold.
    (2) Within 3,000 flight cycles after the effective date of this 
AD.
    (b) Prior to or concurrently with the accomplishment of the 
modification of the nacelle strut and wing structure required by 
paragraph (a) of this AD; as specified in paragraph I.D., Table I, 
``Strut Improvement Bulletins,'' on page 5 of Boeing Service 
Bulletin 757-54-0034, dated May 14, 1998; accomplish the actions 
specified in Boeing Service Bulletin 757-54-0027, Revision 1, dated 
October 27, 1994, and Boeing Service Bulletin 757-54-0036, dated May 
14, 1998, as applicable, in accordance with those service bulletins.

Repair

    (c) If any damage to airplane structure is found during the 
accomplishment of the modification required by paragraph (a) of this 
AD; and the service bulletin specifies to contact Boeing for 
appropriate action: Prior to further flight, repair in accordance 
with a method approved by the Manager, Seattle Aircraft 
Certification Office (ACO), FAA; or in accordance with data meeting 
the type certification basis of the airplane approved by a Boeing 
Company Designated Engineering Representative (DER) who has been 
authorized by the Manager, Seattle ACO, to make such findings. For a 
repair method to be approved by the Manager, Seattle ACO, as 
required by this paragraph, the approval letter must specifically 
reference this AD.

Alternative Methods of Compliance

    (d) An alternative method of compliance or adjustment of the 
compliance time that

[[Page 59705]]

provides an acceptable level of safety may be used if approved by 
the Manager, Seattle ACO. Operators shall submit their requests 
through an appropriate FAA Principal Maintenance Inspector, who may 
add comments and then send it to the Manager, Seattle ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (e) Special flight permits may be issued in accordance with 
Secs. 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.

Incorporation by Reference

    (f) Except as provided by paragraph (c) of this AD, the actions 
shall be done in accordance with Boeing Service Bulletin 757-54-
0034, dated May 14, 1998; Boeing Service Bulletin 757-54-0027, 
Revision 1, dated October 27, 1994; and Boeing Service Bulletin 757-
54-0036, dated May 14, 1998; as applicable. 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 Airplane Group, P.O. Box 3707, 
Seattle, Washington 98124-2207. Copies may be inspected at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.

Effective Date

    (g) This amendment becomes effective on November 13, 2000.

    Issued in Renton, Washington, on September 28, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-25433 Filed 10-5-00; 8:45 am]
BILLING CODE 4910-13-U