[Federal Register Volume 68, Number 117 (Wednesday, June 18, 2003)]
[Proposed Rules]
[Pages 36499-36502]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-15336]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-370-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to certain Boeing Model 757 
series airplanes, that currently requires modification of the nacelle 
strut and wing structure. This action would reduce a certain compliance 
time in the existing AD. The actions specified by the proposed AD are 
intended to prevent fatigue cracking in primary strut structure and 
consequent reduced structural integrity of the strut. This action is 
intended to address the identified unsafe condition.

DATES: Comments must be received by August 4, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-370-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2001-NM-370-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the

[[Page 36500]]

Internet as attached electronic files must be formatted in Microsoft 
Word 97 for Windows or ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplane Group, PO Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

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) 
917-6450; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this action may be changed in 
light of the comments received.
    Submit comments using the following format:
    [sbull] Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] Include justification (e.g., reasons or data) for each 
request.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2001-NM-370-AD.'' The postcard will be date stamped 
and returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 2001-NM-370-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On September 28, 2000, the FAA issued AD 2000-20-09, amendment 39-
11920 (65 FR 59703, October 6, 2000), applicable to certain Boeing 
Model 757 series airplanes, that requires modification of the nacelle 
strut and wing structure. The requirements of that AD are intended to 
prevent fatigue cracking in primary strut structure and consequent 
reduced structural integrity of the strut.

Actions Since Issuance of Previous Rule

    Since the issuance of AD 2000-20-09, the airplane manufacturer has 
done a new structural reassessment of the upper link of the strut of 
Boeing Model 757 series airplanes powered by Pratt & Whitney engines. 
This reassessment indicates that certain design changes are needed on 
the upper link to ensure that fatigue cracking does not occur on the 
primary strut structure before an airplane reaches its design service 
objective of 20 years, or 50,000 flight cycles. Analysis indicates that 
such cracking, if it were to occur, would grow at a much greater rate 
than originally expected. Fatigue cracking in primary strut structure 
would result in reduced structural integrity of the strut.
    The compliance time for the modification of the upper link (Boeing 
Service Bulletin 757-54-0036, dated May 14, 1998) required by paragraph 
(b) of AD 2000-20-09, has been reduced due to this new structural 
assessment.

Explanation of New Relevant Service Information

    We have reviewed and approved Boeing Service Bulletin 757-54-0034, 
Revision 1, dated October 11, 2001. (Boeing Service Bulletin 757-54-
0034, dated May 14, 1998, was referenced as the appropriate source of 
service information for the actions required by paragraph (a) of AD 
2000-20-09.) We find that the changes incorporated in Revision 1 of the 
service bulletin are not substantive, meaning that airplanes modified 
per the original issue of the service bulletin are not subject to any 
additional work under Revision 1 of the service bulletin. Therefore, we 
have added Revision 1 of the service bulletin as another source of 
service information for the accomplishment of the modification required 
by paragraph (a) of this AD.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would supersede AD 2000-20-09 to continue to require 
modification of the nacelle strut and wing structure. This new action 
proposes to reduce a certain compliance time in the existing AD. The 
actions would be required to be accomplished in accordance with the 
service bulletins described previously, and as discussed below.

Difference Between This Proposed AD and Service Bulletin 757-54-0036

    This proposed AD would add a grace period of 2 years to the 
thresholds recommended in the service bulletin for accomplishment of 
the modification of the upper link and wire support bracket of the 
strut, as specified in paragraph (d) of this AD, as follows: Prior to 
the accumulation of 27,000 total flight cycles (for Model 757-200 
series airplanes) or 29,000 total flight cycles (for Model 757-200PF 
series airplanes), or within 2 years after the effective date of this 
AD, whichever is later.

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 
would be affected by this proposed AD. Since this proposed AD would 
merely reduce the compliance time for certain actions required by AD 
2000-20-09 (Service Bulletin 757-54-0036), it would add no additional 
costs, and would require no additional work to be performed by affected 
operators. The current costs associated with AD 2000-20-09 are 
reiterated in their entirety (as follows) for the convenience of 
affected operators:
    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.

[[Page 36501]]

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 current or proposed 
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 proposed herein would 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 proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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 removing amendment 39-11920 (65 FR 
59703, October 6, 2000), and by adding a new airworthiness directive 
(AD), to read as follows:

Boeing: Docket 2001-NM-370-AD. Supersedes AD 2000-20-09, Amendment 
39-11920.

    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 (e) 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:

Restatement of Requirements of AD 2000-20-09:

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; or Revision 1, dated 
October 11, 2001; 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 November 13, 2000 (the 
effective date of AD 2000-20-09, amendment 39-11920).
    (b) Except as provided by paragraph (d) of this AD: 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.

New Requirements of this AD:

Modification

    (d) Modify the nacelle strut (includes replacing the upper link 
with a new, improved part and modifying the wire support bracket 
attached to the upper link) in accordance with Boeing Service 
Bulletin 757-54-0036, dated May 14, 1998, at the earlier of the 
times specified in paragraph (d)(1) or (d)(2) of this AD.
    (1) Prior to or concurrently with accomplishment of the 
modification of the nacelle strut and wing structure required by 
paragraph (a) of this AD.
    (2) Prior to the accumulation of 27,000 total flight cycles (for 
Model 757-200 series airplanes) or 29,000 total flight cycles (for 
Model 757-200PF series airplanes), or within 2 years after the 
effective date of this AD, whichever is later.

Alternative Methods of Compliance

    (e) 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, 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

    (f) 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.


[[Page 36502]]


    Issued in Renton, Washington, on June 12, 2003.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-15336 Filed 6-17-03; 8:45 am]
BILLING CODE 4910-13-P