[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]
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