[Federal Register: April 15, 2003 (Volume 68, Number 72)]
[Proposed Rules]
[Page 18170-18173]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr15ap03-29]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2000-NM-376-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 757 Series Airplanes
Equipped With Rolls Royce RB211 Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Supplemental notice of proposed rulemaking; reopening of
comment period.
-----------------------------------------------------------------------
SUMMARY: This document revises an earlier proposed airworthiness
directive (AD), applicable to certain Boeing Model 757 series airplanes
equipped with Rolls Royce RB211 engines, that would have superseded an
existing AD that currently requires modification of the nacelle strut
and wing structure. The proposed AD would have added a one-time
inspection of the middle gusset of the inboard side load fitting for
proper alignment, and a one-time inspection of certain fastener holes
in the lower spar fitting of the nacelle strut and wing structure for
cracking, and corrective actions, if necessary. For certain airplanes,
the proposed AD would have required installation of new fasteners. This
new action revises the proposed rule by reducing a certain compliance
time and adding new inspections. The actions specified by this new
proposed AD are intended to prevent fatigue cracking in primary strut
structure and consequent reduced structural integrity of the strut.
These actions are intended to address the identified unsafe condition.
DATES: Comments must be received by May 12, 2003.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 2000-NM-376-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:
9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must
contain ``Docket No. 2000-NM-376-AD'' in the subject line and need not
be submitted in triplicate. Comments sent via the 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, P.O. 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 2000-NM-376-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. 2000-NM-376-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
A proposal to amend part 39 of the Federal Aviation Regulations (14
CFR part 39) to add an airworthiness directive (AD), applicable to
certain Boeing Model 757 series airplanes equipped with Rolls Royce
RB211 engines, was published as a notice of proposed rulemaking (NPRM)
in the Federal Register on January 4, 2002 (67 FR 547). That NPRM
proposed to supersede AD 99-24-07, amendment 39-11431 (64 FR 66370,
November 26, 1999), which is applicable to certain Boeing Model 757
series airplanes equipped with Rolls Royce RB211 engines. That NPRM
would have continued to require modification of the nacelle strut and
wing structure. That NPRM would also have added a one-time inspection
of the middle gusset of the inboard side load fitting for proper
alignment, and a one-time inspection of certain fastener holes in the
lower spar fitting of the nacelle strut and wing structure for
cracking, and corrective actions, if necessary. For certain airplanes,
that NPRM would have required installation of new fasteners. Fatigue
cracking in primary strut structure could result in reduced structural
integrity of the strut.
Actions Since Issuance of Previous Proposal
Since the issuance of that NPRM, the FAA has reviewed and approved
Boeing Service Bulletin 757-54-0035, Revision 2, dated June 13, 2002,
including Evaluation Form. The procedures in this service bulletin are
similar to those in Boeing Service Bulletin 757-54-0035, Revision 1,
dated April 15, 1999, which was referenced as the appropriate source of
service information for the actions required by the original NPRM.
However, Revision 2 reduces the compliance time for the detailed
inspection of the middle gusset for airplanes that have not yet
accumulated 50,000 total flight cycles. The new compliance time for the
inspection is before the accumulation of 50,000 total
[[Page 18171]]
flight cycles or within 15,000 flight cycles after doing the
modification required by AD 99-24-07, whichever is earlier.
Comments
Due consideration has been given to the comments received in
response to the NPRM. One commenter has no technical objection to the
NPRM, but does not agree that the proposed inspections are necessary to
ensure the continued airworthiness of the engine strut. Another
commenter does not own or operate the affected airplanes.
Request To Change Paragraph (b)
One commenter, the manufacturer, states that there are airplanes in
service that are many years away from the compliance threshold for the
inspections specified in paragraph (b) of the NPRM. The commenter adds
that those airplanes will not receive timely inspections of the lower
spar fitting/aft bulkhead fasteners within the compliance time of
15,000 total flight cycles or 6 months after the effective date of the
AD, whichever is later, as specified in paragraph (b). The commenter
asks that paragraph (b) be changed to reduce the compliance time for
those airplanes in order to ensure that the inspections are done in a
timely manner.
We agree with the commenter. The manufacturer has provided data
which show that the compliance time specified in Revision 1 of the
service bulletin is not adequate to preclude an unsafe condition of
loose or missing fasteners in the aft bulkhead of the lower spar
fitting before the airplane reaches 50,000 total flight cycles. Also,
we have approved Revision 2 of the referenced service bulletin, as
stated above, in which the manufacturer recommends reducing the
compliance time for airplanes that have not yet accumulated 50,000
total flight cycles. We have added a detailed inspection for loose or
missing fasteners, and reduced the compliance time for the inspection
specified in Revision 2 of the service bulletin (before the
accumulation of 50,000 total flight cycles or within 15,000 flight
cycles after doing the modification, whichever is first) to specify the
compliance time as ``before the accumulation of 15,000 total flight
cycles or within 6 months after the effective date of the AD, whichever
is first.''
Request To Delete the Word ``Midchord''
One commenter asks that all references to the word ``midchord'' be
deleted from the NPRM. The commenter notes that the midchord is not
part of the inspection area specified in the referenced service
bulletin.
We agree with the commenter and have removed all references to the
word ``midchord'' from the supplemental NRPM.
Request To Clarify Service Information
One commenter states that Revision 1 of the referenced service
bulletin was added to paragraph (a), ``Restatement of Requirements of
AD 99-24-07,'' of the original NPRM as an additional source of service
information for doing the modification required by that paragraph. The
commenter notes that Revision 1 was not specified in the original
requirements of AD 99-24-07. However, the commenter does not ask for
any change to the NPRM.
We agree that Revision 1 of the service bulletin was not in the
original requirements of AD 99-24-07. The paragraph titled ``Actions
Since Issuance of Previous Rule,'' in the preamble of the NPRM,
provides an explanation of the reason Revision 1 was added: It
describes new procedures for an examination of the middle gusset of the
inboard side load fitting to determine if the angle between the middle
gusset and the outboard face of the lug is out of alignment. If the
angle is out of alignment, the corrective action involves machining the
middle gusset to the specified angle. For operators that already did
the modification, the original issue of the service bulletin is carried
over from AD 99-24-07 into paragraph (a) of the supplemental NPRM.
Request To Change Paragraph (b)(2)(ii)
One commenter states that the actions proposed by paragraph
(b)(2)(ii) of the NPRM are to be accomplished even if a repair has been
installed, due to cracking found per the inspection proposed by
paragraph (b)(2) of the NPRM. The commenter notes that this may lead
operators to alter repairs previously approved by the Manager of the
Seattle Aircraft Certification Office (ACO), per paragraph (b)(2)(i) of
the NPRM. The commenter adds that this would require operators to
obtain approvals for alternative methods of compliance per paragraph
(c)(1) of the NPRM. The commenter states that this may cause redundant
work and would consume valuable resources at both the airline and the
FAA. The commenter asks that paragraph (b)(2)(ii) of the NPRM be
separated into two paragraphs, one for repaired holes and one for holes
with no cracking.
We do not agree with the commenter. If a repair was done per a
previous approval by the Manager of the Seattle ACO, paragraph
(b)(2)(ii) of this AD (now added to paragraph (e) of the supplemental
NPRM) must still be done. The actions specified in Revision 2 of the
service bulletin increase the diameter of the fastener holes specified
in Revision 1 of the service bulletin, therefore, we do not agree to
further change paragraph (e) of this supplemental NPRM.
Explanation of Changes Made to NPRM
We have changed the service bulletin citation throughout this
supplemental NPRM to exclude the Evaluation Form. The form is intended
to be completed by operators and submitted to the manufacturer to
provide input on the quality of the service bulletin; however, this AD
does not include such a requirement.
We have changed all references to ``detailed visual inspection'' in
the NPRM to ``detailed inspection'' in this supplemental NPRM.
In addition, although Revision 2 of the service bulletin specifies
an inspection of only 14 aft bulkhead fasteners, paragraph (b) of this
supplemental NPRM requires inspection of all 20 aft bulkhead fasteners.
Further, the service bulletin specifies an inspection of only 2
fasteners of the lower spar fitting located in Panel 7 at Location 37,
but this supplemental NPRM requires inspection of all 8 fasteners, as
clarified in Notes 2 and 4.
Revision 2 also specifies that operators can use tools of their own
design as alternatives to Boeing-supplied tools when doing the actions
specified in the service bulletin. Paragraph (a) of this supplemental
NPRM prohibits the use of such tools, except those specified in Figures
3 and 5 of the Accomplishment Instructions of Revision 2 of the service
bulletin.
Conclusion
Since these changes expand the scope of the originally proposed
rule, we have determined that it is necessary to reopen the comment
period to provide additional opportunity for public comment.
Cost Impact
There are approximately 394 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 176 airplanes of U.S. registry
would be affected by this proposed AD.
The modification that is currently required by AD 99-24-07 takes
approximately 1,049 work hours per airplane to accomplish, at an
average labor rate of $60 per work hour. This work hour figure includes
the time it
[[Page 18172]]
will take to remove and reinstall the struts from the airplane as well
as the time required to gain and close access to the adjacent wing
structure. Based on these figures, the cost impact of the currently
required modification on U.S. operators is estimated to be $11,077,440,
or $62,940 per airplane.
This cost impact figure does not reflect the cost of the
terminating actions described in the service bulletins listed in
paragraph I.C., Table I, ``Strut Improvement Bulletins,'' on page 6 of
Boeing Service Bulletin 757-54-0035, that are required to be
accomplished prior to, or concurrently with, the modification of the
nacelle strut and wing structure. Since some operators may have
accomplished certain modifications on some or all of the airplanes in
the fleet, while other operators may not have accomplished any of the
modifications on any of the airplanes in the fleet, the FAA is unable
to provide a reasonable estimate of the cost of accomplishing the
terminating actions described in the service bulletins listed in Table
I of the service bulletin.
It would take approximately 1 work hour per airplane to accomplish
the new detailed inspection of the middle gusset, at an average labor
rate of $60 per work hour. Based on these figures, the cost impact of
the inspection proposed by this AD is estimated to be $10,560, or $60
per airplane.
It would take approximately 8 work hours per airplane to accomplish
the new fastener removal and eddy current inspection, at an average
labor rate of $60 per work hour. Based on these figures, the cost
impact of the removal and inspection proposed by this AD is estimated
to be $84,480, or $480 per airplane.
The cost impact figures discussed above are based on assumptions
that no operator has yet accomplished any of the 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 39-11431 (64 FR
66370, November 26, 1999), and by adding a new airworthiness directive
(AD), to read as follows:
Boeing: Docket 2000-NM-376-AD. Supersedes AD 99-24-07, Amendment 39-
11431.
Applicability: Model 757 series airplanes equipped with Rolls
Royce 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 (h)(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 cracking in primary strut structure and
consequent reduced structural integrity of the strut, accomplish the
following:
Restatement of Requirements of AD 99-24-07
Modification
(a) Modify the nacelle strut and wing structure according to
Boeing Service Bulletin 757-54-0035, dated July 17, 1997; or
Revision 1, dated April 15, 1999; at the later of the times
specified in paragraph (a)(1) or (a)(2) of this AD. All of the
terminating actions described in the service bulletins and listed in
paragraph I.C., Table I, ``Strut Improvement Bulletins,'' on page 6
of Boeing Service Bulletin 757-54-0035, and on page 7 of Revision 1
of the service bulletin, as applicable, must be accomplished
according to those service bulletins prior to, or concurrently with,
the accomplishment of the modification of the nacelle strut and wing
structure required by this paragraph. After the effective date of
this AD, use only Revision 1 of the service bulletin.
(1) Prior to the accumulation of 37,500 total flight cycles, or
prior to 20 years since the date of manufacture of the airplane,
whichever occurs first.
(2) Within 3,000 flight cycles after January 3, 2000 (the
effective date of AD 99-24-07, amendment 39-11431).
New Requirements of This AD
Inspections/Corrective Actions
(b) For airplanes on which the modification required by
paragraph (a) of this AD has not been done according to Boeing
Service Bulletin 757-54-0035, dated July 17, 1997: Before the
accumulation of 15,000 total flight cycles, or within 6 months after
the effective date of this AD, whichever is later, do a detailed
inspection of the 20 aft bulkhead fasteners of the lower spar
fitting for loose or missing fasteners, according to a method
approved by the Manager, Seattle Aircraft Certification Office
(ACO), FAA. Before further flight, replace any loose or missing
fasteners with new fasteners according to Boeing Service Bulletin
757-54-0035, Revision 1, dated April 15, 1999; or Revision 2, dated
June 13, 2002, excluding Evaluation Form. Repeat the inspection
after that at least every 6 months.
Note 2: The 20 aft bulkhead fasteners are located in Panel 7 at
Locations 36, 37, and 41. The number of fasteners at Location 37 has
increased from 2 to 8 fasteners. Figure 30 of Boeing Service
Bulletin 757-54-0035, Revision 2, dated June 13, 2002, illustrates
the location of the fasteners.
Note 3: For the purposes of this AD, a detailed inspection is
defined as: ``An intensive visual examination of a specific
structural area, system, installation, or assembly to detect damage,
failure, or irregularity. Available lighting is normally
supplemented with a direct source of good lighting at intensity
deemed appropriate by
[[Page 18173]]
the inspector. Inspection aids such as mirror, magnifying lenses,
etc., may be used. Surface cleaning and elaborate access procedures
may be required.''
(c) For airplanes on which the modification required by
paragraph (a) of this AD has been done according to Boeing Service
Bulletin 757-54-0035, dated July 17, 1997: Within 15,000 flight
cycles after doing the modification required by paragraph (a) of
this AD, or within 3 years after the effective date of this AD,
whichever is later; do a one-time detailed inspection of the middle
gusset of the inboard side load fitting for proper alignment,
according to Part II of the Accomplishment Instructions of Boeing
Service Bulletin 757-54-0035, Revision 1, dated April 15, 1999; or
Revision 2, dated June 13, 2002, excluding Evaluation Form. If the
gusset is not aligned properly, before further flight, machine the
gusset to the specified angle according to the service bulletin.
(d) Before further flight after doing paragraph (c) of this AD,
do the actions required by paragraphs (d)(1) and (d)(2) of this AD.
(1) Remove the aft bulkhead fasteners of the lower spar fitting
and do a one-time eddy current inspection of those fastener holes
for cracking, according to Part V of the Accomplishment Instructions
of Boeing Service Bulletin 757-54-0035, Revision 1, dated April 15,
1999; or Revision 2, dated June 13, 2002, excluding Evaluation Form.
(2) Do a detailed inspection of the 8 fasteners of the lower
spar fitting for loose or missing fasteners, according to a method
approved by the Manager, Seattle ACO. Before further flight, replace
any loose or missing fasteners with new fasteners according to
Boeing Service Bulletin 757-54-0035, Revision 1, dated April 15,
1999; or Revision 2, dated June 13, 2002, excluding Evaluation Form.
Note 4: The 8 fasteners are located in Panel 7 at Location 37.
The number of fasteners at Location 37 has increased from 2 to 8
fasteners. Figure 30 of Boeing Service Bulletin 757-54-0035,
Revision 2, dated June 13, 2002, excluding Evaluation Form,
illustrates the location of the fasteners.
(e) If any cracking is found during any inspection required by
this AD: Before further flight, repair according to a method
approved by the Manager, Seattle ACO; or according to data meeting
the type certification basis of the airplane approved by a Boeing
Company Designated Engineering Representative 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 Manager's approval letter must
specifically reference this AD.
(f) If no cracking is found during any inspection required by
this AD, or after repair of cracking as required by paragraph (e) of
this AD, before further flight, increase the diameter of the
fastener holes and install new fasteners according to Boeing Service
Bulletin 757-54-0035, Revision 2, dated June 13, 2002, excluding
Evaluation Form.
(g) Except as identified in Figures 3 and 5 of the
Accomplishment Instructions of Boeing Service Bulletin 757-54-0035,
Revision 2, dated June 13, 2002, excluding Evaluation Form, the
actions must be done using Boeing-supplied tools.
Alternative Methods of Compliance
(h)(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, 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.
(2) Alternative methods of compliance, approved previously in
accordance with AD 99-24-07, amendment 39-11431, are approved as
alternative methods of compliance with paragraph (a) of this AD.
Note 5: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
Special Flight Permit
(i) 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.
Issued in Renton, Washington, on April 9, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 03-9138 Filed 4-14-03; 8:45 am]
BILLING CODE 4910-13-P