[Federal Register: June 16, 2004 (Volume 69, Number 115)]
[Rules and Regulations]
[Page 33561-33565]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr16jn04-9]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2000-NM-376-AD; Amendment 39-13666; AD 2004-12-07]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 757 Series Airplanes
Equipped With Rolls Royce RB211 Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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[[Page 33562]]
SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to certain Boeing Model 757 series airplanes equipped
with Rolls Royce RB211 engines, that currently requires modification of
the nacelle strut and wing structure. This amendment requires, for
certain airplanes, repetitive detailed inspections of certain aft
bulkhead fasteners for loose or missing fasteners, and corrective
action if necessary. For certain other airplanes, this amendment
requires a one-time detailed inspection of the middle gusset of the
inboard side load fitting for proper alignment and realignment if
necessary; a one-time eddy current inspection of certain fastener holes
for cracking, and repair if necessary; and a detailed inspection of
certain fasteners for loose or missing fasteners; and replacement with
new fasteners if necessary. The actions specified by this 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: Effective July 21, 2004.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of July 21, 2004.
ADDRESSES: The service information referenced in this AD may be
obtained from Boeing Commercial Airplanes, P.O. Box 3707, Seattle,
Washington 98124-2207. This information may be examined at the Federal
Aviation Administration (FAA), Transport Airplane Directorate, 1601
Lind Avenue, SW., Renton, Washington; or at the National Archives and
Records Administration (NARA). For information on the availability of
this material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html
.
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: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) by superseding 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, was published as a supplemental Notice of
Proposed Rulemaking in the Federal Register on April 15, 2003 (68 FR
18170). The action proposed to continue to require modification of the
nacelle strut and wing structure. The action proposed to require, for
certain airplanes, repetitive detailed inspections of certain aft
bulkhead fasteners for loose or missing fasteners, and corrective
action if necessary. For certain other airplanes, the action proposed
to require a one-time detailed inspection of the middle gusset of the
inboard side load fitting for proper alignment and realignment if
necessary; a one-time eddy current inspection of certain fasteners
holes for cracking; and repair if necessary; and a detailed inspection
of certain fasteners for loose or missing fasteners; and replacement
with new fasteners if necessary. Additionally, the action proposed to
require that certain actions specified in Boeing Service Bulletin 757-
54-0035, Revision 2, dated June 13, 2002 (specified in the supplemental
NPRM as one of the appropriate sources of service information), be done
using Boeing-supplied tools.
Request for 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.
Comments Received That Resulted in Changes to the AD
Requests To Extend Repetitive Inspection Interval
Several commenters request that the repetitive inspection interval
of every six months proposed by paragraph (b) of the supplemental NPRM
be extended. Two commenters state that repetitive inspection intervals
of every 3,000 flight cycles would be less of a burden for the
operators. Another commenter advises that the airplane manufacturer's
intent was to require repetitive inspections every 12,000 flight cycles
or 72 months, whichever occurs first.
The FAA concurs that the repetitive inspection interval may be
extended somewhat. We understand that the manufacturer has recommended
an interval of every 12,000 flight cycles or 72 months. However, we
have recently received reports of field experience that show the
fasteners can loosen in less than 72 months. Therefore, we have revised
paragraph (b) of the AD to specify a repetitive inspection interval not
to exceed 6,000 flight cycles or 36 months, whichever occurs first.
Requests To Clarify Paragraph (f) of the Supplemental NPRM
One commenter states that the way the supplemental NPRM is written,
it would require the actions specified in paragraph (f) of the
supplemental NPRM to be accomplished after each repetitive inspection
required by paragraph (b) of the supplemental NPRM. Two commenters
request that the supplemental NPRM be revised to clearly specify that
accomplishment of the requirements of paragraph (f) of the supplemental
NPRM is terminating action.
We agree with the need to clarify paragraph (f) of the supplemental
NPRM. The requirements of paragraph (f) of the AD (to increase the
diameter of the fastener holes and to install new fasteners) apply to
those airplanes on which the actions specified in paragraph (d) of the
AD have been accomplished. We have revised paragraph (f) of the AD to
reflect that clarification. Additionally, we agree that the actions
specified in paragraph (f) of this AD terminates the repetitive
inspection requirements of this AD. We have revised the AD accordingly.
Comments Received That Resulted in No Change to the Supplemental NPRM
Requests To Withdraw Rulemaking Until New Service Information Is Issued
Several commenters request that the supplemental NPRM be withdrawn
and that, instead, new rulemaking be proposed to specify that the
initial inspection specified in paragraph (b) of the supplemental NPRM
be accomplished within 90 days after the release of a new Boeing
service bulletin (Boeing Alert Service Bulletin 757-54A0047). The
commenters state that using the new service information would simplify
and clarify the actions proposed in the supplemental NPRM.
We do not agree that this AD should be withdrawn. We have not
reviewed or approved new service information specified by the
commenters. In this case, we find that to withdraw this AD and initiate
new proposed rulemaking (providing for public opportunity to comment)
would significantly delay the rulemaking process and would be
inappropriate in light of the identified unsafe condition. Therefore,
no change is necessary to the AD in this regard. In the future, if the
manufacturer elects to provide new service information, the service
information can be evaluated and approved in accordance with paragraph
(h) of this AD.
[[Page 33563]]
Request To Extend Compliance Time of Paragraph (b) of the Supplemental
NPRM
One commenter requests that, for airplanes that have completed the
modification specified in Boeing Service Bulletin 757-54-0035, the
compliance time specified in paragraph (b) of the supplemental NPRM be
extended. The commenter states that the compliance time should be
extended because the previous modification was done on those airplanes
in a shop environment.
We do not agree that extending the compliance time specified in
paragraph (b) of this AD is necessary. The requirements of paragraph
(b) of this AD apply only to airplanes that have not been modified per
Boeing Service Bulletin 757-54-0035. Therefore, no change is necessary
in this regard to the AD.
Requests To Revise Inspection Method for Loose or Missing Fasteners
Two commenters request that a method of inspecting for loose or
missing fasteners without the engine in place be specified. The
commenters state that the inspection method specified in the
supplemental NPRM is burdensome to accomplish with the engine in place.
We do not agree with the commenters' request. Since the
manufacturer has not provided us with service information describing
such a method of inspection, we have not reviewed and approved such an
inspection method. However, under the provisions of paragraph (h) of
the AD, we may approve requests for an alternative inspection method if
data are submitted to substantiate that such an alternative inspection
method would provide an acceptable level of safety.
Request for an Alternative Inspection Method
One commenter, the manufacturer, requests that a simple gap check
be performed with a feeler or wire gage in lieu of the inspection in
paragraph (c) of the supplemental NPRM. The commenter explains that
this can be done with the strut still installed, which is described in
Boeing Service Bulletin 757-54-0035, Revision 2. The commenter further
recommends that a minimum gap of 0.030 inch be maintained between the
middle gusset on the inboard side load fitting and the strut clevis
lug.
We do not agree with permitting such an alternative method of
inspection at this time, since the gap check has not been sufficiently
defined for us to review and approve. However, under the provisions of
paragraph (h) of the AD, we may approve requests for an alternative
inspection method if data are submitted to substantiate that such an
alternative method would provide an acceptable level of safety.
Request To Use Alternative Method of Oversizing Holes
One commenter requests approval for using procedures to oversize
holes specified in the Structural Repair Manual (SRM) in lieu of using
Boeing-supplied tools specified in paragraph (g) of the supplemental
NPRM. The commenter notes that there is a limited supply of those
tools.
We do not agree with the commenter's request. In certain cases,
operator supplied tools have contributed to unsafe conditions. However,
under the provisions of paragraph (h) of the AD, we may approve
requests for an alternative method of oversizing holes if data are
submitted to substantiate that such a method to oversize holes would
provide an acceptable level of safety.
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 changes previously
described. The FAA has determined that these changes will neither
increase the economic burden on any operator nor increase the scope of
the AD.
Change to the Code of Federal Regulations
On July 10, 2002, the FAA issued a new version of 14 CFR part 39
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness
directives system. The regulation now includes material that relates to
altered products, special flight permits, and alternative methods of
compliance. Because we have now included this material in part 39, only
the office authorized to approve AMOCs is identified in each individual
AD. However, for clarity and consistency in this AD, we have retained
the language of the supplemental NPRM regarding that material.
Change to Labor Rate Estimate
We have reviewed the figures we have used over the past several
years to calculate AD costs to operators. To account for various
inflationary costs in the airline industry, we find it necessary to
increase the labor rate used in these calculations from $60 per work
hour to $65 per work hour. The cost impact information, below, reflects
this increase in the specified hourly labor rate.
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
will be affected by this 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 $65 per work hour. This work hour figure includes
the time it 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
$12,000,560, or $68,185, 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 7 of
Revision 2 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 will take approximately 1 work hour per airplane to accomplish
the new detailed inspection of the middle gusset, at an average labor
rate of $65 per work hour. Based on these figures, the cost impact of
the inspection required by this AD is estimated to be $11,440, or $65
per airplane.
It will take approximately 8 work hours per airplane to accomplish
the new fastener removal and eddy current inspection, at an average
labor rate of $65 per work hour. Based on these figures, the cost
impact of the removal and inspection required by this AD is estimated
to be $91,520, or $520 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
[[Page 33564]]
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
0
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
0
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]
0
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), amendment 39-13666, to read as follows:
2004-12-07 Boeing: Amendment 39-13666. Docket 2000-NM-376-AD.
Supersedes AD 99-24-07, Amendment 39-11431.
Applicability: Model 757 series airplanes equipped with Rolls
Royce RB211 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 (AMOC) 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; Revision
1, dated April 15, 1999; or Revision 2, dated June 13, 2002, 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, on
page 7 of Revision 1 of the service bulletin, and on Page 7 of
Revision 2 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 2 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
thereafter at intervals not to exceed 6,000 flight cycles or 36
months, whichever occurs first. Accomplishment of the actions
required by paragraph (a) of this AD constitutes terminating action
for the requirements of this paragraph.
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 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
[[Page 33565]]
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 the inspection required by
paragraph (d) 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 AMOC 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) AMOCs, approved previously in accordance with AD 99-24-07,
amendment 39-11431, are approved as AMOCs with paragraph (a) of this
AD.
Note 5: Information concerning the existence of approved AMOCs
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.
Incorporation by Reference
(j) Unless otherwise specified, the actions shall be done in
accordance with Boeing Service Bulletin 757-54-0035, Revision 1,
dated April 15, 1999; or Boeing Service Bulletin 757-54-0035,
Revision 2, dated June 13, 2002. 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 Airplanes, 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
National Archives and Records Administration (NARA). For information
on the availability of this material at NARA, call (202) 741-6030,
or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html
.
Effective Date
(k) This amendment becomes effective on July 21, 2004.
Issued in Renton, Washington, on May 25, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 04-13144 Filed 6-15-04; 8:45 am]
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