[Federal Register Volume 68, Number 72 (Tuesday, April 15, 2003)]
[Proposed Rules]
[Pages 18170-18173]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-9138]


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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.

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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equipped with Rolls Royce RB211 engines, that would have superseded an 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: 
[email protected]. 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

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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