[Federal Register: March 4, 2003 (Volume 68, Number 42)]
[Proposed Rules]
[Page 10185-10188]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr04mr03-16]
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Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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[[Page 10185]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2001-NM-228-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 Series Airplanes
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 747
series airplanes, that currently requires inspections to detect
cracking of the front spar web of the wing, and corrective action, if
necessary. This action would add one airplane to the applicability,
change certain compliance times, add certain new requirements, and
provide an optional modification. The actions specified by the proposed
AD are intended to detect and correct fatigue cracking of the front
spar web, which could result in fuel leaking onto an engine and a
consequent fire. This action is intended to address the identified
unsafe condition.
DATES: Comments must be received by April 18, 2003.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 2001-NM-228-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. 2001-NM-228-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: Tamara Anderson, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
917-6421; 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-228-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-228-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
On December 14, 2000, the FAA issued AD 2000-25-12, amendment 39-
12047 (65 FR 81331, December 26, 2000), applicable to certain Boeing
Model 747 series airplanes, to require inspections to detect cracking
of the front spar web of the wing, and corrective action, if necessary.
That action was prompted by a report indicating that an operator found
a 24-inch-long crack in the front spar web of the right wing. The
requirements of that AD are intended to detect and correct fatigue
cracking of the front spar web, which could result in fuel leaking onto
an engine and a consequent fire.
Actions Since Issuance of Previous Rule
Since the issuance of AD 2000-25-12, an operator reported finding a
crack in the front spar web during accomplishment of the modification
specified in paragraph (b) of that AD on a Model 747 series airplane.
The airplane had accumulated approximately 19,500 total flight cycles
and 82,000 total flight hours. The crack was found outboard of the new
web section at approximately front spar station inboard (FSSI) 694,
common to the splice plate and upper chord. Cracking of the web in this
area can result in fuel leakage into the struts, which could result in
excess fuel drainage onto an engine and a consequent fire.
Additionally, it has been determined that the optional web
inspections specified in paragraph (a) of the existing AD do not
provide the crack detection necessary to support the compliance time
for the repeat inspection intervals. Therefore, the optional web
inspections have been removed from the requirements of this AD.
[[Page 10186]]
Related AD
On May 3, 1999, the FAA issued AD 99-10-09, amendment 39-11162 (64
FR 25194, May 11, 1999), applicable to certain Boeing Model 747-100, -
200, and 747-SP series airplanes and military type E-4B airplanes. That
AD requires repetitive inspections to detect cracking of the wing front
spar web, and repair of cracked structure. That AD provides for
optional terminating action (modification) for the repetitive
inspection requirements. This proposed AD would require post-
modification inspections of that modification, if accomplished.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Alert Service Bulletin
747-57A2311, Revision 1, including Appendices A and B, dated June 14,
2001; and Boeing Service Bulletin 747-57A2311, Revision 2, dated
February 21, 2002; both including Evaluation Form. The service
bulletins describe procedures for various repetitive inspections
(detailed, ultrasonic, high frequency eddy current (HFEC)) of the front
spar web between the fixed leading edge seal ribs at FSSI 628 through
711 inclusive, to find cracking of the front spar web of the wing, and
corrective action, if necessary. The inspections include:
[sbull] For Group 1 through Group 8 airplanes on which the optional
modification specified in AD 99-10-09, amendment 39-11162, has not been
done, the affected area is divided into 2 zones. Part 1 of the service
bulletin describes procedures for inspecting to find cracking of the
front spar web between the seal rib at FSSI 628 and the rib post at
FSSI 684 (Zone A); and between FSSI 684 and FSSI 711 inclusive (Zone
B).
[sbull] For Group 1 through Group 8 airplanes on which the optional
modification specified in AD 99-10-09, amendment 39-11162, has been
done, the affected area is divided into 3 zones. Part 1 of the service
bulletin describes procedures for inspecting to find cracking of the
front spar web between the seal rib at FSSI 628 and the rib post at
FSSI 668 (Zone A); between FSSI 693 and FSSI 711 inclusive (Zone B);
and between FSSI 668 and FSSI 693 inclusive (Zone C).
[sbull] For Group 9 through Group 31 airplanes, the affected area
is divided into two zones. Part 1 of the service bulletin describes
procedures for inspecting to find cracking of the front spar web
between the seal rib at FSSI 628 and the rib post at FSSI 684 (Zone A);
and between FSSI 684 and FSSI 711 inclusive (Zone B).
[sbull] For Group 1 through Group 8 airplanes, the inspections in
this service bulletin do not replace the inspections required by AD 99-
10-09.
The service bulletins also describe procedures for optional
modification of the front spar web. The procedures include removing the
existing fasteners and doing an open hole, rotating probe HFEC
inspection of the holes for web cracks. If no cracks are found, the
service bulletin describes procedures for oversizing the holes, and
installing tension type fasteners. The service bulletin also describes
procedures for an operational test after doing the modification.
Accomplishment of the actions specified in the service bulletin is
intended to adequately address the identified unsafe condition.
In addition, the service bulletin specifies that repair
instructions for cracking should be obtained from the manufacturer.
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 2000-25-12, to continue to require
inspections to detect cracking of the front spar web of the wing, and
corrective action, if necessary. This new action would add one airplane
to the applicability, change certain compliance times, add certain new
requirements, and provide an optional modification. The actions would
be required to be accomplished in accordance with the service bulletin
described previously, except as discussed below.
Differences Between Service Information and This Proposed AD
The service bulletin specifies that the manufacturer may be
contacted for disposition of certain repair conditions, but this
proposed AD would require the repair of those conditions to be
accomplished in accordance with a method approved by the FAA, or in
accordance with data meeting the type certification basis of the
airplane approved by a Boeing Company Designated Engineering
Representative who has been authorized by the FAA to make such
findings.
Cost Impact
There are approximately 479 Model 747 series airplanes of the
affected design in the worldwide fleet. The FAA estimates that 97
airplanes of U.S. registry would be affected by this proposed AD.
The external inspections that are required by AD 2000-25-12 take
approximately 48 work hours per airplane (not including access and
close-up), at an average labor rate of $60 per work hour. Based on
these figures, the cost impact of the external inspections is estimated
to be $2,880 per airplane, per inspection cycle.
The new inspections that are proposed in this AD action would take
approximately 74 work hours per airplane to accomplish, at an average
labor rate of $60 per work hour. Based on these figures, the cost
impact of the new inspections is estimated to be $4,440 per airplane,
per inspection cycle.
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.
Should an operator elect to accomplish the optional modification
that would be provided by this AD action, it would take approximately
40 work hours to accomplish, at an average labor rate of $60 per work
hour. The cost of required parts would be between $8,606 and $28,036
per airplane. Based on these figures, the cost impact of the optional
modification would be between $11,006 and $30,436 per airplane.
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
[[Page 10187]]
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 39-12047 (65 FR
81331, December 26, 2000), and by adding a new airworthiness directive
(AD), to read as follows:
Boeing: Docket 2001-NM-228-AD. Supersedes AD 2000-25-12, Amendment
39-12047.
Applicability: Model 747 series airplanes, as listed in Boeing
Service Bulletin 747-57A2311, Revision 2, dated February 21, 2002;
certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
otherwise 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 detect and correct fatigue cracking of the front spar web of
the wing, which could result in fuel leaking onto an engine and a
consequent fire, accomplish the following:
Restatement of Certain Requirements of AD 2000-25-12
Repetitive Inspections
(a) Excluding Group 31 airplanes, as specified in Boeing Service
Bulletin 747-57A2311, Revision 2, dated February 21, 2002: At the
later of the times specified in paragraphs (a)(1) and (a)(2) of this
AD, except as provided by paragraph (b) of this AD, perform the Part
1 external web inspection--including detailed, ultrasonic, and high
frequency eddy current (HFEC) inspections--to detect cracking of the
front spar web of the wing, in accordance with Boeing Alert Service
Bulletin 747-57A2311, dated January 27, 2000. Repeat the inspections
thereafter at intervals not to exceed 2,000 flight cycles until
accomplishment of the inspections required by paragraph (e) of this
AD. Accomplishment of an optional inspection of the front spar web
per AD 2000-25-12, amendment 39-12047, is considered acceptable for
compliance with the applicable inspection requirement in this
paragraph.
Note 2: 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
mirrors, magnifying lenses, etc., may be used. Surface cleaning and
elaborate access procedures may be required.''
(1) Prior to the accumulation of 13,000 total flight cycles or
30,000 total flight hours, whichever occurs first.
(2) Within 18 months after January 30, 2001 (the effective date
of this AD 2000-25-12, amendment 39-12047).
Exception for Modified Airplanes
(b) Except as provided by paragraph (g) of this AD, for
airplanes on which the front spar web between front spar station
inboard (FSSI) 668 and FSSI 692 has been replaced before the
effective date of this AD with a shot-peened front spar web, in
accordance with AD 99-10-09, amendment 39-11162: Within 13,000
flight cycles or 30,000 flight hours after the replacement,
whichever occurs first, inspect the new section of the front spar
web that overlaps with the inspection area specified in Boeing Alert
Service Bulletin 747-57A2311 (the area between FSSI 668 and FSSI
684), dated January 27, 2000. Repeat the inspections thereafter, in
accordance with paragraph (a) of this AD.
Repair
(c) If any cracking is detected during any inspection required
by this AD, 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 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
Compliance Times
(d) Where the compliance time inspection threshold is based on
``after the date of this service bulletin,'' in Boeing Alert Service
Bulletin 747-57A2311, Revision 1, including Appendices A and B,
dated June 14, 2001; or Boeing Service Bulletin 747-57A2311,
Revision 2, dated February 21, 2002; both excluding Evaluation Form:
This AD requires compliance within the inspection interval specified
in the service bulletin ``after the effective date of this AD.''
Repetitive Inspections
(e) Except as provided by paragraph (g) of this AD: Do detailed,
ultrasonic, and high frequency eddy current (HFEC) inspections, as
applicable, to find cracking of the front spar web of the wing, in
accordance with Part 1 of the Accomplishment Instructions of Boeing
Alert Service Bulletin 747-57A2311, Revision 1, including Appendices
A and B, dated June 14, 2001; or Boeing Service Bulletin 747-
57A2311, Revision 2, dated February 21, 2002; both excluding
Evaluation Form. Do the inspections at the applicable initial
inspection threshold times specified in Figure 1, Tables 1 through 8
inclusive, of the service bulletin. Repeat the applicable inspection
thereafter at the applicable repeat inspection interval specified in
Figure 1, Tables 1 through 8 inclusive, of the service bulletin.
Accomplishment of the inspections required by this paragraph
terminates the repetitive inspections required by paragraph (a) of
this AD.
Optional Modification
(f) Accomplishment of the optional modification of the front
spar web of the wing (includes removing the existing fasteners and
doing an open hole, rotating probe HFEC inspection of the holes for
web cracks, and if no cracks are found, oversizing the holes, and
installing tension type fasteners), in accordance with Part 2 of the
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
57A2311, Revision 1, including Appendices A and B, dated June 14,
2001; or Boeing Service Bulletin, Revision 2, dated February 21,
2002; both excluding Evaluation Form; terminates the repetitive
inspections required by paragraph (e) of this AD.
Post-Modification Inspections
(g) For airplanes on which the actions specified in paragraph
(b) or (f) of this AD have been done before the effective date of
this AD: In lieu of the inspections required by paragraph (b) or (e)
of this AD, as applicable, do the applicable post-modification
inspection specified in Part 1 of the Accomplishment Instructions of
Boeing Alert Service Bulletin 747-57A2311, Revision 1, including
Appendices A and B, dated June 14, 2001; or Boeing Service Bulletin
747-57A2311, Revision 2, dated February 21, 2002; both excluding
Evaluation Form; at the post-modification inspection threshold times
specified in Figure 1, Tables 1 through 8 inclusive, of the service
bulletin. Repeat the applicable inspection thereafter at the
applicable post-modification repeat inspection interval specified in
Figure 1, Tables 1 through 8 inclusive, of the service bulletin.
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
[[Page 10188]]
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 2000-25-12, amendment 39-12047, are approved as
alternative methods of compliance with paragraph (c) of this AD.
Note 3: 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
(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 February 24, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 03-4851 Filed 3-3-03; 8:45 am]
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