[Federal Register Volume 68, Number 42 (Tuesday, March 4, 2003)]
[Proposed Rules]
[Pages 10185-10188]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-4851]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
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 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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 

  Federal Register / Vol. 68, No. 42 / Tuesday, March 4, 2003 / 
Proposed Rules  

[[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: 
[email protected]. 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]
BILLING CODE 4910-13-P