Document ID: FAA-2007-0004-0056
Agency: faa
Document Type: Notice
Title: Airworthiness Directives; Boeing Model 747 Airplanes
Posted Date: 2007-08-16T04:00Z

[Federal Register: August 16, 2007 (Volume 72, Number 158)]
[Proposed Rules]               
[Page 45973-45976]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr16au07-27]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28989; Directorate Identifier 2007-NM-070-AD]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 747 Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede an existing airworthiness 
directive (AD) that applies to certain Boeing Model 747-200B, 747-200C, 
747-200F, 747-300, 747-400, and 747SP series airplanes. The existing AD 
currently requires doing a detailed inspection of the left and right 
longeron extension fittings, and corrective action if necessary. This 
proposed AD would add airplanes to the applicability of the existing 
AD. This proposed AD results from reports that accidental drilling 
damage to the longeron extension fittings was found on airplanes not 
subject to the existing AD. We are proposing this AD to detect and 
correct accidental drilling damage of the

[[Page 45974]]

longeron extension fittings, which could lead to cracking of the 
longeron extension fittings and result in rapid decompression of the 
airplane.

DATES: We must receive comments on this proposed AD by October 1, 2007.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 

the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov
 and follow the instructions for sending your 

comments electronically.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Fax: (202) 493-2251.
     Hand Delivery: Room W12-140 on the ground floor of the 
West Building, 1200 New Jersey Avenue, SE., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for service information identified in this 
proposed AD.

FOR FURTHER INFORMATION CONTACT: Ivan Li, Aerospace Engineer, Airframe 
Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind 
Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6437; 
fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed in the ADDRESSES section. Include the docket number ``Docket No. 
FAA-2007-28989; Directorate Identifier 2007-NM-070-AD'' at the 
beginning of your comments. We specifically invite comments on the 
overall regulatory, economic, environmental, and energy aspects of the 
proposed AD. We will consider all comments received by the closing date 
and may amend the proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov
, including any personal information you provide. We will 

also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or may 
can visit http://dms.dot.gov.

Examining the Docket

    You may examine the AD docket on the Internet at http://dms.dot.gov
, or in person at the Docket Operations office between 9 

a.m. and 5 p.m., Monday through Friday, except Federal holidays. The 
Docket Operations office (telephone (800) 647-5527) is located on the 
ground floor of the West Building at the DOT street address stated in 
the ADDRESSES section. Comments will be available in the AD docket 
shortly after the Docket Management System receives them.

Discussion

    On April 28, 2006, we issued AD 2006-10-04, amendment 39-14588 (71 
FR 27592, May 12, 2006), for certain Boeing Model 747-200B, 747-200C, 
747-200F, 747-300, 747-400, and 747SP series airplanes. That AD 
requires doing a detailed inspection of the left and right longeron 
extension fittings, and corrective action if necessary. That AD 
resulted from cracking found in the longeron extension fitting at body 
station 1480 due to accidental damage during production. We issued that 
AD to detect and correct cracking in the longeron extension fitting, 
which could result in rapid decompression of the airplane.

Actions Since Existing AD Was Issued

    Since we issued AD 2006-10-04, we received reports that accidental 
drill damage was discovered during inspections of the longeron 
extension fittings of five airplanes not subject to that AD, including 
one airplane manufactured before the airplanes specified in the 
effectivity of Boeing Alert Service Bulletin 747-53A2515, dated October 
20, 2005 (cited in AD 2006-10-04 as the appropriate source of service 
information). Boeing therefore concluded that additional airplanes 
which might be subject to the unsafe condition should be added to the 
effectivity of a revision of that service bulletin.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 747-53A2515, 
Revision 1, dated March 1, 2007. Revision 1 of the alert service 
bulletin is essentially the same as the original issue, except that 
airplanes have been added to its effectivity.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to develop on other airplanes of the 
same type design. For this reason, we are proposing this AD, which 
would supersede AD 2006-10-04 and would retain certain requirements of 
the existing AD. The proposed AD would also add airplanes to the 
applicability of the existing AD. The proposed AD would remove the 
reporting requirement of the existing AD. The proposed AD would also 
require accomplishing the actions specified in the service information 
described previously, except as discussed under ``Difference Between 
the Proposed AD and the Service Bulletin.''

Difference Between the Proposed AD and the Service Bulletin

    The service bulletin specifies to contact the manufacturer for 
instructions on how to repair certain conditions, but this proposed AD 
would require repairing those conditions in one of the following ways:
     Using a method that we approve; or
     Using data that meet the certification basis of the 
airplane, and that have been approved by an Authorized Representative 
for the Boeing Commercial Airplanes Delegation Option Authorization 
Organization whom we have authorized to make those findings.

Interim Action

    We consider this proposed AD interim action. If final action is 
later identified, we may consider further rulemaking then.

Costs of Compliance

    There are about 876 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 156 airplanes of 
U.S. registry.
    The actions specified by this proposed AD were previously required 
by AD 2006-10-04, which was applicable to approximately 25 airplanes of 
U.S. registry. The actions required by that AD take about 1 work hour 
per airplane. We estimated the cost of the current requirements of that 
AD on U.S. operators to be $2,000, or $80 per airplane. Some operators 
of the 25 airplanes subject to AD 2006-10-04 may have already initiated 
the required actions. This proposed AD would add

[[Page 45975]]

no new costs associated with those airplanes.
    This proposed AD would be applicable to approximately 131 
additional airplanes of U.S. registry. New actions required by this 
proposed AD would take about 1 work hour per airplane. Based on the 
current labor rate of $80 per work hour, we estimate the new costs 
imposed by this proposed AD on U.S. operators to be $10,480, or $80 per 
airplane. This figure is based on assumptions that no operator of these 
additional airplanes has yet done any of the proposed requirements of 
this AD, and that no operator would do those actions in the future if 
this AD were not adopted.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    For the reasons discussed above, I certify that the 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. 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD and placed it in the AD docket. See the 
ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
removing amendment 39-14588 (71 FR 27592, May 12, 2006) and adding the 
following new airworthiness directive (AD):

BOEING: Docket No. FAA-2007-28989; Directorate Identifier 2007-NM-
070-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by October 
1, 2007.

Affected ADs

    (b) This AD supersedes AD 2006-10-04.

Applicability

    (c) This AD applies to Boeing Model 747-100, 747-100B, 747-100B 
SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-
400F, 747SR, and 747SP series airplanes, certificated in any 
category; as identified in Boeing Alert Service Bulletin 747-
53A2515, Revision 1, dated March 1, 2007.

Unsafe Condition

    (d) This AD results from reports that accidental drilling damage 
to the longeron extension fittings was found on airplanes not 
subject to the existing AD. We are issuing this AD to detect and 
correct accidental drilling damage of the longeron extension 
fittings, which could lead to cracking of the longeron extension 
fittings and result in rapid decompression of the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Restatement of Certain Requirements of AD 2006-10-04

Detailed Inspection

    (f) For Group 1 airplanes identified in Boeing Alert Service 
Bulletin 747-53A2515, Revision 1, dated March 1, 2007: At the 
applicable compliance time specified in paragraph (f)(1) or (f)(2) 
of this AD, do a detailed inspection of the left and right longeron 
extension fittings for damage, and, before further flight, do the 
corrective action if applicable, by accomplishing all the applicable 
actions specified in the Accomplishment Instructions of Boeing Alert 
Service Bulletin 747-53A2515, dated October 20, 2005; or Revision 1, 
dated March 1, 2007.

    Note 1: Boeing Alert Service Bulletin 747-53A2515, dated October 
20, 2005; and Revision 1, dated March 1, 2007; refer to Boeing Alert 
Service Bulletin 747-53A2390, Revision 1, dated July 6, 2000, as an 
additional source of service information for replacing a damaged 
longeron fitting with a new longeron extension fitting.

    (1) For airplanes that have accomplished the inspection of the 
splice area for cracking as specified in Boeing Alert Service 
Bulletin 747-53A2390, dated July 31, 1997; or Revision 1, dated July 
6, 2000: Inspect in accordance with paragraph (f) of this AD before 
the airplane has accumulated 10,000 total flight cycles, or within 
1,000 flight cycles after June 16, 2006 (the effective date of AD 
2006-10-04), whichever is later.
    (2) For airplanes that have not accomplished the inspection of 
the splice area for cracking as specified in Boeing Alert Service 
Bulletin 747-53A2390, dated July 31, 1997; or Revision 1, dated July 
6, 2000: Inspect in accordance with paragraph (f) of this AD before 
the airplane has accumulated 10,000 total flight cycles, or within 
250 flight cycles after June 16, 2006, whichever is later.

New Requirements of This AD

Detailed Inspection of Additional Airplanes

    (g) For Group 2 and Group 3 airplanes identified in Boeing Alert 
Service Bulletin 747-53A2515, Revision 1, dated March 1, 2007: 
Except as provided by paragraphs (h) and (i) of this AD, at the 
applicable time specified in paragraph 1.E of Boeing Alert Service 
Bulletin 747-53A2515, Revision 1, dated March 1, 2007, do a detailed 
inspection of the left and right longeron extension fittings for 
damage and, before further flight, do the corrective action, as 
applicable; by accomplishing all the applicable actions specified in 
the Accomplishment Instructions of the alert service bulletin.

Compliance Times

    (h) Where the alert service bulletin specifies compliance times 
relative to the release date of the alert service bulletin, this AD 
requires compliance at compliance times relative to the effective 
date of this AD.

Repair of Certain Conditions

    (i) If any damage is found during any inspection required by 
this AD and the service bulletin specifies to contact Boeing for 
appropriate action: Before further flight, repair the damage using a 
method approved in accordance with the procedures specified in 
paragraph (k) of this AD.

Credit for Actions Done Using Previous Service Information

    (j) Actions done before the effective date of this AD in 
accordance with Boeing Alert Service Bulletin 747-53A2515, dated 
October 20, 2005, are considered acceptable for

[[Page 45976]]

compliance with the corresponding actions of this AD.

Alternative Methods of Compliance (AMOCs)

    (k)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.
    (2) AMOCs approved previously in accordance with AD 2006-10-04, 
are approved as AMOCs for the corresponding provisions of this AD.
    (3) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.
    (4) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is approved by an 
Authorized Representative for the Boeing Commercial Airplanes 
Delegation Option Authorization Organization who has been authorized 
by the Manager, Seattle ACO, to make those findings. For a repair 
method to be approved, the repair must meet the certification basis 
of the airplane, and the approval must specifically refer to this 
AD.

    Issued in Renton, Washington, on July 30, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-16121 Filed 8-15-07; 8:45 am]

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