
[Federal Register: February 23, 2009 (Volume 74, Number 34)]
[Proposed Rules]               
[Page 8034-8036]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr23fe09-9]                         

========================================================================
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 8034]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0136; Directorate Identifier 2008-NM-171-AD]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 747 Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain Boeing Model 747 airplanes. This proposed AD would require 
repetitive inspections for cracking of the fuselage frames in section 
41, and corrective actions if necessary. This proposed AD results from 
reports of cracking in fuselage frames made of 2024 aluminum alloy that 
were installed during previous modification of the frames in section 41 
and during production. We are proposing this AD to detect and correct 
frame cracks, which could result in cracking of the adjacent fuselage 
skin and consequent rapid decompression of the airplane.

DATES: We must receive comments on this proposed AD by April 9, 2009.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://
www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     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.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    For service information identified in this AD, contact Boeing 
Commercial Airplanes, Attention: Data & Services Management, P.O. Box 
3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-544-5000, 
extension 1, fax 206-766-5680; e-mail me.boecom@boeing.com; Internet 
https://www.myboeingfleet.com. You may review copies of the referenced 
service information at the FAA, Transport Airplane Directorate, 1601 
Lind Avenue, SW., Renton, Washington. For information on the 
availability of this material at the FAA, call 425-227-1221 or 425-227-
1152.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Office (telephone 800-647-5527) is in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

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 send any written relevant data, views, or 
arguments about this proposed AD. Send your comments to an address 
listed under the ADDRESSES section. Include ``Docket No. FAA-2009-0136; 
Directorate Identifier 2008-NM-171-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://
www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Other Related Rulemaking

    On January 16, 1990, we issued AD 90-06-06, amendment 39-6490 (55 
FR 8374, March 7, 1990), for certain Boeing Model 747 airplanes. That 
AD requires incorporation of certain structural modifications. That AD 
resulted from reports of incidents involving fatigue cracking and 
corrosion in transport category airplanes that are approaching or have 
exceeded their design life goal. These incidents jeopardized the 
airworthiness of the affected airplanes. We issued that AD to correct 
degradation in the structural capabilities of the affected airplanes. 
The requirements in that AD reflect the FAA's decision that long-term 
continued operational safety should be ensured by actual modification 
of the airframe rather than repetitive inspection.
    On December 26, 2007, we issued AD 2004-07-22 R1, amendment 39-
15326 (73 FR 1052, January 7, 2008), for certain Boeing Model 747 
airplanes. That AD requires that the FAA-approved maintenance 
inspection program be revised to include inspections that will give no 
less than the required damage tolerance rating for each structural 
significant item, and repair of cracked structure. That AD resulted 
from a report of incidents involving fatigue cracking in transport 
category airplanes that are approaching or have exceeded their design 
service objective. We issued that AD to ensure the continued structural 
integrity of all 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.

Discussion

    We have received reports of cracking in fuselage frames made of 
2024 aluminum alloy material that were installed during previous 
modification of frames in section 41 required by AD 90-06-06. One crack 
was in the frame web at body station 340, at a fastener location common 
to the upper chord of the upper deck floor beams. The other crack was 
in the frame web and doubler at body station 420 and was also at a 
fastener location common to the upper deck floor beams. The frame crack 
in body station 340 was found 9,757 flight

[[Page 8035]]

cycles after the 2024 aluminum alloy frame was installed during 
modification of the frames in section 41. The frame crack in body 
station 420 was found 6,441 flight cycles after the 2024 aluminum alloy 
frame was installed during modification of the frames in section 41. 
This condition, if not corrected, could result in cracking of the 
adjacent fuselage skin and consequent rapid decompression of the 
airplane.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletins 747-53A2732 and 
747-53A2753, both dated August 28, 2008. Boeing Alert Service Bulletins 
747-53A2732 and 747-53A2753, both dated August 28, 2008, describe 
procedures for repetitive internal detailed inspections for cracking of 
the fuselage frames in section 41, and corrective actions if necessary. 
Boeing Alert Service Bulletins 747-53A2732 and 747-53A2753, both dated 
August 28, 2008, also describe procedures for an optional special 
detailed inspection behind the flight engineers panel on the upper deck 
and the P14 and P15 electrical terminal panels using a borescope. The 
corrective actions include repairing any crack found during any 
inspection in accordance with the applicable Work Instructions, or by 
contacting Boeing for repair data.
    The compliance times for the initial inspections specified in 
Boeing Alert Service Bulletin 747-53A2732 range from before the 
accumulation of 10,000 or 20,000 flight cycles depending on airplane 
configuration and location since modification of the frames in section 
41 was done, or for airplanes on which 2024 aluminum alloy material was 
installed in production, 20,000 total flight cycles, or within 1,500 
flight cycles after the date on this service bulletin; whichever occurs 
latest. The inspections must be repeated at intervals not to exceed 
3,000 or 6,000 flight cycles, as applicable.
    The compliance times for the initial inspections specified in 
Boeing Alert Service Bulletin 747-53A2753 range from before the 
accumulation of 15,000 or 30,000 total flight cycles depending on 
airplane configuration, or within 1,000 flight cycles after the date on 
this service bulletin, whichever occurs later. If no cracks are found 
or the cracks have been repaired, the inspections must be repeated at 
intervals not to exceed 2,400 or 3,000 flight cycles, as applicable.

FAA's Determination and Requirements of This Proposed AD

    We are proposing this AD because we evaluated all relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of these same type 
designs. This proposed AD would require accomplishing the actions 
specified in the service information described previously, except as 
discussed under ``Differences Between the Proposed AD and Alert Service 
Bulletins.''

Differences Between the Proposed AD and Alert Service Bulletins

    Boeing Alert Service Bulletins 747-53A2732 and 747-53A2753, both 
dated August 28, 2008, specify that you may contact the manufacturer 
for instructions on how to repair certain conditions, but this proposed 
AD requires you to repair 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 Delegation Option Authorization Organization who has 
been authorized by the FAA to make those findings.

Costs of Compliance

    We estimate that this proposed AD would affect 165 airplanes of 
U.S. registry. The following table provides the estimated costs for 
U.S. operators to comply with this proposed AD.

                                                                 Table--Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                     Average
                                            Work      labor                                Number of U.S-
               Inspection                  hours     rate per       Cost per product         registered                      Fleet cost
                                                       hour                                   airplanes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Boeing Alert Service Bulletin 747-              50        $80  Up to $4,000, per                       94  Up to $376,000, per inspection cycle.
 53A2732, Part 1.                                               inspection cycle.
Boeing Alert Service Bulletin 747-             650         80  Up to $52,000, per                      94  Up to $4,888,000, per inspection cycle.
 53A2732, Part 2.                                               inspection cycle.
Boeing Alert Service Bulletin 747-               6         80  $480, per inspection cycle              94  Up to $45,120, per inspection cycle.
 53A2732, Part 3.
Boeing Alert Service Bulletin 747-              51         80  Up to $4,080, per                       94  Up to $383,520, per inspection cycle.
 53A2732, Part 4.                                               inspection cycle.
Boeing Alert Service Bulletin 747-              11         80  Up to $880, per inspection              94  Up to $82,720, per inspection cycle.
 53A2732, Part 5.                                               cycle.
Boeing Alert Service Bulletin 747-              52         80  Up to $4,160, per                       94  Up to $391,040, per inspection cycle.
 53A2732, Part 6.                                               inspection cycle.
Boeing Alert Service Bulletin 747-              13         80  Up to $1,040, per                       94  Up to $97,760, per inspection cycle.
 53A2732, Part 7.                                               inspection cycle.
Boeing Alert Service Bulletin 747-              54         80  Up to $4,320, per                       94  Up to $406,080, per inspection cycle.
 53A2732, Part 8.                                               inspection cycle.
Boeing Alert Service Bulletin 747-             244         80  Up to $19,520, per                      71  Up to $1,385,920, per inspection cycle.
 53A2753.                                                       inspection cycle.
--------------------------------------------------------------------------------------------------------------------------------------------------------

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.

[[Page 8036]]

Regulatory Findings

    We 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 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. 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.
    You can find our regulatory evaluation and the estimated costs of 
compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, 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 FAA amends Sec.  39.13 by adding the following new AD:

Boeing: Docket No. FAA-2009-0136; Directorate Identifier 2008-NM-
171-AD.

Comments Due Date

    (a) We must receive comments by April 9, 2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 747 airplanes, certificated 
in any category, as specified in paragraph (c)(1) or (c)(2) of this 
AD, as applicable.
    (1) Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-
200C, 747-200F, 747-300, 747SR, and 747SP series airplanes, as 
identified in Boeing Alert Service Bulletin 747-53A2732, dated 
August 28, 2008.
    (2) Boeing Model 747-400, 747-400D, and 747-400F series 
airplanes, as identified in Boeing Alert Service Bulletin 747-
53A2753, dated August 28, 2008.

Subject

    (d) Air Transport Association (ATA) of America Code 53: 
Fuselage.

Unsafe Condition

    (e) This AD results from reports of cracking in fuselage frames 
made of 2024 aluminum alloy that were installed during previous 
modification of the frames in section 41 and during production. We 
are issuing this AD to detect and correct frame cracks which could 
result in cracking of the adjacent fuselage skin and consequent 
rapid decompression of the airplane.

Compliance

    (f) Comply with this AD within the compliance times specified, 
unless already done.

Repetitive Inspections and Corrective Actions

    (g) At the applicable compliance time specified in paragraph 
1.E., ``Compliance,'' of Boeing Alert Service Bulletin 747-53A2732 
or 747-53A2753, both dated August 28, 2008, as applicable, do the 
detailed inspection for cracking of the fuselage frames in section 
41, and do all applicable corrective actions, by accomplishing all 
the actions specified in the Accomplishment Instructions of Boeing 
Alert Service Bulletin 747-53A2732 or 747-53A2753, both dated August 
28, 2008, as applicable; except as provided by paragraphs (g) and 
(h) of this AD. Repeat the inspection at intervals not to exceed 
those specified in paragraph 1.E. of Boeing Alert Service Bulletin 
747-53A2732 or 747-53A2753, both dated August 28, 2008, as 
applicable. If any crack is found, do all corrective actions before 
further flight.

    Note 1: As specified in Boeing Alert Service Bulletins 747-
53A2732 and 747-53A2753, both dated August 28, 2008, an optional 
special detailed inspection behind the P14 and P15 electrical 
terminal panels using the borescope may be done.

    (h) Where Boeing Alert Service Bulletins 747-53A2732 and 747-
53A2753, both dated August 28, 2008, recommend an initial inspection 
threshold relative to the date on Boeing Alert Service Bulletins 
747-53A2732 and 747-53A2753, both dated August 28, 2008; this AD 
requires the initial inspection threshold relative to the effective 
date of this AD.
    (i) If any crack is found during any inspection required by this 
AD, and Boeing Alert Service Bulletins 747-53A2732 and 747-53A2753, 
both dated August 28, 2008, specify to contact Boeing for 
appropriate action: Before further flight, repair the cracking using 
a method approved in accordance with the procedures specified in 
paragraph (j) of this AD.

Alternative Methods of Compliance (AMOCs)

    (j)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19. Send information to 
Attn: Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, 
Seattle ACO, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; 
telephone (425) 917-6437; fax (425) 917-6590.
    (2) 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 principal maintenance inspector (PMI) or 
principal avionics inspector (PAI), as appropriate, or lacking a 
principal inspector, your local Flight Standards District Office. 
The AMOC approval letter must specifically reference this AD.
    (3) 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 January 30, 2009.
Stephen P. Boyd,
Assistant Manager, Transport Airplane Directorate, Aircraft 
Certification Service.
[FR Doc. E9-3771 Filed 2-20-09; 8:45 am]

BILLING CODE 4910-13-P
