[Federal Register Volume 74, Number 163 (Tuesday, August 25, 2009)]
[Proposed Rules]
[Pages 42807-42810]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-20382]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-0718; Directorate Identifier 2009-NM-025-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for all 
Boeing Model 747 airplanes. This proposed AD would require one-time 
detailed and high frequency eddy current inspections for cracks in the 
wing and horizontal stabilizer side-of-body joints and the fuselage 
skin circumferential splices, and repair if necessary. This proposed AD 
would also require, for certain airplanes, repetitive detailed 
inspections for cracks of the fuselage skin circumferential splices, 
and repair if necessary. This proposed AD results from Boeing analysis 
indicating that the wing and horizontal stabilizer side-of-body joints, 
and the fuselage skin circumferential splices are susceptible to 
fatigue cracking due to high cyclic loads on the airplane. We are 
proposing this AD to detect and correct fatigue cracking at multiple 
adjacent locations in the subject areas, which could connect to form 
large cracks and result in reduced structural integrity leading to 
rapid decompression and consequent loss of control of the airplane.

DATES: We must receive comments on this proposed AD by October 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 proposed 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 [email protected]; 
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

[[Page 42808]]

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-2009-0718; 
Directorate Identifier 2009-NM-025-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.

Discussion

    Boeing analysis indicates that the wing and horizontal stabilizer 
side-of-body joints and the fuselage skin circumferential splices on 
Model 747 airplanes are susceptible to fatigue cracking due to high 
cyclic loads on the airplane. This condition, if not corrected, could 
result in reduced structural integrity leading to rapid decompression 
and consequent loss of control of the airplane.

Related Rulemaking

    On March 24, 2004, we issued AD 2004-07-22, amendment 39-13566 (69 
FR 18250, April 7, 2004), for all Boeing Model 747 series airplanes. (A 
correction of AD AD 2004-07-22 was issued on December 26, 2007 (73 FR 
1052, January 7, 2008), to clarify the AD applicability.) That AD 
supersedes two existing ADs which require that the 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 also 
requires additional and expanded inspections, and repair of cracked 
structure. That AD resulted from a structural re-evaluation that 
identified additional structural elements where, if damage were to 
occur, supplemental inspections may be required for timely detection of 
fatigue cracking. We issued that AD to ensure the continued structural 
integrity of the entire fleet of Model 747 series airplanes.
    On January 29, 2004, we issued AD 2004-03-09, amendment 39-13453 
(69 FR 6542, February 11, 2004), for all Boeing Model 747-100, 747-
100B, 747-100B SUD, 747-200B, 747-200F, 747-200C, 747-300, 747SR, and 
747SP series airplanes. That AD requires repetitive inspections for 
discrepancies of the structure near and common to the upper chord and 
splice fittings of the rear spar of the wing, and repair if necessary. 
That AD also provides for an optional modification that, if 
accomplished, terminates the repetitive inspection requirement, but 
would necessitate eventual post-modification inspections. We issued 
that AD to find and fix fatigue cracking of structure near and common 
to the upper chord and splice fittings of the rear spar of the wing, 
which could result in loss of structural integrity of the airplane.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 747-51A2060, dated 
October 30, 2008. The service bulletin describes procedures for one-
time detailed and open-hole high frequency eddy current (HFEC) 
inspections for cracks in the wing side-of-body (SOB) joint upper and 
lower surfaces; one-time detailed and open-hole HFEC inspections for 
cracks in the horizontal stabilizer SOB joint; one-time surface and 
open-hole HFEC inspections for cracks of the fuselage skin 
circumferential splices; as applicable; and repair if necessary. The 
service bulletin also describes procedures, for certain airplanes, for 
repetitive detailed inspections for cracks of the fuselage skin 
circumferential splices. The service bulletin also allows surface HFEC 
inspections as an option for doing certain open-hole HFEC inspections 
for cracks in the horizontal stabilizer SOB joint surfaces. For 
airplanes on which any crack is found during any inspection, the 
procedures include reporting the crack finding to Boeing and contacting 
Boeing for repair data, and repairing before further flight.
    The compliance times for the inspections are as follows:
     For Groups 1 through 5 airplanes, for the detailed 
inspection of the fuselage skin circumferential splices: Before the 
accumulation of 25,000 total flight cycles, or within 1 year after the 
date on the service bulletin, whichever occurs later. For airplanes on 
which no crack is found, the inspection is repeated within 6,000 flight 
cycles after the initial inspection, and thereafter at intervals not to 
exceed 6,000 flight cycles.
     For Groups 1 through 3 airplanes, for the detailed and 
open-hole HFEC inspections of the wing SOB joint upper and lower 
surfaces; detailed and open-hole HFEC inspections of the horizontal 
stabilizer SOB joint; and surface and open-hole HFEC inspections of the 
fuselage skin circumferential splices are to be done at the later of 
the following times: Before the accumulation of 30,000 total flight 
cycles or 115,000 total flight hours (whichever occurs first), or 
within 1 year after the date on the service bulletin. The service 
bulletin also specifies that operators do not accomplish the 
inspections until the airplane has accumulated at least either 28,500 
total flight cycles or 110,000 total flight hours.
     For Groups 4 through 6 airplanes for the detailed and 
open-hole HFEC inspections of the wing SOB joint upper and lower 
surfaces; detailed and open-hole HFEC inspections of the horizontal 
stabilizer SOB joint; and surface and open-hole HFEC inspections of the 
fuselage skin circumferential splices are to be done at the later of 
the following times: Before the accumulation of 30,000 total flight 
cycles or 135,000 total flight hours (whichever occurs first), or 
within 1 year after the date on the service bulletin. The service 
bulletin also specifies that operators should not accomplish the 
inspections until the airplane has accumulated at least either 28,500 
total flight cycles or 130,000 total flight hours.

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 the same type design. 
This proposed AD would require accomplishing the actions specified in 
the service information described previously, except as discussed under 
``Difference Between the Proposed AD and Service Information.''

Difference Between the Proposed AD and Service Information

    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

[[Page 42809]]

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 might consider further rulemaking then.

Costs of Compliance

    We estimate that this proposed AD would affect 165 airplanes of 
U.S. registry. We also estimate that it would take 2,604 work-hours per 
product to comply with this proposed AD. The average labor rate is $80 
per work-hour. Based on these figures, we estimate the cost of this 
proposed AD to the U.S. operators to be $34,372,800, or $208,320 per 
product.

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 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-2009-0718; Directorate Identifier 2009-NM-
025-AD.

Comments Due Date

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

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to 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, certificated in any 
category.

Subject

    (d) Air Transport Association (ATA) of America Code 51: Standard 
practices/structures.

Unsafe Condition

    (e) This AD results from a Boeing analysis indicating that the 
wing and horizontal stabilizer side-of-body joints, and the fuselage 
skin circumferential splices are susceptible to fatigue cracking due 
to high cyclic loads on the airplane. The Federal Aviation 
Administration is issuing this AD to detect and correct fatigue 
cracking at multiple adjacent locations in the subject areas, which 
could connect to form large cracks and result in reduced structural 
integrity leading to rapid decompression and consequent loss of 
control of the airplane.

Compliance

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

Inspections and Repair if Necessary

    (g) Except as provided by paragraphs (h) and (i) of this AD: At 
the applicable times specified in paragraph 1.E. of Boeing Alert 
Service Bulletin 747-51A2060, dated October 30, 2008, do one-time 
inspections for cracks in the wing and horizontal stabilizer side-
of-body joints, and the fuselage skin circumferential splices; do 
detailed inspections, as applicable, for cracks of the fuselage skin 
circumferential splices; and do all applicable repairs before 
further flight, in accordance with the Accomplishment Instructions 
of Boeing Alert Service Bulletin 747-51A2060, dated October 30, 
2008, except as provided by paragraphs (j) and (k) of this AD. As 
applicable, repeat the detailed inspection for cracks of the 
fuselage skin circumferential splices, at the applicable times 
specified in paragraph 1.E. of Boeing Alert Service Bulletin 747-
51A2060, dated October 30, 2008.

Exceptions to Compliance Times

    (h) Where Boeing Alert Service Bulletin 747-51A2060, dated 
October 30, 2008, specifies a compliance time after ``* * * the date 
on this service bulletin,'' this AD requires compliance within the 
specified compliance time after the effective date of this AD.
    (i) Where Note (a) of Table 2 of paragraph 1.E. of Boeing Alert 
Service Bulletin 747-51A2060, dated October 30, 2008, specifies that 
if a certain modification was done then certain inspections may be 
deferred ``until the post modification inspection period as given in 
Service Bulletin 747-57A2314,'' this AD allows, for airplanes on 
which the modification specified in Boeing Service Bulletin 747-
57A2314 has been done, deferring the inspections specified in Part 2 
of paragraph 3.B., of the Work Instructions of Boeing Alert Service 
Bulletin 747-51A2060, dated October 30, 2008, until the applicable 
post-modification inspection intervals required by paragraph (e) of 
AD 2004-03-09, amendment 39-13453.

Exception to Part 4 Actions

    (j) For Group 6 airplanes identified in Boeing Alert Service 
Bulletin 747-51A2060, dated October 30, 2008: Do the inspections 
specified in Part 4 of paragraph 3.B. of the Work Instructions of 
Boeing Alert Service Bulletin 747-51A2060, dated October 30, 2008, 
in accordance with the procedures specified in paragraph (m) of this 
AD.

Exception to Corrective Actions

    (k) If any crack is found during any inspection required by this 
AD, and Boeing Alert Service Bulletin 747-51A2060, dated October 30, 
2008, specifies to contact Boeing for appropriate action: Before 
further flight, repair using a method approved in accordance with 
the procedures specified in paragraph (m) of this AD.

Reporting Requirement

    (l) At the applicable time specified in paragraph (l)(1) or 
(l)(2) of this AD, submit a report of positive and negative findings 
of cracks found during the inspection required by paragraph (g) of 
this AD to Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. Alternatively, operators may submit reports 
to their Boeing field service representatives. The report must 
contain, as a minimum, the following information: airplane serial 
number, flight cycles at time of discovery, location(s) and extent 
of positive crack findings. Under the provisions of the

[[Page 42810]]

Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the Office of 
Management and Budget (OMB) has approved the information collection 
requirements contained in this AD and has assigned OMB Control 
Number 2120-0056.
    (1) If the inspection was done on or before the effective date 
of this AD: Send the report within 30 days after the effective date 
of this AD.
    (2) If the inspection was done after the effective date of this 
AD: Send the report within 30 days after the inspection is done.

Alternative Methods of Compliance (AMOCs)

    (m)(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; Or, e-mail information 
to [email protected].
    (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 August 7, 2009.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-20382 Filed 8-24-09; 8:45 am]
BILLING CODE 4910-13-P