Document ID: FAA-2008-0162-0003
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Boeing Model 747 Airplanes
Posted Date: 2009-02-20T05:00Z

[Federal Register: February 20, 2009 (Volume 74, Number 33)]
[Proposed Rules]               
[Page 7834-7836]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr20fe09-32]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0612; Directorate Identifier 2008-NM-059-AD]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 747 Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of 
comment period.

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SUMMARY: We are revising an earlier proposed airworthiness directive 
(AD) for all Boeing Model 747 airplanes. The original NPRM would have 
required inspecting for cracks in the left- and right-side Stringer 11 
longeron adjacent to the horizontal stabilizer pivot bulkhead, and 
related investigative and corrective actions if necessary. The original 
NPRM resulted from a report of a crack found in the right-side Stringer 
11 longeron horizontal flange, adjacent to the horizontal stabilizer 
pivot bulkhead, during a routine maintenance inspection. This action 
revises the original NPRM by reducing the compliance times for certain 
airplanes. We are proposing this supplemental NPRM to detect and 
correct fatigue cracking of the longeron, which can propagate and cause 
damage to the adjacent horizontal stabilizer pivot bulkhead. This 
damage could result in loss of structural integrity and consequent 
inability of the bulkhead to carry flight loads, which could adversely 
affect controllability of the airplane.

DATES: We must receive comments on this supplemental NPRM by March 17, 
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, P.O. Box 3707, Seattle, Washington 98124-2207; 
telephone 206-544-9990; fax 206-766-5682; e-mail DDCS@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.

[[Page 7835]]

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-2008-0612; 
Directorate Identifier 2008-NM-059-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

    We issued a notice of proposed rulemaking (NPRM) (the ``original 
NPRM'') to amend 14 CFR part 39 to include an airworthiness directive 
(AD) that would apply to all Boeing Model 747 airplanes. That original 
NPRM was published in the Federal Register on June 6, 2008 (73 FR 
32246). That original NPRM proposed to require inspecting for cracks in 
the left- and right-side Stringer 11 longeron adjacent to the 
horizontal stabilizer pivot bulkhead, and related investigative and 
corrective actions if necessary.

Actions Since Original NPRM Was Issued

    Since we issued the original NPRM, we have reviewed Boeing Service 
Bulletin 747-53A2703, Revision 1, dated September 16, 2008. We referred 
to Boeing Alert Service Bulletin 747-53A2703, dated February 14, 2008, 
as the appropriate source of service information for accomplishing the 
actions specified in the original NPRM. Revision 1 of Boeing Service 
Bulletin 747-53A2703 is essentially the same as Boeing Alert Service 
Bulletin 747-53A2703, dated February 14, 2008. However, the compliance 
times have been reduced for Model 747-400 series airplanes that are 
converted to the Model 747-400 large cargo freighter (LCF) 
configuration in Boeing Service Bulletin 747-53A2703, Revision 1, dated 
September 16, 2008. Boeing analysis shows that airplanes converted to a 
Model 747-400LCF configuration have increased structural loads. Those 
airplanes have been moved from Group 1 to new Groups 2 or 3.
    The reduced compliance times for the inspections are as follows:
     For Group 2 airplanes: Before the accumulation of 16,000 
total flight cycles, or within 1,500 flight cycles after the date on 
the service bulletin, whichever occurs later.
     For Group 3 airplanes: Before the accumulation of 13,500 
total flight cycles, or within 1,500 flight cycles after the date on 
the service bulletin, whichever occurs later.
    The repetitive interval has been reduced to 2,000 flight cycles.

Comment

    We gave the public the opportunity to participate in developing 
this AD. We considered the comment received.

Request To Increase Work Hours in Costs of Compliance Section

    Northwest Airlines (NWA) asks that we increase the work hours 
specified in the Costs of Compliance section in the original NPRM. NWA 
states that the estimate of 3 work hours per airplane, as specified in 
the original NPRM, does not match the work-hour estimate specified in 
Boeing Alert Service Bulletin 747-53A2703, dated February 14, 2008. NWA 
notes that Boeing Alert Service Bulletin 747-53A2703 specifies 6 work 
hours per airplane are necessary to accomplish the recommended 
inspections.
    We do not agree to increase the work-hour estimate specified in the 
original NPRM. The required action in the original NPRM is doing a 
surface high frequency eddy current (HFEC) inspection; the open hole 
HFEC inspection is an on-condition action (related investigative and 
corrective actions) and might not be necessary, depending on the 
findings. We recognize that, in doing the actions required by an AD, 
operators might incur incidental costs in addition to the direct costs. 
The cost analysis in AD rulemaking actions, however, typically does not 
include incidental costs such as the time required to gain access and 
close up, time necessary for planning, or time necessitated by other 
administrative actions. Those incidental costs, which might vary 
significantly among operators, are almost impossible to calculate. We 
also typically do not include the cost of on-condition actions, 
although we recognize that doing the on-condition actions imposes 
additional operational costs. We have not changed the AD in this 
regard.

Explanation of Change to the Original NPRM

    We have added a new paragraph (d) to this supplemental NPRM which 
includes the Air Transport Association of America (ATA) code, and we 
have reidentified subsequent paragraphs accordingly.

FAA's Determination and Proposed Requirements of the Supplemental NPRM

    We are proposing this supplemental NPRM because we evaluated all 
pertinent information and determined an unsafe condition exists and is 
likely to exist or develop on other products of the same type design. 
The change in compliance times described above expands the scope of the 
original NPRM. As a result, we have determined that it is necessary to 
reopen the comment period to provide additional opportunity for the 
public to comment on this supplemental NPRM.

Costs of Compliance

    We estimate that this proposed AD would affect 165 airplanes of 
U.S. registry. We also estimate that it would take 3 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 $39,600, or $240 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:

[[Page 7836]]

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-2008-0612; Directorate Identifier 2008-NM-
059-AD.

Comments Due Date

    (a) We must receive comments by March 17, 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 53: 
Fuselage.

Unsafe Condition

    (e) This AD results from a report of a crack found in the right-
side Stringer 11 longeron horizontal flange, adjacent to the 
horizontal stabilizer pivot bulkhead, during a routine maintenance 
inspection. We are issuing this AD to detect and correct fatigue 
cracking of the longeron, which can propagate and cause damage to 
the adjacent horizontal stabilizer pivot bulkhead. This damage could 
result in loss of structural integrity and consequent inability of 
the bulkhead to carry flight loads, which could adversely affect 
controllability of the airplane.

Compliance

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

Inspection/Related Investigative and Corrective Actions

    (g) Except as provided by paragraph (h) of this AD: At the 
applicable times specified in paragraph 1.E. of Boeing Service 
Bulletin 747-53A2703, Revision 1, dated September 16, 2008, do a 
surface high frequency eddy current (HFEC) inspection for cracks in 
the left- and right-side Stringer 11 longeron exposed surfaces and 
edges between Station 2598 and 2607 adjacent to the horizontal 
stabilizer pivot bulkhead; and do all applicable related 
investigative and corrective actions before further flight, in 
accordance with the Accomplishment Instructions of Boeing Service 
Bulletin 747-53A2703, Revision 1, dated September 16, 2008, except 
as provided by paragraph (h) of this AD.

Exception to Compliance Times

    (h) Where Boeing Service Bulletin 747-53A2703, Revision 1, dated 
September 16, 2008, specifies counting the compliance time from ``* 
* * the date on this service bulletin,'' this AD requires counting 
the compliance time from the effective date of this AD.

Exception to Corrective Actions

    (i) If any crack is found during any inspection required by this 
AD, and Boeing Service Bulletin 747-53A2703, Revision 1, dated 
September 16, 2008, specifies to contact Boeing for appropriate 
action: Before further flight, repair 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, 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 has the authority 
to approve AMOCs for this AD, if requested using the procedures 
found in 14 CFR 39.19.
    (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), 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. E9-3614 Filed 2-19-09; 8:45 am]

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