Document ID: FAA-2010-0764-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Boeing Co. Model 737-900ER Series Airplanes
Posted Date: 2010-08-10T04:00Z

[Federal Register: August 10, 2010 (Volume 75, Number 153)]
[Proposed Rules]               
[Page 48281-48283]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr10au10-10]                         

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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 48281]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0764; Directorate Identifier 2009-NM-260-AD]
RIN 2120-AA64

 
Airworthiness Directives; The Boeing Company Model 737-900ER 
Series 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 
certain Model 737-900ER series airplanes. This proposed AD would 
require doing a one-time general visual inspection for a keyway in two 
fuel tank access door cutouts, and related investigative and corrective 
actions if necessary. This proposed AD results from reports of cracks 
emanating from the keyway of the fuel tank access hole. We are 
proposing this AD to detect and correct such cracking, which could 
result in the loss of the lower wing skin load path and consequent 
structural failure of the wing.

DATES: We must receive comments on this proposed AD by September 24, 
2010.

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 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.

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: Nancy Marsh, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6440; 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-2010-0764; 
Directorate Identifier 2009-NM-260-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 have received reports of cracks, ranging from 0.02 to 0.380 inch 
in length emanating from the keyway of the fuel tank access hole on the 
wing lower skin between wing rib numbers 8 and 9 on Model 777-200LR and 
777-300ER series airplanes. The fuel tank access door at this location 
has a fuel measuring stick installed, and the keyway is used to ensure 
that the fuel measuring stick is oriented correctly when the fuel tank 
access door is installed. The crack is believed to be the result of 
fatigue due to the position of the keyway. The lower wing skins on 
Model 737-900ER series airplanes have fuel tank access holes with the 
same configuration as that of the affected fuel tank access holes on 
Model 777-300ER series airplanes. The affected fuel tank access holes 
on the Model 737-900ER series airplanes are located between ribs 4 and 
5, between wing stations 180 and 204.25. These fuel tank access holes 
are for fuel tank access doors 531BB and 631BB. Although cracks have 
not yet been reported on any Model 737-900ER series airplanes, damage 
tolerance analysis shows potential for Model 737-900ER series airplanes 
lower wing skins to crack at the noted locations. This condition, if 
not corrected, could result in the loss of the lower wing skin load 
path and consequent structural failure of the wing.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 737-57A1308, 
Revision 1, dated October 1, 2009. The service bulletin describes 
procedures for a general visual inspection for a keyway in the fuel 
tank access door cutout on the left and right wings, and related 
investigative and corrective actions if necessary. The related 
investigative action is a high frequency eddy current inspection for 
cracking of the keyway. The corrective actions include changing the 
profile of the keyway for the fuel tank access door cutout, repairing 
any cracking of the keyway of the access door cutout, and contacting 
Boeing for certain repair instructions and doing the repair.

[[Page 48282]]

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 Bulletin.''

Difference Between the Proposed AD and Service Bulletin

    Boeing Alert Service Bulletin 737-57A1308, Revision 1, dated 
October 1, 2009, 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 the Boeing Commercial Airplanes Organization 
Designation Authorization (ODA), whom we have authorized to make those 
findings.

Other Relevant Rulemaking

    The lower wing skins on Model 777-200LR and 777-300ER series 
airplanes have fuel tank access holes with the same configuration as 
those of the affected fuel tank access holes on the Model 737-900ER 
airplanes. Therefore, Model 777-200LR and 777-300ER series airplanes 
may be subject to the identified unsafe condition. We are considering 
similar rulemaking related to the identified unsafe condition for 
certain Model 777-200LR and 777-300ER series airplanes.

Costs of Compliance

    We estimate that this proposed AD would affect 30 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 $85 per 
work-hour. Based on these figures, we estimate the cost of this 
proposed AD to the U.S. operators to be $7,650, or $255 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:

The Boeing Company: Docket No. FAA-2010-0764; Directorate Identifier 
2009-NM-260-AD.

Comments Due Date

    (a) We must receive comments by September 24, 2010.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to The Boeing Company Model 737-900ER series 
airplanes, certificated in any category, as identified in Boeing 
Alert Service Bulletin 737-57A1308, Revision 1, dated October 1, 
2009.

Subject

    (d) Air Transport Association (ATA) of America Code 57: Wings.

Unsafe Condition

    (e) This AD results from reports of cracks emanating from the 
keyway of the fuel tank access hole. The Federal Aviation 
Administration is issuing this AD to detect and correct such 
cracking, which could result in the loss of the lower wing skin load 
path and consequent structural failure of the wing.

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.

Inspection

    (g) Before the accumulation of 7,500 total flight cycles, or 
within 1,000 flight cycles after the effective date of this AD, 
whichever occurs later, do a one-time general visual inspection for 
a keyway in the fuel tank access door cutouts 531BB and 631BB, in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-57A1308, Revision 1, dated October 1, 2009 
(``the service bulletin'').

    Note 1: For the purposes of this AD, a general visual inspection 
is: ``A visual examination of an interior or exterior area, 
installation, or assembly to detect obvious damage, failure, or 
irregularity. This level of inspection is made from within touching 
distance unless otherwise specified. A mirror may be necessary to 
ensure visual access to all surfaces in the inspection area. This 
level of inspection is made under normally available lighting 
conditions such as daylight, hangar lighting, flashlight, or 
droplight and may require removal or opening of access panels or 
doors. Stands, ladders, or platforms may be required to gain 
proximity to the area being checked.''

    (1) If both access door cutouts do not have a keyway, no further 
action is required by this AD.
    (2) If any access door has a keyway, before the accumulation of 
7,500 total flight cycles, or within 1,000 flight cycles after the 
effective date of this AD, whichever occurs later, do a high 
frequency eddy current (HFEC) inspection for cracking of the keyway, 
in accordance with the Accomplishment Instructions of the service 
bulletin.
    (i) If no cracking is found during the HFEC inspection, before 
further flight, modify the profile of the keyway of the fuel tank 
access door cutout, in accordance with the

[[Page 48283]]

Accomplishment Instructions of the service bulletin.
    (ii) If any cracking is found and the crack is 0.030 inch or 
less in length, before further flight repair the keyway, in 
accordance with the Accomplishment Instructions of the service 
bulletin.
    (iii) If any cracking is found and the crack is greater than 
0.030 inch in length, before further flight, repair the crack using 
a method approved in accordance with the procedures specified in 
paragraph (h) of this AD

Alternative Methods of Compliance (AMOCs)

    (h)(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: Nancy Marsh, Aerospace Engineer, Airframe Branch, ANM-120S, 
FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., 
Renton, Washington 98057-3356; telephone (425) 917-6440; fax (425) 
917-6590. Information may be e-mailed to: 9-ANM-Seattle-ACO-AMOC-
Request@faa.gov.
    (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 the 
Boeing Commercial Airplanes Organization Designation Authorization 
(ODA) that 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, 2010.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2010-19695 Filed 8-9-10; 8:45 am]
BILLING CODE 4910-13-P