[Federal Register Volume 72, Number 241 (Monday, December 17, 2007)]
[Proposed Rules]
[Pages 71277-71279]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-24383]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0270; Directorate Identifier 2007-NM-211-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 757-200, -200PF, and -
200CB Series 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 adopt a new airworthiness directive (AD) 
for certain Boeing Model 757-200, -200PF, and -200CB series airplanes. 
This proposed AD would require doing an ultrasound inspection for 
disbonded tear straps not mechanically fastened to the skin, and 
related investigative and corrective actions, if necessary. This 
proposed AD results from reports indicating that bonded skin panels may 
not have been correctly anodized in phosphoric acid before the tear 
strap doubler was bonded to the skin. We are proposing this AD to 
detect and correct a weak bond between the skin and tear strap. Such 
disbonding could reduce the ability of the skin to resist cracks and 
could adversely affect the structural integrity of the airplane.

DATES: We must receive comments on this proposed AD by January 31, 
2008.

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.

[[Page 71278]]

    For service information identified in this AD, contact Boeing 
Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, 
for the service information identified in this proposed AD.

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: Jason Deutschman, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6449; 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-2007-0270; 
Directorate Identifier 2007-NM-211-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 indicating that bonded skin panels may not 
have been correctly anodized in phosphoric acid before the tear strap 
doubler was bonded to the skin between stations 439 to 900, and 1180 to 
1621, and between stringers 10 left and 10 right, on Boeing Model 757-
200, -200PF, and -200CB series airplanes. The cause of the disbonded 
tear straps has been attributed to a manufacturing process error. A 
weak bond between the skin and tear strap, if not corrected, could 
reduce the ability of the skin to resist cracks and could adversely 
affect the structural integrity of the airplane.

Relevant Service Information

    We have reviewed Boeing Special Attention Service Bulletin 757-53-
0077, Revision 1, dated August 6, 2007. The service bulletin describes 
procedures for doing an ultrasound inspection for disbonded tear straps 
not mechanically fastened to the skin between stations 439 to 900, and 
1180 to 1621, and between stringers 10 left and 10 right, and doing 
applicable related investigative and corrective actions. The related 
investigative actions include doing a high frequency eddy current 
inspection to detect cracks around the fasteners, and doing a low 
frequency eddy current inspection to detect corrosion on the surface, 
as applicable. The corrective actions include installing rivets to 
repair disbonding, and contacting Boeing for crack and/or corrosion 
repair, as applicable.
    The service bulletin also specifies the following compliance times 
for:
     Related investigative actions: Before further flight.
     Corrective actions: Before further flight or within 3,000 
flight cycles after the disbonding is found, depending on the location 
of the disbond.
    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other airplanes 
of this same type design. For this reason, we are proposing this AD, 
which would require accomplishing the actions specified in the service 
information described previously.

Costs of Compliance

    There are about 744 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 487 airplanes of 
U.S. registry. The proposed actions would take about 16 work hours per 
airplane, at an average labor rate of $80 per work hour. Based on these 
figures, the estimated cost of the proposed AD for U.S. operators is 
$623,360, or $1,280 per airplane.

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

[[Page 71279]]

by adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2007-0270; Directorate Identifier 2007-NM-
211-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by January 
31, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 757-200, -200PF, and -200CB 
series airplanes, certificated in any category; as identified in 
Boeing Special Attention Service Bulletin 757-53-0077, Revision 1, 
dated August 6, 2007.

Unsafe Condition

    (d) This AD results from reports indicating that bonded skin 
panels may not have been correctly anodized in phosphoric acid 
before the tear strap doubler was bonded to the skin. We are issuing 
this AD to detect and correct a weak bond between the skin and tear 
strap. Such disbonding could reduce the ability of the skin to 
resist cracks and could adversely affect the structural integrity 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.

Initial Inspection

    (f) At the applicable initial compliance time in paragraph 
(f)(1) or (f)(2) of this AD, do an external ultrasound inspection 
for disbonded tear straps not mechanically fastened to the skin 
between stations 439 to 900, and 1180 to 1621, and between stringers 
10 left and 10 right, in accordance with the Accomplishment 
Instructions of Boeing Special Attention Service Bulletin 757-53-
0077, Revision 1, dated August 6, 2007.
    (1) For airplanes with less than or equal to 21,000 total flight 
cycles: Before the accumulation of 24,000 total flight cycles, but 
no earlier than 18,000 total flight cycles.
    (2) For airplanes with more than 21,000 total flight cycles: 
Within 3,000 flight cycles after the effective date of this AD.

Repetitive Inspection

    (g) If no disbonding is found during the ultrasound inspection 
required by paragraph (f) of this AD, repeat the inspection once 
before 36,000 total flight cycles, but no earlier than 30,000 total 
flight cycles.

Related Investigative and Corrective Actions

    (h) If any disbonding is found during the ultrasound inspection 
required by paragraph (f) or (g) of this AD, do the applicable 
related investigative and corrective actions by accomplishing all 
the actions specified in the Accomplishment Instructions of Boeing 
Special Attention Service Bulletin 757-53-0077, Revision 1, dated 
August 6, 2007, at the applicable compliance time specified in 1.E., 
``Compliance,'' of the service bulletin; except as provided by 
paragraph (i) of this AD.
    (i) If any crack and/or corrosion is found during any inspection 
required by this AD, and Boeing Special Attention Service Bulletin 
757-53-0077, Revision 1, dated August 6, 2007, specifies to contact 
Boeing for appropriate action: Before further flight, repair the 
crack and/or corrosion 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 in 
accordance with 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 appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.
    (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 December 7, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-24383 Filed 12-14-07; 8:45 am]
BILLING CODE 4910-13-P