[Federal Register Volume 72, Number 50 (Thursday, March 15, 2007)]
[Proposed Rules]
[Pages 12125-12127]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-4742]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-27560; Directorate Identifier 2006-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 inspections to detect scribe lines and 
cracks of the fuselage skin, lap joints, circumferential butt splice 
strap, and external and internal approved repairs; and related 
investigative/corrective actions if necessary. This proposed AD results 
from reports of scribe lines adjacent to the skin lap joints. We are 
proposing this AD to detect and correct cracks, which could grow and 
cause rapid decompression of the airplane.

DATES: We must receive comments on this proposed AD by April 30, 2007.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
    <bullet> DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
    <bullet> Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
    <bullet> Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, 
Washington, DC 20590.
    <bullet> Fax: (202) 493-2251.
    <bullet> Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for the service information identified in this 
proposed AD.

FOR FURTHER INFORMATION CONTACT: Dennis Stremick, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6450; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed in the ADDRESSES section. Include the docket number ``FAA-2007-
27560; Directorate Identifier 2006-NM-211-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
may visit http://dms.dot.gov.

Examining the Docket

    You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the Docket Management System 
receives them.

Discussion

    We have received reports of scribe lines found adjacent to the skin 
lap joints on Model 757-200 airplanes. The scribe lines appear to have 
been made on the skin when sealant was removed as part of preparation 
of the airplane for repainting. The airplanes had between 13,300 and 
16,800 flight cycles. Although no cracks as a result of scribe lines 
have been reported on Model 757 airplanes, scribe lines have caused 
cracks on other airplanes. Undetected cracking, if not corrected, could 
grow and result in rapid decompression.

Related AD

    This proposed AD is similar to AD 2006-07-12, amendment 39-14539 
(71 FR 16211), March 31, 2006. That AD applies to all Boeing Model 737-
100, -200, -200C, -300, -400, and -500 series airplanes. That AD 
requires a one-time inspection for scribe lines and cracks in the 
fuselage skin at certain lap joints, butt joints, external repair 
doublers, and other areas; and related investigative/corrective actions 
if necessary. That AD resulted from reports of fuselage skin cracks 
adjacent to the skin lap joints on airplanes that had scribe lines.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 757-53A0092, 
Revision 1, dated January 10, 2007. The service bulletin describes 
procedures for removing paint and sealant at the applicable zonal 
locations, and doing detailed inspections to detect scribe lines and 
cracks of the fuselage skin, lap joints, circumferential butt splice 
strap, and external and internal approved repairs. The service bulletin 
specifies repairing scribe lines before further flight, except when a 
limited return to service (LRTS) program for qualifying scribe lines 
would allow return to service for a limited period before scribe lines 
are repaired.
    The LRTS program includes repetitive inspections to detect cracks 
where scribe lines were found. To qualify for an LRTS program, a scribe 
line must meet certain criteria including the total flight cycles on 
the airplane, and the location and extent of the scribe lines.

[[Page 12126]]

The service bulletin specifies contacting Boeing for final repair 
instructions for the LRTS program, which would eliminate the need for 
the repetitive inspections of the LRTS program. The repetitive 
intervals for the LRTS program range from 1,500 to 8,000 flight cycles, 
depending on the location of the scribe lines and the configuration of 
the airplane.
    Each piece of structure susceptible to a scribe line is assigned to 
a zone. Based on criticality of location, the service bulletin 
addresses the most critical areas (zones) first and appropriately 
reduces the compliance requirements for less critical areas. The 
service bulletin has specific instructions for calculating separate 
inspection thresholds. These thresholds are based on (1) fatigue life 
for the identified zonal locations and (2) potential scribe line 
opportunities in an airplane's maintenance history. The compliance 
times for inspecting are 20,000 flight cycles (Zone 1) and 30,000 
flight cycles (Zone 2) after the first scribe opportunity. If a 
maintenance records-based threshold program is not used, however, the 
service bulletin specifies 6,000 flight cycles as the first scribe 
opportunity. Since a scribe line can occur at any time during the 
service life of an airplane and at many locations, the service bulletin 
uses both total flight cycles and structural criticality of locations 
to determine the inspection requirements.

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, except as discussed below.

Differences 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 by using a method that we 
approve, or by 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 
Organization whom we have authorized to make those findings.
    The service bulletin specifies compliance times relative to the 
date of issuance of the service bulletin; however, this proposed AD 
would require compliance before the specified compliance time relative 
to the effective date of the AD.

Costs of Compliance

    There are about 945 airplanes of the affected design in the 
worldwide fleet; of these, about 634 are U.S.-registered airplanes. The 
following table provides the estimated costs for U.S. operators to 
comply with this proposed AD. There are no U.S.-registered airplanes in 
Group 5 or Group 6.

                                                 Estimated Costs
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                                                                                  Number of U.S.-
           Inspections              Work hours     Average labor     Cost per       registered      Fleet cost
                                                   rate per hour     airplane        airplanes
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Group 1.........................             127             $80         $10,160             144      $1,463,040
Group 2.........................             122              80           9,760               6          58,560
Group 3.........................             154              80          12,320              75         924,000
Group 4.........................             128              80          10,240             409       4,188,160
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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 by 
adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2007-27560; Directorate Identifier 2006-NM-
211-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by April 30, 
2007.

[[Page 12127]]

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 Alert Service Bulletin 757-53A0092, Revision 1, dated January 
10, 2007.

Unsafe Condition

    (d) This AD results from reports of scribe lines adjacent to the 
fuselage skin lap joints. We are issuing this AD to detect and 
correct cracks, which could grow and cause rapid decompression 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.

Inspections

    (f) Perform detailed inspections to detect scribe lines and 
cracks of the fuselage skin, lap joints, circumferential butt splice 
strap, and external and internal approved repairs; and perform 
related investigative and corrective actions. Do the actions in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 757-53A0092, Revision 1, dated January 10, 2007, 
except as required by paragraph (g) of this AD. Do the actions 
within the applicable compliance times specified in paragraph 1.E. 
of the service bulletin, except as required by paragraph (h) of this 
AD.

Exceptions to Service Bulletin Specifications

    (g) Where Boeing Alert Service Bulletin 757-53A0092, Revision 1, 
dated January 10, 2007, specifies to contact Boeing for appropriate 
repair instructions, repair using a method approved in accordance 
with the procedures specified in paragraph (j) of this AD.
    (h) Boeing Alert Service Bulletin 757-53A0092, Revision 1, dated 
January 10, 2007, specifies compliance times relative to the date of 
issuance of the service bulletin; however, this proposed AD would 
require compliance before the specified compliance time relative to 
the effective date of the AD.

Credit for Prior Accomplishment

    (i) Inspections done before the effective date of this AD in 
accordance with Boeing Alert Service Bulletin 757-53A0092, dated 
September 18, 2006, are acceptable for compliance with the 
corresponding requirements of paragraph (f) 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) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.
    (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.

    Issued in Renton, Washington, on March 1, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-4742 Filed 3-14-07; 8:45 am]
BILLING CODE 4910-13-P