[Federal Register Volume 73, Number 89 (Wednesday, May 7, 2008)]
[Proposed Rules]
[Pages 25599-25601]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-10059]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0520; Directorate Identifier 2008-NM-018-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 777-200 Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain Boeing Model 777-200 series airplanes. This proposed AD would 
require repetitive inspections for any wrinkle in certain external skin 
panels, and for cracking at the fuselage bulkhead shear tie end 
fastener locations at certain stations of section 48 of the fuselage; 
and doing related investigative and corrective actions if necessary. 
This proposed AD results from a report of cracks found in the external 
skin on the left and right sides of the Section 48 panel of the 
fuselage on two airplanes with skin wrinkles found at two of the 
external crack locations. We are proposing this AD to detect and 
correct wrinkles and cracks in certain external skin panels of Section 
48, which could join together and result in reduced structural 
integrity of support structure for the vertical and horizontal 
stabilizers and inability of the airplane to sustain limit loads.

DATES: We must receive comments on this proposed AD by June 23, 2008.

ADDRESSES: You may send comments by any of the following methods:
    <bullet> Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
    <bullet> Fax: 202-493-2251.
    <bullet> 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.
    <bullet> 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.

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: Duong Tran, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6452; 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-2008-0520; 
Directorate Identifier 2008-NM-018-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 a report of cracks found in the external skin on 
the left and right sides of the section 48 panel of the fuselage on two 
airplanes. There were ten external skin cracks on one airplane with 
22,732 total flight hours and 20,286 total flight cycles; the cracks 
were 0.20 to 0.50 inch in length at

[[Page 25600]]

Stations 2195.75 and 2221.65, between Stringers 6 to 10 on the left and 
right sides. In addition, skin wrinkles 4.5 and 5.0 inches long and 1.0 
inch wide and 0.014 inch deep were found at two of the external skin 
crack locations. A second report indicated that three external skin 
cracks, 0.12 to 0.20 inches in length were found at Station 2195.75, 
above Stringer 7 on the left side, on an airplane with 22,147 total 
flight hours and 19,281 total flight cycles. This condition, if not 
corrected, could result in reduced structural integrity of support 
structure for the vertical and horizontal stabilizers and inability of 
the airplane to sustain limit loads.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 777-53A0051, dated 
November 8, 2007. The alert service bulletin describes procedures for 
repetitive general visual inspections for any wrinkle of the external 
skin at Stations 2195.75, 2221.65, and 2245.70 of the Section 48 panel 
of the fuselage, between stringers 5 and 10 on the left and right 
sides. The service bulletin also describes procedures for repetitive 
high frequency eddy current (HFEC) and detailed inspections for 
cracking at the fuselage bulkhead shear tie end fastener locations of 
the external skin at Stations 2195.75, 2221.65, and 2245.70 of the 
section 48 panel of the fuselage; between stringers 5 and 10 on the 
left and right sides. In addition, the service bulletin describes 
performing related investigative and corrective actions if necessary. 
The corrective actions include removing any skin wrinkle, repairing any 
skin crack, and installing a skin repair if any wrinkle or crack is 
found. The related investigative actions include an internal HFEC 
inspection of the repair doubler edge row fasteners for cracking if a 
skin repair is installed. The service bulletin also recommends 
contacting Boeing for repair data if any crack is found that is 1.0 or 
more inches in length.
    The compliance times for the inspections specified in the service 
bulletin are as follows:
    <bullet> General visual and external HFEC inspections for any 
wrinkle and cracking of the skin panels and bulkhead shear tie end 
fastener locations at Stations 2195.75, 2221.65, and 2245.70 of the 
Section 48 panel of the fuselage, between stringers 5 and 10: Before 
16,000 total flight cycles or within 2,300 flight cycles after the date 
on the service bulletin, whichever occurs later. If no wrinkle or skin 
crack is found, the service bulletin specifies repeating the 
inspections thereafter at intervals not to exceed 4,500 flight cycles.
    <bullet> Internal HFEC inspection of the repair doubler shear tie 
end fasteners and external and internal detailed inspection of the 
tripler, doubler, skin, shear tie, stringer, or fuselage bulkhead 
(fastener locations): Within 30,000 flight cycles after installation of 
the repair.
    <bullet> Internal HFEC inspection of the repair doubler edge row 
fasteners and external and internal detailed inspection of the tripler, 
doubler, skin, shear tie, stringer or fuselage bulkhead within the 
repair area: Before 30,000 total flight cycles, or within 16,000 flight 
cycles after installation of the repair, whichever occurs first. If no 
cracking is found, the service bulletin describes repeating the 
inspections thereafter at intervals not to exceed 16,000 flight cycles. 
If any crack is found, the service bulletin recommends contacting 
Boeing for repair data and repairing.

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 alert 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:
    <bullet> Using a method that we approve; or
    <bullet> 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.

Costs of Compliance

    We estimate that the inspections in this proposed AD would affect 
13 airplanes of U.S. registry. We also estimate that it would take 
about 15 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 
$15,600, or $1,200 per product, per inspection cycle.

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, 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:


[[Page 25601]]


    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-2008-0520; Directorate Identifier 2008-NM-
018-AD.

Comments Due Date

    (a) We must receive comments by June 23, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 777-200 series airplanes, 
certificated in any category; as identified in Boeing Alert Service 
Bulletin 777-53A0051, dated November 8, 2007.

Unsafe Condition

    (d) This AD results from a report of cracks found in the 
external skin on the left and right sides of the section 48 fuselage 
panel on two airplanes with skin wrinkles found at two of the 
external crack locations. We are issuing this AD to detect and 
correct wrinkles and cracks in certain external skin panels of 
section 48, which could join together and result in reduced 
structural integrity of support structure for the vertical and 
horizontal stabilizers and inability of the airplane to sustain 
limit loads.

Compliance

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

Repetitive Inspections/Investigative and Corrective Actions

    (f) At the applicable compliance times specified in paragraph 
1.E., ``Compliance'' of Boeing Alert Service Bulletin 777-53A0051, 
dated November 8, 2007, except as provided by paragraph (g) of this 
AD: Do the applicable inspections for any wrinkle of the external 
skin and for cracking at the fuselage bulkhead shear tie end 
fastener locations at Stations 2195.75, 2221.65, and 2245.70 of the 
section 48 panel of the fuselage, between stringers 5 and 10 on the 
left and right sides; and do all the applicable investigative and 
corrective actions; by doing all of the applicable actions in 
accordance with the Accomplishment Instructions of the service 
bulletin, except as provided by paragraph (h) of this AD. Do all 
applicable investigative and corrective actions before further 
flight. Repeat the applicable inspections thereafter at the 
applicable intervals specified in paragraph 1.E. of the service 
bulletin.

Exception to Compliance Times

    (g) Where Boeing Alert Service Bulletin 777-53A0051, dated 
November 8, 2007, 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

    (h) If any damage beyond the repair limits specified in Boeing 
Alert Service Bulletin 777-53A0051, dated November 8, 2007, is found 
during any inspection required by this AD, and the service bulletin 
specifies to contact Boeing for appropriate action: Before further 
flight, repair the crack using a method approved in accordance with 
the procedures specified in paragraph (i) of this AD.

Alternative Methods of Compliance (AMOCs)

    (i)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, ATTN: Duong Tran, Aerospace Engineer, Airframe Branch, ANM-
120S, FAA, Seattle ACO, 1601 Lind Avenue, SW., Renton, Washington 
98057-3356; telephone (425) 917-6452; 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 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.

    Issued in Renton, Washington, on April 25, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E8-10059 Filed 5-6-08; 8:45 am]
BILLING CODE 4910-13-P