[Federal Register Volume 69, Number 186 (Monday, September 27, 2004)]
[Rules and Regulations]
[Pages 57636-57638]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-21272]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-263-AD; Amendment 39-13800; AD 2004-19-06]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 767-200, -300, and -300F 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to all Boeing Model 767-200, -300, and -300F series 
airplanes, that requires inspections to detect cracking or corrosion of 
the fail-safe straps between the side fitting of the rear spar bulkhead 
at body station 955 and the skin; and follow-on/corrective actions. 
This action is necessary to detect and correct fatigue cracking or 
corrosion of the fail-safe straps, which could result in cracking of 
adjacent structure and consequent reduced structural integrity of the 
fuselage. This action is intended to address the identified unsafe 
condition.

DATES: Effective November 1, 2004.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of November 1, 2004.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules 
Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the National 
Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, call (202) 741-6030, or go to: 
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

FOR FURTHER INFORMATION CONTACT: Suzanne Masterson, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6441; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to all Boeing Model 767-200, -300, 
and -300F series airplanes was published in the Federal Register on 
March 5, 2004 (69 FR 10364). That action proposed to require 
inspections to detect cracking or corrosion of the fail-safe straps 
between the side fitting of the rear spar bulkhead at body station 955 
and the skin; and follow-on/corrective actions.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Request To Withdraw Notice of Proposed Rulemaking (NPRM)

    One commenter requests that the NPRM be withdrawn. The commenter 
states that none of the reported incidents described in the Discussion 
section of the NPRM can be attributed completely to fatigue. The 
commenter also states that all data to date that suggest this is a 
fatigue issue are flawed by the fact that there have been three 
separate contributing factors--corrosion, surface damage, and fretting/
small gouging.
    The commenter has inspected 43 airplanes and found only one case of 
cracking, which was the result of surface damage during installation of 
the fail-safe strap in the factory. The commenter discovered the damage 
during normal routine maintenance, using an item currently in the 
maintenance program, and believes that these standard inspections are 
sufficient to maintain the continued safety of the airplanes. The 
commenter also points out that this airplane and the second airplane 
referred to in the Background section of Boeing Alert Service Bulletin 
767-53A0100, dated September 26, 2002 (referenced in the AD as the 
appropriate source of service bulletin for the required actions), have 
early line numbers and ``were [essentially] hand built.'' The commenter 
contends that if this is truly a fatigue issue, there would have been 
at least one other occurrence

[[Page 57637]]

of fatigue cracking in the 20-plus years that the fleet has been 
operating. The commenter also notes that Boeing has acknowledged that 
no cracking was found on its fatigue test article that was tested for 
100,000 flight cycles.
    We do not agree that the NPRM should be withdrawn. It was not our 
intention in the Discussion section of the NPRM to imply that the crack 
findings were attributed completely to fatigue. Because of the critical 
function of the fail-safe strap, we find that inspections are necessary 
to detect cracking or corrosion, regardless of the mode by which the 
crack initiates. Since the issuance of the NPRM, we have received two 
additional reports of cracks in the fail-safe strap: one report for an 
airplane that had accumulated 31,809 total flight cycles, and one 
report from full-scale fatigue testing on a 767 test article. The 
cracks on the fatigue test article were hidden and were not detected 
until the joint was disassembled. We have determined that the existing 
routine maintenance inspections are not sufficient to detect cracked 
fail-safe straps in a timely, reliable manner. Therefore, this AD is 
appropriate and warranted.

Request To Delay Issuance of AD

    One commenter requests the final rule not be issued until the lack 
of available replacement straps is resolved. The commenter states that 
the strap is not repairable at this time. The commenter also states 
that the airplane manufacturer is working on potential repairs and an 
analysis to determine if the replacement strap should be strengthened 
from the original design. The study should be completed by April 15, 
2004.
    We do not agree that the strap is not repairable. All airplanes on 
which cracked or corroded straps were found have been successfully 
repaired with new fail-safe straps, which indicates to us that future 
crack findings can be successfully repaired. The airplane manufacturer 
has informed us that the commenter received preliminary information 
about the study, and that the study is not completed yet. In light of 
the critical nature of the identified unsafe condition, we do not 
consider that delaying this action until after the airplane 
manufacturer develops either an easier repair or an improved strap 
design is warranted. However, under the provisions of paragraph (c) of 
the final rule, we may consider requests for approval of an alternative 
method of compliance if sufficient data are submitted to substantiate 
that such a design change would provide an acceptable level of safety.

Request To Correct Information in the Service Bulletin

    One commenter requests the following changes to Boeing Alert 
Service Bulletin 767-53A0100:
    1. Mark the area of interest (5-inch radius) on figure 2 of the 
service bulletin, or add a new photo to the photos already posted on 
Boeing's Web site under 767-FTD-53-02004 article and refer to the new 
photo or article in the NPRM. The commenter believes that the 
instructions in step 1 of figure 2 are too general for the complexity 
of the structure.
    We partially agree with the commenter. We agree that the structure 
is complex; however, the intent of the service bulletin is to determine 
whether cracks have begun to propagate in adjacent structure due to the 
existence of a crack in the fail-safe straps. The service bulletin 
defines the extent of the adjacent structure to be inspected as 
``within 5 inches of the area of the typical crack area,'' as shown in 
Detail A of figure 2. This definition applies to the structure that is 
visible after doing the access procedures in the Work Instructions of 
the service bulletin. We have determined that the inspection is 
possible without further clarification. No change to the final rule is 
necessary in this regard.
    2. Revise step 2 of the Work Instructions of the service bulletin 
to read, ``Open the Main Landing Gear (MLG) doors * * *'' instead of 
``Open the Main Landing Green (MGL) door. * * *'' Revise steps 2 and 8 
to refer to 767 Airplane Maintenance Manual (AMM) 32-12-00, not 32-00-
20.
    We partially agree. We agree with the commenter that the word 
``green'' in the service bulletin is incorrect. We also agree that the 
767 AMM 32-00-20 does not include instructions for opening the MLG 
doors. However, the correct reference is 767 AMM 32-00-15, not 767 AMM 
32-12-00 as suggested by the commenter. 767 AMM 32-00-15, which is 
referred to in steps 3 and 7 of the Work Instructions, describes 
procedures for opening and closing the MLG doors using the ground 
release lever before installing the MLG door locks and after removing 
them. Boeing has no plans at this time to revise the service bulletin 
to fix these errors. Therefore, we have added a note in the final rule 
to point out the errors in the service bulletin.

Conclusion

    After careful review of the available data, including the comments 
noted above, we have determined that air safety and the public interest 
require the adoption of the rule as proposed.

Interim Action

    This is considered to be interim action until final action is 
identified, at which time we may consider further rulemaking.

Cost Impact

    There are approximately 833 airplanes of the affected design in the 
worldwide fleet. We estimate that 354 airplanes of U.S. registry will 
be affected by this AD, that it will take approximately 2 work hours 
per airplane to accomplish the required inspections, and that the 
average labor rate is $65 per work hour. Based on these figures, the 
cost impact of the AD on U.S. operators is estimated to be $46,020, or 
$130 per airplane, per inspection cycle.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the requirements of this AD 
action, and that no operator would accomplish those actions in the 
future if this AD were not adopted. The cost impact figures discussed 
in AD rulemaking actions represent only the time necessary to perform 
the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

Regulatory Impact

    The regulations adopted herein will 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. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under 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. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

[[Page 57638]]

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. Section 39.13 is amended by adding the following new airworthiness 
directive:

2004-19-06 Boeing: Amendment 39-13800. Docket 2002-NM-263-AD.

    Applicability: All Model 767-200, -300, and -300F series 
airplanes, certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To detect and correct fatigue cracking or corrosion of the fail-
safe straps, which could result in cracking of adjacent structure 
and consequent reduced structural integrity of the fuselage, 
accomplish the following:

Inspections and Follow-On/Corrective Actions

    (a) Except as provided by paragraph (b) of this AD, prior to the 
accumulation of 15,000 total flight cycles, or within 3,000 flight 
cycles after the effective date of this AD, whichever occurs later, 
perform a detailed inspection and eddy current inspection to detect 
cracking or corrosion of the fail-safe straps between the side 
fitting of the rear spar bulkhead at BS 955 and the skin, per Figure 
2 of the Accomplishment Instructions of Boeing Alert Service 
Bulletin 767-53A0100, dated September 26, 2002.

    Note 1: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as mirror, 
magnifying lenses, etc., may be used. Surface cleaning and elaborate 
access procedures may be required.''

    (1) If no crack or corrosion is found, repeat the inspections 
thereafter at intervals not to exceed 6,000 flight cycles or 36 
months, whichever occurs first.
    (2) If any crack or corrosion is found, before further flight, 
repair per a method approved by the Manager, Seattle Aircraft 
Certification Office (ACO), FAA; or a Boeing Company Designated 
Engineering Representative who has been authorized by the Manager, 
Seattle ACO, to make such findings. For a repair method to be 
approved, the approval must specifically reference this AD.
    (b) For airplanes on which the fail-safe strap has been replaced 
before the effective date of this AD: Do the actions required by 
paragraph (a) of this AD within 12,000 flight cycles after 
accomplishing the replacement.

    Note 2: Steps 2 and 8 of the Work Instructions of Boeing Alert 
Service Bulletin 767-53A0100, dated September 26, 2002, refer 
incorrectly to 767 Airplane Maintenance Manual (AMM) 32-00-20 for 
opening the MLG doors; the correct reference is 767 AMM 32-00-15, 
which is referred to in steps 3 and 7 of the Work Instructions. Step 
2 also should state ``Open Main Landing Gear (MLG) doors'' instead 
of ``Open Main Landing Green (MLG) doors.''

Alternative Methods of Compliance

    (c)(1) In accordance with 14 CFR 39.19, the Manager, Seattle 
ACO, FAA, is authorized to approve alternative methods of compliance 
(AMOCs) for this AD.
    (2) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is approved by a 
Boeing Company Designated Engineering Representative who has been 
authorized by the Manager, Seattle ACO, to make such findings.

Incorporation by Reference

    (d) Unless otherwise specified in this AD, the actions shall be 
done in accordance with Boeing Alert Service Bulletin 767-53A0100, 
dated September 26, 2002. This incorporation by reference was 
approved by the Director of the Federal Register in accordance with 
5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 
98124-2207. Copies may be inspected at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the 
National Archives and Records Administration (NARA). For information 
on the availability of this material at NARA, call (202) 741-6030, 
or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

Effective Date

    (e) This amendment becomes effective on November 1, 2004.

    Issued in Renton, Washington, on September 13, 2004.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-21272 Filed 9-24-04; 8:45 am]
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