[Federal Register Volume 66, Number 124 (Wednesday, June 27, 2001)]
[Proposed Rules]
[Pages 34130-34132]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-16054]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-334-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 777-200 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 777-200 
series airplanes. This proposal would require inspections for cracking 
of the web of the horizontal and sloping pressure decks of the fuselage 
and certain stiffener splice angles and stiffener end fittings, and 
repair, if necessary. This proposal would also provide an optional 
preventative modification, which ends the repetitive inspections. This 
action is necessary to find and fix cracking of the web of the 
horizontal and sloping pressure decks, which could result in rapid in-
flight decompression of the airplane. This action is intended to 
address the identified unsafe condition.

DATES: Comments must be received by August 13, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-334-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
<a href="/cdn-cgi/l/email-protection#b68f9bd7d8db9bd8c6c4dbd5d9dbdbd3d8c2f6d0d7d798d1d9c0"><span class="__cf_email__" data-cfemail="e0d9cd818e8dcd8e90928d838f8d8d858e94a0868181ce878f96">[email protected]</span></a>. Comments sent via fax or the Internet must 
contain ``Docket No. 2000-NM-334-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Stan Wood, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2772; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained

[[Page 34131]]

in this action may be changed in light of the comments received.
    Submit comments using the following format:
    <bullet> Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    <bullet> For each issue, state what specific change to the proposed 
AD is being requested.
    <bullet> Include justification (e.g., reasons or data) for each 
request.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2000-NM-334-AD.'' The postcard will be date-stamped 
and returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 2000-NM-334-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report indicating that, during fatigue 
testing of a Boeing Model 777-200 series airplane, fatigue cracking was 
found in the web of the horizontal and sloping pressure decks of the 
fuselage. Stiffener splice angles at body station (BS) 1287 and 
stiffener end fittings at BS 1245 were also found cracked. The cracks 
in the web were found in the radius of the milled pockets of the 
horizontal and sloping pressure decks. Analysis revealed that the 
cracks initiated at the upper surface of the web and propagated down 
through the web to the tangent point of the machined fillet radius of 
the milled pockets. Such cracks, if not found and fixed, could result 
in a rapid in-flight decompression of the airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Special Attention Service 
Bulletin 777-53-0004, dated May 11, 2000, which describes procedures 
for inspections for cracking of the web of the horizontal and sloping 
pressure decks of the fuselage and certain stiffener splice angles and 
stiffener end fittings, and repair or modification, if necessary. The 
subject area has been divided into three inspection areas, and the 
service bulletin recommends a different compliance threshold for each 
inspection area, based on when cracks were found on the test airplane 
during the fatigue test. The three areas are subject to the following 
inspections:
    <bullet> Area 1: Repetitive internal high frequency eddy current 
(HFEC) inspections or, alternatively, external low frequency eddy 
current (LFEC) inspections, of the horizontal pressure deck web.
    <bullet> Area 2: Repetitive internal HFEC inspections or, 
alternatively, repetitive external LFEC inspections of the horizontal 
pressure deck web, repetitive internal HFEC inspections of the sloping 
pressure deck, and repetitive detailed visual inspections of the 
stiffener splice angles at BS 1287 and the stiffener end fittings at BS 
1245.
    <bullet> Area 3: Repetitive internal HFEC inspections or, 
alternatively, repetitive external LFEC inspections of the horizontal 
pressure deck web, and repetitive internal HFEC inspections of the 
sloping pressure deck.
    The service bulletin also describes procedures for repair of 
cracks, as well as a preventative modification, which would eliminate 
the need for the repetitive inspections for the repaired or modified 
areas. The preventative modification described in the service bulletin 
is an option for ending the repetitive inspections on airplanes with no 
cracking. Accomplishment of the actions specified in the service 
bulletin is intended to adequately address the identified unsafe 
condition.
    The effectivity listing of the service bulletin includes Model 777-
200 series airplanes with line numbers 001 through 093. The structure 
of the area subject to this proposed AD has been redesigned on 
airplanes with line numbers 094 and subsequent, so these airplanes are 
not subject to the actions described in the service bulletin.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require accomplishment of the actions specified in 
the service bulletin described previously, except as discussed below.

Difference Between Proposed Rule and Service Bulletin

    Although the service bulletin specifies that the manufacturer may 
be contacted for disposition of certain repair conditions, this 
proposal would require the repair of those conditions to be 
accomplished per a method approved by the FAA, or per data meeting the 
type certification basis of the airplane approved by a Boeing Company 
Designated Engineering Representative who has been authorized by the 
Manager, Seattle Aircraft Certification Office, to make such findings.

Cost Impact

    There are approximately 93 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 27 airplanes of U.S. registry 
would be affected by this proposed AD, that it would take approximately 
36 work hours per airplane to accomplish the proposed inspections, and 
that the average labor rate is $60 per work hour. Based on these 
figures, the cost impact of the proposed AD on U.S. operators is 
estimated to be $58,320, or $2,160 per airplane, per inspection cycle.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the proposed requirements of 
this AD action, and that no operator would accomplish those actions in 
the future if this proposed 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 proposed herein 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. Therefore, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT

[[Page 34132]]

Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new 
airworthiness directive:

Boeing: Docket 2000-NM-334-AD.

    Applicability: Model 777-200 series airplanes, line numbers 001 
through 093 inclusive, certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (e) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To find and fix cracking of the web of the horizontal and 
sloping pressure decks, which could result in rapid in-flight 
decompression of the airplane, accomplish the following:

Initial Inspections

    (a) Do the inspections in paragraphs (a)(1), (a)(2), and (a)(3) 
of this AD at the compliance times specified in those paragraphs. Do 
the inspections according to the Accomplishment Instructions of 
Boeing Special Attention Service Bulletin 777-53-0004, dated May 11, 
2000.
    (1) Area 1: Prior to the accumulation of 16,000 total flight 
cycles, do an internal high frequency eddy current (HFEC) inspection 
or an external low frequency eddy current (LFEC) inspection of the 
horizontal pressure deck web in Inspection Area 1, as defined in the 
service bulletin.
    (2) Area 2: Prior to the accumulation of 31,000 total flight 
cycles, do an internal HFEC inspection or an external LFEC 
inspection of the horizontal pressure deck web, an internal HFEC 
inspection of the sloping pressure deck, and a detailed visual 
inspection of the stiffener end fittings at body station (BS) 1245 
and the stiffener splice angles at BS 1287, in Inspection Area 2, as 
defined in the service bulletin.

    Note 2: For the purposes of this AD, a detailed visual 
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.''

    (3) Area 3: Prior to the accumulation of 46,000 total flight 
cycles, do an internal HFEC inspection or an external LFEC 
inspection of the horizontal pressure deck web, and an internal HFEC 
inspection of the sloping pressure deck, in Inspection Area 3, as 
defined in the service bulletin.

Repetitive Inspections

    (b) Repeat the inspections in paragraph (a) of this AD at least 
every 2,500 flight cycles for areas inspected using the HFEC or 
detailed visual inspection method, or at least every 1,000 flight 
cycles for areas inspected using the LFEC inspection method, until 
paragraph (d) of this AD is done.

Corrective Actions

    (c) If any cracking is found during any inspection required by 
paragraph (a) or (b) of this AD: Before further flight, repair the 
affected area according to Boeing Special Attention Service Bulletin 
777-53-0004, dated May 11, 2000; except, where the service bulletin 
says to contact Boeing for repairs, repair per a method approved by 
the Manager, Seattle Aircraft Certification Office (ACO), FAA; or 
per data meeting the type certification basis of the airplane 
approved by 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 by the Manager, Seattle 
ACO, as required by this paragraph, the Manager's approval letter 
must specifically reference this AD. Repair according to this 
paragraph ends the repetitive inspections required by paragraph (b) 
of this AD for the repaired area.

Optional Preventative Modification

    (d) Modification of Inspection Areas 1, 2, and 3, according to 
Boeing Special Attention Service Bulletin 777-53-0004, dated May 11, 
2000, ends the repetitive inspections required by paragraph (b) of 
this AD for the modified area.

Alternative Methods of Compliance

    (e) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle ACO. Operators shall submit 
their requests through an appropriate FAA Principal Maintenance 
Inspector, who may add comments and then send it to the Manager, 
Seattle ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (f) Special flight permits may be issued in accordance with 
Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 
21.197 and 21.199) to operate the airplane to a location where the 
requirements of this AD can be accomplished.


    Issued in Renton, Washington, on June 20, 2001.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-16054 Filed 6-26-01; 8:45 am]
BILLING CODE 4910-13-U


</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>