[Federal Register Volume 65, Number 125 (Wednesday, June 28, 2000)]
[Rules and Regulations]
[Pages 39788-39790]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-16233]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-108-AD; Amendment 39-11803; AD 2000-13-04]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 777-200 and -300 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to all Boeing Model 777-200 and -300 series airplanes, 
that currently requires revising the Limitations Section of the 
Airplane Flight Manual (AFM) to prohibit the dispatch of certain 
airplanes under certain conditions. That amendment also requires 
repetitive inspections to ensure correct operation of the backup 
generators; and, for certain airplanes, a one-time inspection to detect 
damage of the engine external gearbox; and corrective actions, if 
necessary. This amendment continues the AFM and inspection requirements 
and expands certain corrective action requirements. This amendment is 
prompted by reports of inflight shutdowns due to sheared backup 
generator shafts. The actions specified in this AD are intended to 
prohibit the dispatch of an airplane with an engine-mounted backup 
generator having a sheared shaft; and to detect and correct damage to 
the engine, which could result in inflight shutdowns.

DATES: Effective July 13, 2000.
    The incorporation by reference of certain publications, as listed 
in the regulations, was approved previously by the Director of the 
Federal Register as of December 23, 1999 (64 FR 68618, December 8, 
1999).
    Comments for inclusion in the Rules Docket must be received on or 
before August 28, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-108-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 also be sent via the Internet using the 
following address: <a href="/cdn-cgi/l/email-protection#c2fbefa3acafefaba3b0a1adafafa7acb682a4a3a3eca5adb4"><span class="__cf_email__" data-cfemail="734a5e121d1e5e1a1201101c1e1e161d07331512125d141c05">[email protected]</span></a>. Comments sent via the 
Internet must contain ``Docket No. 2000-NM-108-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 this AD 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; or at 
the Office of the Federal Register, 800 North Capitol Street, NW., 
suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Ed Hormel, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate, 
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-2681; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: On November 30, 1999, the FAA issued AD 99-
25-13, amendment 39-11456 (64 FR 68618, December 8, 1999), applicable 
to all Boeing Model 777-200 and -300 series airplanes, to require 
revising the Limitations Section of the Airplane Flight Manual to 
prohibit the dispatch of certain airplanes under certain conditions. 
That AD also requires repetitive inspections to ensure correct 
operation of the backup generators; and, for certain airplanes, a one-
time inspection to detect damage of the engine external gearbox; and 
corrective actions, if necessary.
    A correction of the final rule was published in the Federal 
Register on December 22, 1999 (64 FR 71635, December 23, 1999). That AD 
(AD 99-25-13 C1, amendment 39-11456) corrects incorrect paragraph 
references in AD 99-25-13. That action was prompted by reports of 
inflight shutdowns due to sheared backup generator shafts. The actions 
required by the correction AD are intended to prohibit the dispatch of 
an airplane with an engine-mounted backup generator having a sheared 
shaft; and to detect and correct damage to the engine, which could 
result in inflight shutdowns.

Actions Since Issuance of Previous Rule

    Since the issuance of AD 99-25-13 C1, the FAA has received 
questions from an operator regarding the following corrective action 
procedures:
    <bullet> Boeing Service Letter 777-SL-24-023-B, dated August 16, 
1999, specifies accomplishment of the applicable actions specified in 
both Steps 2.a.(1) and 2.a.(2) of that service letter. However, 
paragraph (d)(1)(ii) in that AD requires the accomplishment of either 
Steps 2.a.(1) or 2.a.(2), as applicable.
    <bullet> Boeing Service Letter 777-SL-24-024, dated August 16, 
1999, specifies accomplishment of the applicable actions specified in 
both Steps 1.a.(1) and 1.a.(2) of that service letter. However, 
paragraph (d)(2) in that AD requires the accomplishment of either Steps 
1.a.(1) or 1.a.(2), as applicable.
    In response to the operator's questions, the FAA has determined 
that it is necessary to require the accomplishment of both of the 
applicable corrective actions specified in paragraph (d)(1)(ii) in that 
AD [cited as paragraph (f)(1)(ii) in this AD] for airplanes equipped 
with certain Rolls-Royce engines, and both of the applicable corrective 
actions specified in paragraph (d)(2) in that AD [cited as paragraph 
(f)(2) of this AD] for airplanes equipped with certain General Electric 
engines.
    In addition, paragraphs (d)(1)(ii) and (d)(2) in that AD should 
have specified that the corrective actions required by those paragraphs 
are specified in certain

[[Page 39789]]

steps ``of the service letter.'' That service letter clarification has 
been added to paragraphs (f)(1)(ii) and (f)(2) of this AD, accordingly.
    Paragraphs (d)(3), (d)(3)(i), and (d)(3)(ii) in that AD are cited 
as paragraphs (d), (d)(1), and (d)(2) of this AD for airplanes equipped 
with certain Pratt & Whitney engines. Other paragraphs of this AD also 
have been reformatted.

Explanation of Requirements of Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of this same type design, this AD 
supersedes AD 99-25-13 C1 to continue to require revising the 
Limitations Section of the Airplane Flight Manual to prohibit the 
dispatch of certain airplanes under certain conditions; repetitive 
inspections to ensure correct operation of the backup generators; and, 
for certain airplanes, a one-time inspection to detect damage of the 
engine external gearbox; and corrective actions, if necessary. This 
amendment also expands the requirements for certain corrective actions.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    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 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 rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2000-NM-108-AD.'' The postcard will be date stamped 
and returned to the commenter.

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.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket.
    A copy of it, if filed, may be obtained from the Rules Docket at 
the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

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

Adoption of the Amendment

    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

    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 removing amendment 39-11456 (64 FR 
71635, December 23, 1999), and by adding a new airworthiness directive 
(AD), amendment 39-11803, to read as follows:

2000-13-04  Boeing: Amendment 39-11803. Docket 2000-NM-108-AD. 
Supersedes AD 99-25-13 C1, Amendment 39-11456.

    Applicability: Model 777-200 and -300 series airplanes equipped 
with Rolls-Royce Trent 800, General Electric GE90, or Pratt & 
Whitney PW4000 series turbofan engines; 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 (h) 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 prohibit dispatch of an airplane with an engine-mounted 
backup generator having a sheared shaft; and to detect and correct 
damage to the engine, which could result in inflight shutdowns; 
accomplish the following:

Restatement of Requirements of AD 99-25-13 C1

Revisions to the Airplane Flight Manual

    (a) For all airplanes: Within 14 days after December 23, 1999 
(the effective date of AD 99-25-13 C1, amendment 39-11456), revise 
the Limitations Section of the FAA-approved Airplane Flight Manual 
(AFM) to include the following information. This may be accomplished 
by inserting a copy of this AD in the AFM.
    Dispatch of the airplane with an engine-mounted backup generator 
having a sheared shaft is prohibited.
    Following replacement of the backup generator on both the left 
and right engines, extended twin-engine operations (ETOPS) flight is 
prohibited until a non-ETOPS flight of at least one hour in duration 
is accomplished.

[[Page 39790]]

Prohibited Servicing or Replacement

    (b) For all airplanes: As of 14 days after December 23, 1999, 
the servicing of both the left and right backup generators or 
replacement of both backup generators with new or serviceable 
components by the same individual prior to the same flight is 
prohibited.

One-Time Actions for Rolls-Royce Engines

    (c) For airplanes equipped with Rolls-Royce Trent 800 series 
turbofan engines: Within 14 days after December 23, 1999, determine 
whether the status message ``ELEC BACKUP GEN L(R)'' and the 
maintenance message ``Backup generator L(R) has a sheared shaft'' 
have occurred within the last 250 flight hours prior to the 
effective date of this AD. If these messages have occurred during 
that time, accomplish follow-on corrective actions, as applicable, 
at the times specified in paragraphs C.1.(c) and D. of Rolls-Royce 
Service Bulletin RB.211-72-C813, Revision 1, dated July 16, 1999, in 
accordance with the procedures specified in the service bulletin.

    Note 2: Boeing Service Letter 777-SL-24-023-B, dated August 16, 
1999, references Rolls-Royce Service Bulletin RB.211-72-C813, 
Revision 1, dated July 16, 1999, as an additional source of service 
information to accomplish certain actions required by this AD.

    Inspections and Corrective Actions: Pratt & Whitney Engines
    (d) For Model 777 series airplanes equipped with Pratt & Whitney 
PW4000 series turbofan engines: Within 14 days after December 23, 
1999, and thereafter prior to each flight, if the status message 
``ELEC BACKUP GEN L(R)'' is active, prior to further flight, inspect 
the Maintenance Access Terminal (MAT) for certain maintenance 
messages indicating a sheared shaft or low oil pressure, in 
accordance with Step 1.a. of Boeing Service Letter 777-SL-24-025, 
dated August 18, 1999.
    (1) If any of the specified maintenance messages is active, 
prior to further flight, remove and replace the backup generator in 
accordance with Airplane Maintenance Manual (AMM) 24-25-01-000-801 
or 24-25-01-400-801, as applicable.
    (2) If the backup generator shaft is found to be sheared, or 
either of the low oil pressure messages are active, prior to further 
flight, accomplish the corrective actions specified in Step 1.a.(1) 
of Boeing Service Letter 777-SL-24-025, dated August 18, 1999, in 
accordance with that service letter.

Flight Test After Replacement of Backup Generators: Pratt & Whitney 
Engines

    (e) For airplanes equipped with Pratt & Whitney PW4000 series 
turbofan engines: As of 14 days after December 23, 1999, following 
any replacement of the backup generator on both the left and right 
engines, accomplish paragraphs (e)(1) and (e)(2) of this AD at the 
times specified in those paragraphs.
    (1) Prior to any ETOPS flight, conduct a non-revenue test flight 
of at least one hour in duration, or a non-ETOPS flight that is 
either a non-revenue or revenue flight of at least one hour in 
duration.
    (2) Prior to further flight after accomplishment of the action 
required by paragraph (e)(1) of this AD: Verify accomplishment of 
the maintenance actions required by paragraphs (d), (d)(1), and 
(d)(2) of this AD, as applicable.

New Requirements of This AD

Inspections and Corrective Actions: Rolls-Royce and General 
Electric Engines

    (f) Within 14 days after the effective date of this AD, and 
thereafter prior to each flight: Accomplish paragraphs (f)(1) or 
(f)(2) of this AD, as applicable.
    (1) For airplanes equipped with Rolls-Royce Trent 800 series 
turbofan engines: Accomplish paragraphs (f)(1)(i) and (f)(1)(ii) of 
this AD.
    (i) Inspect the Electrical Maintenance Page of the engine 
indicating and crew alerting system (EICAS), and perform follow-on 
corrective actions, as applicable, at the times specified in and in 
accordance with the procedures specified in Boeing Service Letter 
777-SL-24-023-B, dated August 16, 1999.
    (ii) If the status message ``ELEC BACKUP GEN L(R)'' is active: 
Prior to further flight, inspect the MAT for certain maintenance 
messages indicating a sheared shaft or low oil pressure, as 
specified in Step 2.a. of Boeing Service Letter 777-SL-24-023-B, 
dated August 16, 1999; and accomplish the corrective actions 
specified in Steps 2.a.(1) and 2.a.(2) of the service letter, as 
applicable, in accordance with that service letter.
    (2) For airplanes equipped with General Electric GE90 series 
turbofan engines: If the status message ``ELEC BACKUP GEN L(R)'' is 
active, prior to further flight, inspect the MAT for certain 
maintenance messages indicating a sheared shaft or low oil pressure, 
as specified in Step 1.a. of Boeing Service Letter 777-SL-24-024, 
dated August 16, 1999; and accomplish the corrective actions 
specified in Steps 1.a.(1) and 1.a.(2) of the service letter, as 
applicable, in accordance with the service letter.

Flight Test After Replacement of Backup Generators: Rolls-Royce and 
General Electric Engines

    (g) For airplanes equipped with Rolls-Royce Trent 800 and 
General Electric GE90 series turbofan engines: As of 14 days after 
the effective date of this AD, following any replacement of the 
backup generator on both the left and right engines, accomplish 
paragraphs (g)(1) and (g)(2) of this AD at the times specified in 
those paragraphs.
    (1) Prior to any ETOPS flight, conduct a non-revenue test flight 
of at least one hour in duration, or a non-ETOPS flight that is 
either a non-revenue or revenue flight of at least one hour in 
duration.
    (2) Prior to further flight after accomplishment of the action 
required by paragraph (g)(1) of this AD: Verify accomplishment of 
the maintenance actions required by paragraph (f)(1) or (f)(2) of 
this AD, as applicable.

Alternative Methods of Compliance

    (h) 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 Aircraft Certification 
Office (ACO), FAA, Transport Airplane Directorate. 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

    (i) 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.

Incorporation by Reference

    (j) Except as provided by paragraphs (a), (d)(1), (e)(1), 
(e)(2), (g)(1), and (g)(2) of this AD, the actions shall be done in 
accordance with Rolls-Royce Service Bulletin RB.211-72-C813, 
Revision 1, dated July 16, 1999; Boeing Service Letter 777-SL-24-
023-B, dated August 16, 1999; Boeing Service Letter 777-SL-24-024, 
dated August 16, 1999; or Boeing Service Letter 777-SL-24-025, dated 
August 18, 1999; as applicable. This incorporation by reference was 
approved previously by the Director of the Federal Register as of 
December 23, 1999 (64 FR 68618, December 8, 1999). Copies may be 
obtained from Boeing Commercial Airplane Group, 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 Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.

Effective Date

    (k) This amendment becomes effective on July 13, 2000.

    Issued in Renton, Washington, on June 21, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-16233 Filed 6-27-00; 8:45 am]
BILLING CODE 4910-13-P


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