
[Federal Register: September 12, 2008 (Volume 73, Number 178)]
[Rules and Regulations]               
[Page 52909-52911]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr12se08-3]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0967; Directorate Identifier 2008-NM-152-AD; 
Amendment 39-15671; AD 2008-19-04]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 777-200 and -300 Series 
Airplanes Equipped With Rolls-Royce Model RB211-TRENT 800 Series 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
Boeing Model 777-200 and -300 series airplanes. This AD requires 
revising the airplane flight manual to include in-flight procedures for 
pilots to follow in certain cold weather conditions and requires fuel 
circulation procedures on the ground when certain conditions exist. 
This AD results from a report of uncommanded reduction in thrust on 
both engines because of reduced fuel flows. We are issuing this AD to 
prevent ice from accumulating in the main tank fuel feed system, which, 
when released, could result in a restriction in the engine fuel system. 
Such a restriction could result in failure to achieve a commanded 
thrust, and consequent forced landing of the airplane.

DATES: This AD is effective September 29, 2008.
    We must receive comments on this AD by November 12, 2008.

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

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the

[[Page 52910]]

Docket Management Facility between 9 a.m. and 5 p.m., Monday through 
Friday, except Federal holidays. The AD docket contains this 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: Margaret Langsted, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone 
(425) 917-6500; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: 

Discussion

    On January 17, 2008, a Boeing Model 777-200 series airplane 
equipped with Rolls-Royce Model RB211 TRENT 895-17 turbofan engines 
crash landed short of the runway at London Heathrow Airport. During 
final approach, the autothrottles commanded an increase in thrust from 
both engines, and the engines initially responded. However, at a height 
of about 720 feet above the ground, the thrust of the right engine 
reduced, and approximately seven seconds later, the thrust on the left 
engine reduced. The uncommanded reduction in thrust on both engines was 
the result of reduced fuel flows. The engine control system detected 
the reduced fuel flows and commanded increased thrust. However, there 
was no appreciable change in the fuel flow to either engine, and the 
airplane crash landed short of the runway.
    The investigation determined that over a long period of low power 
fuel flows and low fuel temperatures associated with cruise flight, ice 
can accumulate in the main tank fuel feed system and then release as a 
result of increased fuel flow when high thrust is commanded. When 
released, the ice could create a restriction within the engine fuel 
system. A restriction in the engine fuel system, if not corrected, 
could result in failure to achieve a commanded thrust, and consequent 
forced landing of the airplane.
    All of the testing and research of this accident has been conducted 
on Boeing Model 777-200 and -300 series airplanes, equipped with Rolls-
Royce Model RB211-TRENT 800 series engines. Initial review of 777 other 
airplane engine combinations has not revealed the same vulnerability to 
the identified unsafe condition.

FAA's Determination and Requirements of This AD

    We are issuing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the(se) same type 
design(s). This AD requires revising the Limitations section of the 
airplane flight manual to include procedures for pilots to follow in 
certain cold weather conditions and requires fuel circulation 
procedures on the ground when certain conditions exist.
    Paragraph (g) of the AD requires that the fuel circulation 
procedures be accomplished by a certified mechanic. We are including 
this requirement because of the complexity of the procedure. We 
recognize that persons other than mechanics who are properly trained 
might also be capable of accomplishing this procedure. Therefore, we 
would be receptive to requests for approval of alternative methods of 
compliance in accordance with paragraph (j) of the AD to allow others 
to accomplish the procedure if the request includes training and 
oversight provisions to ensure that the procedure is accomplished 
properly.

Interim Action

    We consider this proposed AD interim action. If final action is 
later identified, we might consider further rulemaking then.

FAA's Justification and Determination of the Effective Date

    Hazardous amounts of ice might accumulate within the main tank fuel 
feed system under certain conditions, which, when released, could 
result in a restriction in the engine fuel system. Such a restriction 
could result in failure to achieve a commanded thrust, and consequent 
forced landing of the airplane. We have determined that the loss of 
engine thrust was likely due to ice accumulating in the main tank fuel 
feed system during long exposure to cold fuel temperatures and low 
power fuel flows. It is necessary to issue interim mitigating actions 
in order to prevent an additional accident. Because of our requirement 
to promote safe flight of civil aircraft and thus, the critical need to 
assure the proper functioning of the main tank fuel feed system and the 
short compliance time involved with this action, this AD must be issued 
immediately.
    Because an unsafe condition exists that requires the immediate 
adoption of this AD, we find 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

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not provide you with notice and an opportunity to 
provide your comments before it becomes effective. However, we invite 
you to send any written data, views, or arguments about this AD. Send 
your comments to an address listed under the ADDRESSES section. Include 
``Docket No. FAA-2008-0967; Directorate Identifier 2008-NM-152-AD'' at 
the beginning of your comments. We specifically invite comments on the 
overall regulatory, economic, environmental, and energy aspects of this 
AD. We will consider all comments received by the closing date and may 
amend this 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 AD.

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

    This AD will not have federalism implications under Executive Order 
13132. This AD 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.
    For the reasons discussed above, I certify that this AD:

[[Page 52911]]

    (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.
    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.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 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. The FAA amends Sec.  39.13 by adding the following new AD:

2008-19-04 Boeing: Amendment 39-15671. Docket No. FAA-2008-0967; 
Directorate Identifier 2008-NM-152-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective September 29, 
2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 777-200 and -300 series 
airplanes, certificated in any category; equipped with Rolls-Royce 
Model RB211-TRENT 800 series engines.

Unsafe Condition

    (d) This AD results from a report of the uncommanded reduction 
in thrust on both engines because of reduced fuel flows. We are 
issuing this AD to prevent ice from accumulating in the main tank 
fuel feed system, which, when released, could result in a 
restriction in the engine fuel system. Such a restriction could 
result in failure to achieve a commanded thrust, and consequent 
forced landing of the airplane.

Compliance

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

Airplane Flight Manual (AFM) Revision

    (f) Within 10 days after the effective date of this AD, revise 
the Limitations section of the AFM to include the following 
statement. This may be done by inserting a copy of this AD in the 
AFM.

    ``On ground, after refueling, check fuel temperature if fuel 
temperature indication is operative. If fuel temperature is colder 
than 0 degrees C or if fuel temperature indication is inoperative, 
verify that a record exists certifying that the approved fuel 
circulation procedure was performed.
    ``Perform all step climbs using VNAV or maximum climb thrust.
    ``In flight, within 3 hours of top of descent, but not less than 
15 minutes before top of descent, check fuel temperature. If fuel 
temperature is colder than -10 degrees C, perform a step climb using 
maximum climb thrust. If a step climb using maximum climb thrust 
cannot be accomplished, verify cruise speed is set to 0.84 Mach or 
less, and manually advance thrust levers to maximum (autothrottles 
may be overridden). After reaching maximum climb thrust, hold for 10 
seconds or until reaching 0.86 Mach, whichever occurs first. Check 
engines to ensure they have achieved maximum climb thrust and 
operate normally.''

Fuel Circulation Procedure

    (g) As of 10 days after the effective date of this AD: If the 
fuel temperature has not exceeded 0 degrees Celsius during the 
ground turn, before further flight, using the main tank fuel boost 
pumps, pump fuel through the fuel manifold using the high flow mode 
for a minimum of one minute. A certified mechanic must do the fuel 
circulation procedure required by this paragraph using a method 
approved by the Manager, Seattle Aircraft Certification Office 
(ACO), FAA.
    (h) Before further flight after accomplishing the action 
required by paragraph (g) of this AD, make a record in which the 
person accomplishing the procedure certifies that it was 
accomplished in accordance with the approved method, and provide the 
record to the flightcrew. Under the provisions of the Paperwork 
Reduction Act (44 U.S.C. 3501 et seq.), the Office of Management and 
Budget (OMB) has approved the information collection requirements 
contained in this AD and has assigned OMB Control Number 2120-0056.

Special Flight Permit

    (i) Special flight permits, as described in section 21.197 and 
section 21.199 of the Federal Aviation Regulations (14 CFR 21.197 
and 21.199), are not allowed.

Alternative Methods of Compliance (AMOCs)

    (j)(1) The Manager, Seattle ACO, FAA, ATTN: Margaret Langsted, 
Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle ACO, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone 
(425) 917-6500; 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.

Material Incorporated by Reference

    (k) None.

    Issued in Renton, Washington, on September 5, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-21138 Filed 9-11-08; 8:45 am]

BILLING CODE 4910-13-P
