[Federal Register Volume 71, Number 160 (Friday, August 18, 2006)]
[Proposed Rules]
[Pages 47754-47756]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-13649]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-25609; Directorate Identifier 2005-NM-263-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Boeing Model 777-200 and -300 series airplanes. This 
proposed AD would require revising the airplane flight manual to 
provide the flightcrew with new ground procedures for shedding core ice 
during long taxi periods in freezing fog. For airplanes unable to 
perform the shedding procedure after prolonged taxiing in freezing fog, 
this proposed AD would require certain investigative and corrective 
actions. This proposed AD results from reports of engine surges and 
internal engine damage due to ice accumulation during extended idle 
thrust operation in ground fog icing conditions. We are proposing this 
AD to prevent internal engine damage due to ice accumulation and 
shedding, which could cause a shutdown of both engines, and result in 
loss of control of the airplane.

DATES: We must receive comments on this proposed AD by October 2, 2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, 
Washington, DC 20590.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle,

[[Page 47755]]

Washington 98124-2207, for the service information identified in this 
proposed AD.

FOR FURTHER INFORMATION CONTACT: Margaret Langsted, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone 
(425) 917-6500; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed in the ADDRESSES section. Include the docket number ``FAA-2006-
25609; Directorate Identifier 2005-NM-263-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
may visit http://dms.dot.gov.

Examining the Docket

    You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the Docket Management System 
receives them.

Discussion

    We have received reports indicating that internal engine damage has 
occurred on certain Airbus Model A330-243, -341, -342, and -343 
airplanes equipped with Rolls-Royce RB211 TRENT 700 engines. 
Investigations have revealed that the engines were damaged due to 
extended idle thrust operations in severe ground fog icing conditions 
in very low outside air temperatures and freezing fog. It was 
determined that sufficient ice built upon the stationary surfaces of 
the engine core and heat transfer from increasing the thrust for 
takeoff caused the ice to shed, which then impacted and damaged the 
blades of the compressor. Engine damage due to ice accumulation and 
shedding, if not corrected, could result in a dual engine shutdown and 
loss of control of the airplane.

Similar Engine Models

    Boeing Model 777-200 and -300 series airplanes equipped with Rolls-
Royce RB211 TRENT 800 engines have a similar compressor design to the 
Rolls-Royce RB211 TRENT 700 engines installed on certain Airbus Model 
A330-243, -341, -342, and -343 airplanes. Therefore, those Boeing Model 
777-200 and -300 series airplanes equipped with Rolls-Royce RB211 TRENT 
800 engines may be subject to the same unsafe condition.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other airplanes 
of this same type design. For this reason, we are proposing this AD, 
which would require revising the AFM to provide the flightcrew with new 
ground procedures for shedding core ice during long taxi periods in 
freezing fog as described previously. Additionally, we are proposing 
that, if takeoff is not accomplished during ground operations in 
freezing fog within 60 minutes total taxi time, before further flight, 
the engines must be manually de-iced in accordance with tasks 12-33-03-
600-803 and 12-33-03-600-804 of Chapter 12-33-03 of the Airplane 
Maintenance Manual (AMM). We are also proposing to require that, if the 
core ice shedding procedure is not accomplished within 45 minutes total 
taxi time in freezing fog, but takeoff can be achieved within 60 
minutes total taxi time, that a borescope inspection for damage to the 
engine compressors be accomplished within 10 flights of that takeoff. 
Any repair must be performed before further flight. One acceptable 
method of accomplishing the borescope inspection is specified in tasks 
72-00-00-200-801 and 72-00-00-200-802 of the Boeing 777 Aircraft 
Maintenance Manual (AMM) Chapter 72.

Costs of Compliance

    There are about 208 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 53 airplanes of 
U.S. registry. The proposed actions would take about 1 work hour per 
airplane, at an average labor rate of $80 per work hour. Based on these 
figures, the estimated cost of the proposed AD for U.S. operators is 
$4,240, or $80 per airplane.

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 have 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 that the 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD and placed it in the AD docket. See the 
ADDRESSES section for a location to examine the regulatory evaluation.

[[Page 47756]]

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:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

    2. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2006-25609; Directorate Identifier 2005-NM-
263-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by October 
2, 2006.

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 
RB211 TRENT 800 engines.

Unsafe Condition

    (d) This AD results from reports of engine surges and internal 
engine damage due to ice accumulation during extended idle thrust 
operation in ground fog icing conditions. We are issuing this AD to 
prevent internal engine damage due to ice accumulation and shedding, 
which could cause a shutdown of both engines, and result in loss of 
control of the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Airplane Flight Manual (AFM) Revision

    (f) Within 14 days after the effective date of this AD, revise 
the Limitations Section of the Boeing Model 777 Airplane Flight 
Manual (AFM) to include the following statements. This may be done 
by inserting a copy of this AD in the AFM.

``GROUND OPERATIONS IN FREEZING FOG

    When freezing fog is reported and
    (a) the OAT is 0 degrees C to -6 degrees C then run up the 
engines to 50% N1 for 1 minute every 45 minutes taxi time, or
    (b) the OAT is -7 degrees C to -13 degrees C then run up the 
engines to 59% N1 for 1 minute for every 45 minutes taxi time, or
    (c) the OAT is colder than -13 degrees C and taxi time exceeds 
45 minutes, there is no run-up procedure.
    Regardless of temperature, if the core ice shedding procedure 
described above is not accomplished within 45 minutes total taxi 
time in freezing fog, but takeoff can be achieved within 60 minutes 
total taxi time in freezing fog, takeoff is permitted. A borescope 
inspection is required within 10 flights. If takeoff is not 
accomplished within 60 minutes total taxi time, then manually de-ice 
the engines.''
    (g) When a statement identical to that in paragraph (f) of this 
AD has been included in the general revisions of the AFM, the 
general revisions may be inserted into the AFM, and the copy of this 
AD may be removed from the AFM.

Inspection for Ice

    (h) If takeoff is not accomplished in freezing fog within 60 
minutes total taxi time, before further flight, perform an 
inspection for ice of the variable inlet guide vanes (VIGV's), in 
accordance with Task 12-33-03-200-801 of the Airplane Maintenance 
Manual (AMM); and inspect the low pressure compressor (fan) for ice 
after engine operation in freezing fog, in accordance with Task 12-
33-03-200-802 of Chapter 12-33-03, dated May 5, 2006, of the AMM.
    (1) If no ice is detected, the time already completed in 
freezing conditions can be reset to zero for subsequent operation.
    (2) If any ice is detected, before further flight, manually de-
ice the engine core inlet in accordance with Task 12-33-03-600-803, 
of Chapter 12-33-03 of the AMM, dated May 5, 2006, or manually de-
ice the engine by parking the aircraft in a heated hanger in 
accordance with Task 12-33-03-600-804 of Chapter 12-33-03 of the 
AMM, dated May 5, 2006.

Borescope Inspection for Damage

    (i) For airplanes on which the core ice shedding procedure is 
not accomplished within 45 minutes total taxi time, but that achieve 
takeoff within 60 minutes total taxi time in freezing fog, 
regardless of temperature during ground operations in freezing fog: 
Within 10 flight cycles after takeoff, perform a borescope 
inspection for damage of the compressor of both engines, in 
accordance with a method approved by the Manager, Seattle Aircraft 
Certification Office (ACO). One acceptable method of compliance is 
to perform the borescope inspection in accordance with Boeing Model 
777 Aircraft Maintenance Manual (AMM), Section 72, tasks 72-00-00-
200-801 and 72-00-00-200-802, both dated May 5, 2006. If any damage 
is detected, repair before further flight in accordance with the 
AMM.

Alternative Methods of Compliance (AMOCs)

    (j)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.
    (2) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.
    (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, and the approval must specifically refer to this 
AD.

    Issued in Renton, Washington, on August 8, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E6-13649 Filed 8-17-06; 8:45 am]
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