Federal Aviation Administration (FAA), Department of Transportation (DOT).
Notice of proposed rulemaking (NPRM).
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.
We must receive comments on this proposed AD by October 2, 2006.
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, Start Printed Page 47755Washington 98124-2207, for the service information identified in this proposed AD.Start Further Info
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.End Further Info End Preamble Start Supplemental Information
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.
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.
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.Start List of Subjects Start Printed Page 47756
List of Subjects in 14 CFR Part 39End List of Subjects
The Proposed Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:Start Part
PART 39—AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
2. The Federal Aviation Administration (FAA) amends § 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.
(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.
(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.
(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 § 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.
Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. E6-13649 Filed 8-17-06; 8:45 am]
BILLING CODE 4910-13-P