Federal Aviation Administration (FAA), DOT.
Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.
We are revising an earlier proposed airworthiness directive (AD) for certain Model 747 airplanes and Model 767 airplanes. The original NPRM would have required revising the airplane flight manual (AFM) to advise the flightcrew to use certain procedures during descent in certain icing conditions. The original NPRM resulted from reports of several in-flight engine flameouts, including multiple dual engine flameout events and one total power loss event, in ice-crystal icing conditions. This action revises the original NPRM by revising the text of the proposed AFM revision. We are proposing this supplemental NPRM to ensure that the flightcrew has the proper procedures to follow in certain icing conditions. These certain icing conditions could cause a multiple engine flameout during flight with the potential inability to restart the engines, and consequent forced landing of the airplane.
We must receive comments on this supplemental NPRM by August 30, 2010.
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.
You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221.
Examining the AD Docket
You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed 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.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 98057-3356; telephone (425) 917-6500; fax (425) 917-6590.End Further Info End Preamble Start Supplemental Information
We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2008-0402; Directorate Identifier 2007-NM-165-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed 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 proposed AD.
We issued a notice of proposed rulemaking (NPRM) (the “original NPRM”) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain Model 747 airplanes and Model 767 airplanes. That original NPRM was published in the Federal Register on April 7, 2008 (73 FR 18721). That original NPRM proposed to require revising the airplane flight manual (AFM) to advise the flightcrew to use certain procedures during descent in certain icing conditions.
Actions Since Original NPRM Was Issued
Since we issued the original NPRM, we have received a report of another significant flameout event on a Model 747 airplane. As a result of this latest event, Boeing has revised the AFM instructions to include the activation of wing anti-ice for those altitudes where wing anti-ice can be used while still ensuring that other systems that use bleed air are adequately supplied with bleed air. Therefore, we have revised the AFM text specified in paragraph (g) of this supplemental NPRM to include this new text.
Other Relevant Rulemaking
Related NPRM, Docket FAA-2008-0403, Directorate Identifier 2007-NM-166-AD (73 FR 18719, April 7, 2008), proposed to require similar actions for Model MD-11 and MD-11F airplanes, certified in any category, equipped with General Electric (GE) CF6-80C2 series engines. These airplanes have been determined to be subject to the identified unsafe condition addressed in this supplemental NPRM.
Support for the Original NPRM
The Air Line Pilots Association, International supports the intent and language of the original NPRM. The National Transportation Safety Board (NTSB), based on the success of similar AFM requirements to address this unsafe condition on Hawker Beechcraft Corporation Model 400, 400A, and 400T series airplanes, and Model MU-300 airplanes, supports the adoption of the proposed requirements.Start Printed Page 46869
Request for FAA To Actively Pursue Research to Develop a Permanent Solution
The NTSB notes that the original NPRM is intended as interim action, and points out that it has issued Safety Recommendation A-06-59, dated August 25, 2006. In this safety recommendation the NTSB asked the FAA to “* * * work with engine and airplane manufacturers and other industry personnel as well as appropriate international authorities to actively pursue research to develop an ice detector that would alert pilots to internal engine icing and require that it be installed on new production turbojet engines, as well as retrofitted to existing turbojet engines.” Therefore, the NTSB hopes the FAA pursues research in concert with the multi-national Aircraft Icing Research Alliance that might develop an ice detector to alert flightcrews to the accretion of ice crystals on internal engine surfaces, so that flightcrews can take the appropriate actions.
We partially agree with the commenter's request. We agree that the GE CF6-80C2 series engine needs to be modified to mitigate the risk of flameouts caused by ice crystal accretion. However, at this time, we do not agree to pursue research to develop an ice detector that would alert flightcrews to the internal engine icing, or with requiring manufacturers to install ice detectors internal to the engines. In addition, no such designs have been proposed to the FAA. Instead, for future designs, we are developing rulemaking to show acceptable engine operation in an ice crystal environment. For engines that currently demonstrate a susceptibility to ice crystals, we are working with manufacturers to develop engine design changes to make engines more robust during ice crystal accumulation and shedding encounters. We will continue to provide feedback to the NTSB through the established process for addressing safety recommendations. For this AD, if different methods to address the unsafe condition are developed, under the provisions of paragraph (i) of this AD, we will consider requests for approval of an AMOC if sufficient data are submitted to substantiate that the method would provide an acceptable level of safety. No change to the supplemental NPRM is necessary in this regard.
Request to Require Demonstration of Non-Susceptibility in Future Designs
The NTSB states that it hopes the FAA will require future engine designs to demonstrate that they will not be susceptible to the accretion of ice crystals on internal surfaces. The NTSB points out that this request is in keeping with information provided to the NTSB by the FAA's icing expert during a briefing with the NTSB.
From these statements, we infer that the NTSB is requesting that we revise the original NPRM to include a statement of our intent to require manufacturers to demonstrate that future engine designs are not susceptible to the accretion of ice crystals. We partially agree. We agree that current FAA regulations addressing engine and airplane icing do not apply to the ice crystal environment; therefore, we are working with the aviation industry to develop appropriate regulations that address operation in an ice crystal environment. As we determine the necessary requirements to address this issue, we will consider additional rulemaking. We do not agree to revise this AD to include a statement regarding future regulations that have not yet been determined. No change to the supplemental NPRM is necessary in this regard.
Request to Withdraw the Original NPRM
GE acknowledges that a small number of inclement weather or significant weather system encounters have resulted in short-duration multiple engine power loss. GE points out that these few events occurred out of 14 million flights over 20 years of total service experience on the Model CF6-80C2 series engine. GE states that a forced landing resulting from one of these in-flight ice-crystal icing events is extremely improbable (including demonstrated relight performance). Therefore, GE asserts that the proposed condition does not meet the definition of “unsafe condition,” as defined by FAA Advisory Circular 39-8, “Continued Airworthiness Assessments of Powerplant and Auxiliary Power Unit Installations of Transport Category Airplanes,” dated September 8, 2003.
From these statements, we infer that GE requests that we withdraw the original NPRM. We do not agree. We have evaluated the unsafe condition and find that sufficient data exist to demonstrate that the environment that causes the engine flameout would likely cause engine damage that potentially would prevent an engine from relighting. The condition could exist on all of an airplane's engines, resulting in a forced landing. The advisory circular referenced by the commenter merely provides guidance. We have determined that an unsafe condition exists, and the appropriate vehicle for correcting an unsafe condition is an AD. We have not changed the supplemental NPRM regarding this issue.
Request to Delay Issuance of AD Until New Software Modification Is Implemented
Lufthansa Technik (Lufthansa) suggests that the AD be postponed until a new electronic control unit (ECU) software modification has been implemented, and GE can present data to operators to show the need to mandate the proposed procedures. Lufthansa asserts that GE did not provide data to the airlines on how many flameout events have occurred. Consequently, Lufthansa states that its flightcrews have not used the procedure specified in the original NPRM. Lufthansa points out that it is usually common sense to use the proposed procedure; therefore, it is hard to understand why the proposed procedure will now be mandatory.
We do not agree to delay issuance of this action. We do not consider that delaying this action until after the release of a possible software revision is warranted. As Lufthansa points out, while the proposed procedure might be common sense to some, most flightcrews are not using the proposed procedure; therefore, as stated previously, we have found that ECU software logic alone does not provide an acceptable level of safety. We have determined that the in-flight anti-ice activation procedures in combination with the electronic engine control (EEC) software are necessary to mitigate the unsafe condition. However, under the provisions of paragraph (i) of the supplemental NPRM, we will consider requests for approval of an AMOC if sufficient data are submitted to substantiate that the change would provide an acceptable level of safety. We find that delaying this action would be inappropriate in light of the identified unsafe condition, and have made no change to this supplemental NPRM in this regard.
Request to Revise Related AD To Reduce Compliance Time
Global Supply Systems (Global) requests that we revise AD 2007-12-07, Amendment 39-15085 (72 FR 31174, June 6, 2007), to require a much earlier compliance time for the software update required by that AD. That AD applies to GE Model CF6-80C2B series turbofan engines with ECUs installed on Model 747 and 767 airplanes. Global explains that GE has two engine software revisions to the EEC bleed scheduling, which, while not preventing flameouts Start Printed Page 46870from occurring, do appear to mitigate the effect. Global notes that the later software revision is subject to AD 2007-12-07, which requires compliance by July 10, 2012. Global reasons that software upgrades are required only on workshop visits for unserviceability or engine change, and with current serviceability levels, the mandatory upgrading of current equipment is extremely slow, leading to substantial levels of unmodified software installed on airplanes. Global asserts that, while this problem increases pressure to introduce procedures to alleviate the problem, it does not adequately address the improvement in safety that would be incumbent on bringing the compliance date of AD 2007-12-07 forward to require use of a programmed upgrade of the EEC software.
We do not agree to change the compliance time for the actions required by AD 2007-12-07. In developing an appropriate compliance time for the requirements of that AD, we considered the safety implications, parts availability, and normal maintenance schedules for timely accomplishment of the requirements of that AD. In consideration of all of these factors, we determined that the compliance time required by that AD represents an appropriate interval in which the software can be updated in a timely manner within the fleet, while still maintaining an adequate level of safety. However, operators are always permitted to accomplish the requirements of an AD at a time earlier than the specified compliance time; therefore, an operator may choose to update the software, as required by that AD, before the required compliance date specified in that AD. If additional data are presented that would justify a shorter compliance time, we might consider further rulemaking on this issue. We have made no change to this supplemental NPRM in this regard.
Request to Remove GE Model CF6-80A Series Engines
GE Aviation (GE) suggests removing all references to GE Model CF6-80A series engines from the original NPRM. GE states that it is not aware of any confirmed engine flameout events related to GE Model CF6-80A series engines due to ice-crystal icing conditions. GE explains that this might be due to several factors:
- A significantly different type-design booster from that of the GE Model CF6-80C2 series engines (GE Model CF6-80A series engines have fewer rotor and booster stages, with 30 percent fewer airfoils, resulting in significantly reduced potential accretion sites than the GE Model CF6-80C2 series engines);
- A significantly different variable bleed valve system (especially the exit path); and
- A purely hydro-mechanical (power management control with mechanical engine control) fuel control system, where as GE Model CF6-80C2 series engines have predominantly FADEC control with different fueling schedules and response characteristics.
From these statements, we infer that GE is requesting that we remove airplanes equipped with GE Model CF6-80A series engines from the applicability of this supplemental NPRM. We do not agree. Although there have been no recorded flameout events related to GE Model CF6-80A series engines, flightcrews are not required to determine which model of engine is installed on the airplane. Therefore, it is possible that the flightcrew would not perform the necessary AFM procedure because the flightcrew is unaware of the engine model that is installed on the airplane they are flying. However, under the provisions of paragraph (i) of this supplemental NPRM, we will consider requests for approval of an AMOC for airplanes equipped with GE Model CF6-80A series airplanes if sufficient data are submitted to substantiate an acceptable level of safety. We have made no change to this supplemental NPRM in this regard.
Request to Acknowledge No Flameout Events on GE Model CF6-80A Series Engines
Boeing states that the FAA should revise the Discussion section of the original NPRM to acknowledge that there have been no flameout events recorded on GE Model CF6-80A series engines. While this engine has a similar compressor design, Boeing believes it has certain design features (including the VBV door geometry and schedule), which might explain why it does not have flameout events. Boeing asserts that operators of airplanes equipped with GE Model CF6-80A series engines might desire to ask for an AMOC with this AD for those airplanes.
We partially agree. We agree that there have been no recorded flameout events to date on GE Model CF6-80A series engines during ice-crystal icing conditions. However, as previously noted, the Discussion section in the original NPRM is not restated in this supplemental NPRM; therefore, there is no need to revise the supplemental NPRM in this regard.
Request to Revise Wording in the Discussion Section of the Original NPRM
GE suggests that we revise the wording of the Discussion section of the original NPRM to remove the word “core,” or, if that is not acceptable, to change “core flow path” to “booster and core flow path.” GE points out that the term “core” can be interpreted to mean just the high-pressure spool portion of a turbofan.
We partially agree. We do not agree with GE's suggestion to remove the word “core” from the Discussion section. We do agree that the phrase “booster and core flow path” is more accurate; however, because the Discussion section of the original NPRM is not restated in this supplemental NPRM, there is no need to revise the supplemental NPRM in this regard.
GE also suggests that we revise the Discussion section of the NPRM to remove the following sentence: “The GE CF6-80C2 and CF6-80A series engines models have similar compressor designs.” GE suggests removing this sentence for the same reasons it requests that we remove GE Model CF6-80A series engines from the applicability of the original NPRM. Or, if we do not agree to remove that sentence, GE proposes that we revise that sentence to clarify the statement of similarity of compressor designs of the GE Model CF6-80A and CF6-80C2 series engines. GE proposes changing the sentence to read, “The GE CF6-80C2 and CF6-80A series engines models have different booster and VBV system designs, but similar compressor designs.”
We partially agree. We do not agree with GE's suggestion to remove the subject sentence from the Discussion section. We do agree that the revised wording suggested by GE is more accurate; however, as previously noted, the Discussion section in the original NPRM is not restated in this supplemental NPRM, therefore, there is no need to revise the supplemental NPRM in this regard.
GE also believes that, in the Discussion section of the original NPRM, the reference to “−40 °C” in the explanation of conditions for activating engine anti-ice on airplanes equipped with a primary in-flight ice detection system should be changed to “SAT −40 °C.”
From this statement, we infer that GE is requesting that we revise the Discussion section of the original NPRM to clarify the referenced temperature. We partially agree. We agree that the temperature should be “SAT −40 °C.” However, as previously noted, the Start Printed Page 46871Discussion section in the original NPRM is not restated in this supplemental NPRM, there is no need to revise the supplemental NPRM in this regard.
Request to Revise the Costs of Compliance Section of the NPRM
GE suggests that there should be an operational cost of compliance included in the proposed Costs of Compliance provided in the original NPRM. GE states that, while increasing engine off-take or bleed does provide additional margin against flameout, doing so requires somewhat increased fuel burn. GE believes the proposed procedure would be required on a significant percentage of flights, and estimates that the incremental fuel required is around 100 pounds of fuel per flight for Model 747 airplanes, but less for Model 767 airplanes.
We do not agree to include an operational cost. The cost information in AD actions describes only the direct costs of the specific actions required by the AD: an AFM revision in this case. The estimated cost of this action represents the time necessary to perform only the actions actually required by this supplemental NPRM. We recognize that, in doing the actions required by an AD, operators might incur operational costs in addition to the direct costs. The cost analysis in AD rulemaking actions, however, typically does not include incidental or operational costs such as the time required for planning or other administrative actions, and, in this case, possible additional fuel costs. Those costs, which might vary significantly among operators, are almost impossible to calculate. Additionally, we have determined that the additional fuel burn necessitated by the AFM procedure would be insignificant. We have not changed the supplemental NPRM in this regard.
Request to Remove Nacelle Anti-Ice Requirement in Certain Icing Conditions
Global requests that we revise the original NPRM to remove the proposed requirement to select manual nacelle anti-ice in visible moisture below a total air temperature (TAT) of 10 °Celsius (C) during descent at lower altitudes (e.g., Flight Level (FL) 100). Global states that its primary area of operation includes a high proportion of flights in regions that have been particularly affected by ice crystal accretion incidents, so it is concerned about the risks involved with the identified unsafe condition. However, although Global understands and supports measures to reduce the risks associated with ice-crystal icing, it considers forcing use of manual nacelle anti-ice during descent in visible moisture to be too prescriptive and deleterious to safety.
First, Global points out that the proposed procedure is required irrespective of altitude, and that nacelle anti-ice will frequently be unnecessarily required to be selected “ON,” particularly at lower altitudes where ice crystal ingestion and subsequent flameout have not been experienced.
Second, Global explains that its flightcrews have become accustomed to using automatic ice detection and are therefore less familiar with the detection of conditions requiring the manual selection of nacelle anti-ice. For this reason, Global asserts that there will be an increase in the flightcrew's workload during descent as the external ambient conditions are assessed more frequently, especially at lower altitudes where air traffic control and approach procedures generate a higher workload.
Third, Global states that increase in idle thrust level dependant on engine anti-ice increases the required descent distance. Global declares that the use of the flight management computer's (FMC's) descent predictions is essential for environmental and economic reasons to minimize fuel usage. Because descent is predicated on not using the nacelle anti-ice, requiring use of the nacelle anti-ice will negate this prediction. Although the FMC can be programmed to account for the effect of using nacelle anti-ice below an entered altitude, this method is not efficient and would either cause the airplane to become high and fast because of inadequate distance for descent, or, conversely, cause the airplane to descend too early, increasing fuel usage and noise disturbance.
Fourth, Global states that it is aware of a similar process requiring manual activation of nacelle anti-ice on a different airplane/engine combination, which also suffers from ice crystal accretion. Global points out that process allows reversion to auto nacelle anti-ice below 10,000 feet.
We do not agree to remove the proposed requirement to select manual nacelle anti-ice in visible moisture below a TAT of 10 °C during descent at lower altitudes (e.g., 10,000 feet). Contrary to Global's assertion that flameout caused by ice-crystal icing has not been experienced at lower altitudes, flameouts at altitudes lower than 10,000 feet have occurred as a result of ice-crystal icing.
We recognize that the descent phase of flight requires a higher level of workload for the flightcrew; however, icing can occur at any altitude at any time, and is most common in descents as the airplane passes through visible moisture. As we explained in the original NPRM, ice-crystal icing does not appear on radar due to its low reflectivity, and the airplane ice detector does not detect the presence of these specific icing conditions. Therefore, ice-crystal icing is often undetected by the flightcrew. Although these specific icing conditions are difficult to detect, all pilots should know what visible moisture is and how to recognize it without significant impact to flightcrew workload. In fact, all pilots need be cognizant of the conditions they are flying in and be capable of reacting to those conditions, regardless of the phase of flight.
The requirement to activate the engine anti-ice prior to descent in visible moisture with TAT less than 10 °C and greater than saturated air temperature (SAT) −40 °C already exists for airplanes that are not equipped with a primary in-flight ice detection system, which is designed to automatically activate wing anti-ice and engine anti-ice when the airplane is in icing conditions. However, the primary in-flight ice detection system does not detect ice-crystal icing; therefore, the engine anti-ice would not be activated during these icing encounters. There is no requirement to activate engine anti-ice at temperatures below SAT −40 °C, and this proposed AD would require activation of engine anti-ice at temperatures below SAT −40 °C. Activating the engine anti-ice increases the flameout margin and reduces the potential for multiple engine flameouts by increasing bleed flow and idle speed. As far as Global's assertion that use of manual nacelle anti-ice will increase fuel usage, we have confirmed that any increase in fuel usage caused by use of manual nacelle anti-ice would be insignificant. Engine anti-ice also assists with relighting the engines by turning on the igniters on airplanes that are not equipped with autorelight. We have determined that FMC software logic alone does not provide an adequate level of safety in lieu of manual anti-ice activation in ice-crystal icing conditions.
For the reasons discussed previously, we have concluded that requiring selection of manual nacelle anti-ice in visible moisture below a TAT of 10 °C during descent at lower altitudes does increase safety and does not impose undue burdens on operators. We have made no change to the supplemental NPRM in this regard.Start Printed Page 46872
FAA's Determination and Proposed Requirements of the Supplemental NPRM
We are proposing this supplemental NPRM because we evaluated all pertinent information and determined an unsafe condition exists and is likely to exist or develop on other products of these same type designs. Certain changes described above expand the scope of the original NPRM. As a result, we have determined that it is necessary to reopen the comment period to provide additional opportunity for the public to comment on this supplemental NPRM.
We consider this proposed AD interim action. If final action is later identified, we might consider further rulemaking then.
Explanation of Additional Paragraph in the Supplemental NPRM
We have added a new paragraph (d) to this supplemental NPRM to provide the Air Transport Association (ATA) of America subject code 30: Ice and rain protection. This code is added to make this supplemental NPRM parallel with other new AD actions. We have reidentified subsequent paragraphs accordingly.
Explanation of Change Made to the Supplemental NPRM
We have revised this supplemental NPRM to identify the legal name of the manufacturer as published in the most recent type certificate data sheet for the affected airplane models.
Explanation of Change to Costs of Compliance
Since issuance of the original NPRM, we have increased the labor rate used in the Costs of Compliance from $80 per work-hour to $85 per work-hour. The Costs of Compliance information, below, reflects this increase in the specified hourly labor rate.
Costs of Compliance
There are about 1,064 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.
|Action||Work hours||Average labor rate per hour||Parts||Cost per airplane||Number of U.S.-registered airplanes||Fleet cost|
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 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 this 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.
You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.Start List of Subjects
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 FAA amends § 39.13 by adding the following new AD:
The Boeing Company: Docket No. FAA-2008-0402; Directorate Identifier 2007-NM-165-AD.
Comments Due Date
(a) We must receive comments by August 30, 2010.
(c) This AD applies to The Boeing Company Model 747 airplanes and Model 767 airplanes, certified in any category, equipped with General Electric Model CF6-80C2 or CF6-80A series engines.
(d) Air Transport Association (ATA) of America Code 30: Ice and rain protection.
(e) This AD results from reports of several in-flight engine flameouts, including multiple dual engine flameout events and one total power loss event, in ice-crystal icing conditions. We are issuing this AD to ensure that the flightcrew has the proper procedures to follow in certain icing conditions. These certain icing conditions could cause a multiple engine flameout during flight with the potential inability to restart the engines, and consequent forced landing of the airplane.
(f) 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
(g) Within 14 days after the effective date of this AD, revise the Limitations Section of the Boeing 747 or 767 AFM, as applicable, to include the following statement. This may be Start Printed Page 46873done by inserting a copy of this AD into the AFM.
“Prior to descent in visible moisture and TAT less than 10 °C, including SAT less than −40 °C, nacelle anti-ice switch must be in the ON position. At or below 22,000 ft, wing anti-ice selector must be in the ON position.”
When a statement identical to that in paragraph (g) 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.
Special Flight Permits
(h) 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), may be issued to operate the airplane to a location where the requirements of this AD can be accomplished provided the operational requirements defined in the Limitations Section of the AFM are used if icing is encountered.
Alternative Methods of Compliance (AMOCs)
(i)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to Attn: 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. Information may be e-mailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
(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 principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.
Issued in Renton, Washington, on July 27, 2010.
Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 2010-19154 Filed 8-3-10; 8:45 am]
BILLING CODE 4910-13-P