Airworthiness Directives; The Boeing Company Model 747 Airplanes and Model 767 Airplanes Equipped With General Electric Model CF6-80C2 or CF6-80A Series Engines, 46868-46873 [2010-19154]

Download as PDF 46868 Federal Register / Vol. 75, No. 149 / Wednesday, August 4, 2010 / Proposed Rules Management and Budget (OMB) has approved the information collection requirements and has assigned OMB Control Number 2120–0056. Related Information (m) Refer to MCAI EASA Airworthiness Directive 2006–0198, dated July 11, 2006; Shorts Service Bulletins SD330–28–37, SD360–28–23, SD360 SHERPA–28–3, and SD3 SHERPA–28–2, all dated June 2004; and the service information listed in Tables 1, 2, and 3 of this AD; for related information. Issued in Renton, Washington, on July 26, 2010. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 2010–19172 Filed 8–3–10; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2008–0402; Directorate Identifier 2007–NM–165–AD] RIN 2120–AA64 Airworthiness Directives; The Boeing Company Model 747 Airplanes and Model 767 Airplanes Equipped With General Electric Model CF6–80C2 or CF6–80A Series Engines Federal Aviation Administration (FAA), DOT. ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of comment period. AGENCY: 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. jdjones on DSK8KYBLC1PROD with PROPOSALS-1 SUMMARY: VerDate Mar<15>2010 13:18 Aug 03, 2010 Jkt 220001 We must receive comments on this supplemental NPRM by August 30, 2010. ADDRESSES: You may send comments by any of the following methods: • Federal eRulemaking Portal: Go to https://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. DATES: Examining the AD Docket You may examine the AD docket on the Internet at https:// 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. 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: Comments Invited 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. PO 00000 Frm 00010 Fmt 4702 Sfmt 4702 We will post all comments we receive, without change, to https:// 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. Discussion 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. E:\FR\FM\04AUP1.SGM 04AUP1 Federal Register / Vol. 75, No. 149 / Wednesday, August 4, 2010 / Proposed Rules jdjones on DSK8KYBLC1PROD with PROPOSALS-1 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 VerDate Mar<15>2010 13:18 Aug 03, 2010 Jkt 220001 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 PO 00000 Frm 00011 Fmt 4702 Sfmt 4702 46869 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 E:\FR\FM\04AUP1.SGM 04AUP1 46870 Federal Register / Vol. 75, No. 149 / Wednesday, August 4, 2010 / Proposed Rules from 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. jdjones on DSK8KYBLC1PROD with PROPOSALS-1 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 VerDate Mar<15>2010 13:18 Aug 03, 2010 Jkt 220001 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. PO 00000 Frm 00012 Fmt 4702 Sfmt 4702 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 E:\FR\FM\04AUP1.SGM 04AUP1 Federal Register / Vol. 75, No. 149 / Wednesday, August 4, 2010 / Proposed Rules Discussion section in the original NPRM is not restated in this supplemental NPRM, there is no need to revise the supplemental NPRM in this regard. jdjones on DSK8KYBLC1PROD with PROPOSALS-1 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 offtake 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 VerDate Mar<15>2010 13:18 Aug 03, 2010 Jkt 220001 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 icecrystal 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 PO 00000 Frm 00013 Fmt 4702 Sfmt 4702 46871 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, icecrystal 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 antiice 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. E:\FR\FM\04AUP1.SGM 04AUP1 46872 Federal Register / Vol. 75, No. 149 / Wednesday, August 4, 2010 / Proposed Rules 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. identified, we might consider further rulemaking then. recent type certificate data sheet for the affected airplane models. Explanation of Additional Paragraph in the Supplemental NPRM Explanation of Change to Costs of Compliance 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. 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. Explanation of Change Made to the Supplemental NPRM Interim Action We consider this proposed AD interim action. If final action is later We have revised this supplemental NPRM to identify the legal name of the manufacturer as published in the most 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. Costs of Compliance ESTIMATED COSTS Action Work hours Average labor rate per hour Parts Cost per airplane Number of U.S.-registered airplanes Fleet cost AFM revision ............................................ 1 $85 $0 $85 340 $28,900 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. jdjones on DSK8KYBLC1PROD with PROPOSALS-1 Regulatory Findings 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: VerDate Mar<15>2010 13:18 Aug 03, 2010 Jkt 220001 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. 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. § 39.13 [Amended] 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. PO 00000 Frm 00014 Fmt 4702 Sfmt 4702 Comments Due Date (a) We must receive comments by August 30, 2010. Affected ADs (b) None. Applicability (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. Subject (d) Air Transport Association (ATA) of America Code 30: Ice and rain protection. Unsafe Condition (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. Compliance (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 E:\FR\FM\04AUP1.SGM 04AUP1 Federal Register / Vol. 75, No. 149 / Wednesday, August 4, 2010 / Proposed Rules done 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.’’ Note 1: 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. DEPARTMENT OF TRANSPORTATION Special Flight Permits AGENCY: (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: 9ANM-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. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 2010–19154 Filed 8–3–10; 8:45 am] jdjones on DSK8KYBLC1PROD with PROPOSALS-1 BILLING CODE 4910–13–P VerDate Mar<15>2010 13:18 Aug 03, 2010 Jkt 220001 Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2008–0670; Directorate Identifier 2007–NM–339–AD] RIN 2120–AA64 Airworthiness Directives; Airbus Model A318–111 and A318–112 Airplanes and Model A319, A320, and A321 Series Airplanes Federal Aviation Administration (FAA), DOT. ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of comment period. We are revising an earlier NPRM for the products listed above. This action revises the earlier NPRM by expanding the scope. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: SUMMARY: Damage to the lower lateral fittings of the 80VU rack, typically elongated holes, migrated bushes [bushings], and/or missing bolts have been reported in-service. In addition damage to the lower central support fitting (including cracking) has been reported. In the worst case scenario a complete failure of the 80VU fittings in combination with a high load factor or strong vibration could lead to failure of the rack structure and/or computers or rupture/disconnection of the cable harnesses to one or more computers located in the 80VU. This rack contains computers for Flight Controls, Communication and Radio-navigation. These functions are duplicated across other racks but during critical phases of flight the multiple system failures/re-configuration may constitute an unsafe condition. * * * * * The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI. DATES: We must receive comments on this proposed AD by August 30, 2010. ADDRESSES: You may send comments by any of the following methods: • Federal eRulemaking Portal: Go to https://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– PO 00000 Frm 00015 Fmt 4702 Sfmt 4702 46873 30, West Building Ground Floor, Room W12–40, 1200 New Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. For service information identified in this proposed AD, contact Airbus, Airworthiness Office—EAS, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 44 51; e-mail: account.airworth-eas@airbus.com; Internet https://www.airbus.com. 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 https:// www.regulations.gov; or in person at the Docket Operations office 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 Operations office (telephone (800) 647–5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt. Tim Dulin, Aerospace Engineer, International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057–3356; telephone (425) 227–2141; fax (425) 227–1149. FOR FURTHER INFORMATION CONTACT: SUPPLEMENTARY INFORMATION: Comments Invited 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–2008–0670; Directorate Identifier 2007–NM–339–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 based on those comments. We will post all comments we receive, without change, to https:// 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. E:\FR\FM\04AUP1.SGM 04AUP1

Agencies

[Federal Register Volume 75, Number 149 (Wednesday, August 4, 2010)]
[Proposed Rules]
[Pages 46868-46873]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-19154]

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0402; Directorate Identifier 2007-NM-165-AD]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Model 747 Airplanes
and Model 767 Airplanes Equipped With General Electric Model CF6-80C2
or CF6-80A Series Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of
comment period.

-----------------------------------------------------------------------

SUMMARY: 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.

DATES: We must receive comments on this supplemental NPRM by August 30,
2010.

ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Portal: Go to https://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 https://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.

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:

Comments Invited

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 https://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.

Discussion

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.

[[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

[[Page 46870]]

from 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 [deg]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 [deg]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 [deg]C.'' However, as previously noted, the

[[Page 46871]]

Discussion 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 [deg]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 [deg]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 [deg]C and greater than
saturated air temperature (SAT) -40 [deg]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 [deg]C, and this proposed AD would
require activation of engine anti-ice at temperatures below SAT -40
[deg]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 [deg]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.

[[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.

Interim Action

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.

Estimated Costs
--------------------------------------------------------------------------------------------------------------------------------------------------------
Number of U.S.-
Action Work hours Average labor Parts Cost per registered Fleet cost
rate per hour airplane airplanes
--------------------------------------------------------------------------------------------------------------------------------------------------------
AFM revision...................................... 1 $85 $0 $85 340 $28,900
--------------------------------------------------------------------------------------------------------------------------------------------------------

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 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.

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 FAA amends Sec. 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.

Affected ADs

(b) None.

Applicability

(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.

Subject

(d) Air Transport Association (ATA) of America Code 30: Ice and
rain protection.

Unsafe Condition

(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.

Compliance

(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

[[Page 46873]]

done by inserting a copy of this AD into the AFM.

``Prior to descent in visible moisture and TAT less than 10
[deg]C, including SAT less than -40 [deg]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.''

Note 1: 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.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2010-19154 Filed 8-3-10; 8:45 am]
BILLING CODE 4910-13-P

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