Document ID: FAA-2008-0402-0009
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Boeing Co. Model 747 and Model 767 Airplanes Equipped with General Electric Model CF6-80C2 or CF6-80A Series Engines
Posted Date: 2010-08-04T04:00Z

[Federal Register: August 4, 2010 (Volume 75, Number 149)]
[Proposed Rules]               
[Page 46868-46873]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr04au10-12]                         

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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.

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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 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.

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 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.

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