Federal Register / Vol. 73, No. 67 / Monday, April 7, 2008 / Proposed Rules 18721 

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; Boeing 

Model 747 Airplanes and Model 767 

Airplanes Equipped With General 

Electric CF6–80C2 and CF6–80A Series 

Engines 

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT). 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to adopt a 

new airworthiness directive (AD) for 

certain Boeing Model 747 airplanes and 

Model 767 airplanes. This proposed AD 

would require revising the airplane 

flight manual to advise the flightcrew to 

use certain procedures during descent 

in certain icing conditions. This 

proposed 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 

proposing 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 

without the ability of the engines to be 

relit, and consequent forced landing of 

the airplane. 

DATES: We must receive comments on 

this proposed AD by May 22, 2008. 

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. 

For service information identified in 

this AD, contact Boeing Commercial 

Airplanes, P.O. Box 3707, Seattle, 

Washington 98124–2207. 

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 have received reports indicating 

that there have been several in-flight 

engine flameout events, including one 

dual event, on Model 767 airplanes and 

four dual events on Model 747 

airplanes, in ice-crystal icing conditions 

at altitudes between 13,000 and 36,000 

feet during descent. These airplanes 

were equipped with General Electric 

(GE) CF6–80C2 series engines. Each 

flameout event was in or near 

convective weather with ice-crystal 

icing; this type of icing does not appear 

on radar due to its low reflectivity, and 

neither the airplane ice detector nor 

visual indications indicate the presence 

of icing conditions. Therefore, it is often 

undetected by the flightcrew. These 

conditions can cause ice crystals to 

accumulate in the core flow path of the 

engine during low-power conditions, 

such as idle or idle descent. The 

accumulated ice sheds during throttle 

increase and is ingested into the engine, 

causing the combustor to flameout 

resulting in an in-flight flameout and 

potential damage to the high pressure 

compressor due to ice impact. The GE 

CF6–80C2 and CF6–80A series engines 

models have similar compressor 

designs. 

Activating the engine anti-ice 

increases the flameout margin and 

reduces the potential for multiple 

engine flameouts by increasing bleed 

flow and idle speed. Engine anti-ice also 

assists with relighting the engines by 

turning on the igniters on airplanes that 

are not equipped with autorelight. 

However, in several of the subject 

engine flameout events, the engine antiice was already on when the engines 

flamed out. In each flameout event, the 

engines relit and continued to operate 

normally for the remainder of the flight. 

The requirement to activate the 

engine anti-ice prior to descent in 

visible moisture with total air 

temperature less than 10 °Celsius (C) 

and greater than ¥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 antiice when the airplane is in icing 

conditions. However, the primary inflight 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 ¥40 °C, and 

this proposed AD would require 

activation of engine anti-ice at 

temperatures below ¥40 °C. 

This condition, if not corrected, could 

result in a multiple engine flameout 

during flight without the ability of the 

engines to be relit, and consequent 

forced landing of the airplane. 

FAA’s Determination and Requirements 

of This Proposed AD 

We are proposing this AD because we 

evaluated all relevant information and 

determined the unsafe condition 

described previously is likely to exist or 

develop in other products of the(se) 

same type design(s). This proposed AD 

would require revising the airplane 

flight manual (AFM) to advise the 

flightcrew to use certain procedures 

during descent in certain icing 

conditions. 

Interim Action 

We consider this proposed AD 

interim action. If final action is later 


rfrederick on PROD1PC67 with PROPOSALS
18722 Federal Register / Vol. 73, No. 67 / Monday, April 7, 2008 / Proposed Rules 

identified, we might consider further 

rulemaking then. 

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

Action Work hours Average labor 

rate per hour Parts Cost per airplane 

Number of 

U.S.-registered 

airplanes 

Fleet cost 

AFM revision ............................................ 1 $80 $0 $80 340 $27,200 

Authority for this Rulemaking 

Title 49 of the United States Code 

specifies the FAA’s authority to issue 

rules on aviation safety. Subtitle I, 

Section 106, describes the authority of 

the FAA Administrator. Subtitle VII, 

Aviation Programs, describes in more 

detail the scope of the Agency’s 

authority. 

We are issuing this rulemaking under 

the authority described in Subtitle VII, 

Part A, Subpart III, Section 44701, 

‘‘General requirements.’’ Under that 

section, Congress charges the FAA with 

promoting safe flight of civil aircraft in 

air commerce by prescribing regulations 

for practices, methods, and procedures 

the Administrator finds necessary for 

safety in air commerce. This regulation 

is within the scope of that authority 

because it addresses an unsafe condition 

that is likely to exist or develop on 

products identified in this rulemaking 

action. 

Regulatory Findings 

We have determined that this 

proposed AD would not have federalism 

implications under Executive Order 

13132. This proposed AD would not 

have a substantial direct effect on the 

States, on the relationship between the 

national Government and the States, or 

on the distribution of power and 

responsibilities among the various 

levels of government. 

For the reasons discussed above, I 

certify that the proposed regulation: 

1. Is not a ‘‘significant regulatory 

action’’ under Executive Order 12866; 

2. Is not a ‘‘significant rule’’ under the 

DOT Regulatory Policies and Procedures 

(44 FR 11034, February 26, 1979); and 

3. Will not have a significant 

economic impact, positive or negative, 

on a substantial number of small entities 

under the criteria of the Regulatory 

Flexibility Act. 

We prepared a regulatory evaluation 

of the estimated costs to comply with 

this proposed AD and placed it in the 

AD docket. See the ADDRESSES section 

for a location to examine the regulatory 

evaluation. 

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 Federal Aviation 

Administration (FAA) amends § 39.13 

by adding the following new 

airworthiness directive (AD): 

Boeing: Docket No. FAA–2008–0402; 

Directorate Identifier 2007–NM–165–AD. 

Comments Due Date 

(a) The FAA must receive comments on 

this AD action by May 22, 2008. 

Affected ADs 

(b) None. 

Applicability 

(c) This AD applies to Boeing Model 747 

airplanes and Model 767 airplanes, certified 

in any category, equipped with General 

Electric CF6–80C2 or CF6–80A series 

engines. 

Unsafe Condition 

(d) 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 without the ability of the 

engines to be relit, and consequent forced 

landing of the airplane. 

Compliance 

(e) You are responsible for having the 

actions required by this AD performed within 

the compliance times specified, unless the 

actions have already been done. 

Airplane Flight Manual (AFM) Revision 

(f) Within 14 days after the effective date 

of this AD, revise the Limitations Section of 

the Boeing 747 or 767 AFM, as applicable, to 

include the following statement. This may be 

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.’’

Note 1: When a statement identical to that 

in paragraph (f) of this AD has been included 

in the general revisions of the AFM, the 

general revisions may be inserted into the 

AFM, and the copy of this AD may be 

removed from the AFM. 

Alternative Methods of Compliance 

(AMOCs) 

(g)(1) The Manager, Seattle Aircraft 

Certification Office, FAA, has the authority to 

approve AMOCs for this AD, if requested in 

accordance with the procedures found in 14 

CFR 39.19. 

(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 appropriate principal inspector 

(PI) in the FAA Flight Standards District 

Office (FSDO), or lacking a PI, your local 

FSDO. 

Issued in Renton, Washington, on March 

27, 2008. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. E8–7153 Filed 4–4–08; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2008–0406; Directorate 

Identifier 2007–NM–196–AD] 

RIN 2120–AA64 

Airworthiness Directives; Airbus Model 

A310 Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 


rfrederick on PROD1PC67 with PROPOSALS