Federal Register / Vol. 63, No. 87 /Wednesday, May 6, 1998 /Rules and Regulations 24913

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–ANE–28–AD; Amendment

39–10496; AD 98–09–15]

RIN 2120–AA64

Airworthiness Directives; General

Electric Company Model GE90–76B

Turbofan Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment adopts a

new airworthiness directive (AD),

applicable to General Electric Company

(GE) Model GE90–76B turbofan engines,

that requires reduced life limits for

certain rotating components. This

amendment is prompted by the results

of a refined life analysis performed by

the manufacturer which revealed

minimum calculated low cycle fatigue

lives lower than the published low cycle

fatigue retirement lives for certain

rotating components. The actions

specified by this AD are intended to

prevent a low cycle fatigue failure of a

rotating component and possibly an

uncontained engine failure.

DATES: Effective July 6, 1998.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of July 6, 1998.

ADDRESSES: The service information

referenced in this AD may be obtained

from General Electric Company

Technical Services, Attention: Leader

for distribution/microfilm, 10525

Chester Road, Cincinnati, OH 45215,

telephone (513) 672–8400 Ext. 114, Fax

(513) 672–8422. This information may

be examined at the FAA, New England

Region, Office of the Regional Counsel,

12 New England Executive Park,

Burlington, MA; or at the Office of the

Federal Register, 800 North Capitol

Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Karen Curtis, Aerospace Engineer,

Engine Certification Office, FAA, Engine

and Propeller Directorate, 12 New

England Executive Park, Burlington, MA

01803–5299; telephone (781) 238–7192,

fax (781) 238–7199.

SUPPLEMENTARY INFORMATION: A

proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) to

include an airworthiness directive (AD)

that is applicable to General Electric

Company (GE) Model GE90–76B

turbofan engines was published in the

Federal Register on September 24, 1997

(62 FR 49179). That action proposed to

require reduced life limits for certain

rotating components.

Interested persons have been afforded

an opportunity to participate in the

making of this amendment. Due

consideration has been given to the

comment received.

One commenter supports the rule as

proposed.

Since publication of the Notice of

Proposed Rulemaking (NPRM), GE has

provided the FAA with additional

analysis that substantiates the original

cyclic life for the stage 7 disks (part

numbers 350–000–656–0 and 350–000–

657–0) of 10,000 cycles. These disks are

exempted from this AD based on recent

FAA approval of GE’s refined life

analysis substantiating the original

cyclic life of 10,000 cycles for this

engine model. The latest revision of the

GE90 Engine Manual, Chapter 05–11–

00, Life Limits 001, restored the stage 7

disk lives for the model to 10,000

cycles.

After careful review of the available

data, including the comment noted

above, the FAA has determined that air

safety and the public interest require the

adoption of the rule with the changes

described previously. The FAA has

determined that these changes will

neither increase the economic burden

on any operator nor increase the scope

of the AD.

There are approximately 24 engines of

the affected design in the worldwide

fleet. The manufacturer has advised the

FAA that there are currently no engines

installed on aircraft of U.S. registry that

would be affected by this AD. Therefore,

there is no associated cost impact on

U.S. operators as a result of this AD.

The FAA estimates that the most

representative engines will have 3 of the

6 life-limited-reduced components

installed. Assuming the 3 components

are the High Pressure Compressor Rotor

(HPCR) 2–6 spool, HPCR CDP seal, and

the Low Pressure Turbine cone shaft

and that the parts cost is proportional to

the reduction of the low cycle fatigue

retirement lives, the required parts will

cost approximately $181,993 per engine.

Based on these figures, the FAA

estimates that if an engine were

imported to the U.S., the total cost

impact of this AD would be $181,993

per engine.

The regulations adopted herein will

not have substantial direct effects 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. Therefore, in

accordance with Executive Order 12612,

it is determined that this final rule does

not have sufficient federalism

implications to warrant the preparation

of a Federalism Assessment.

For the reasons discussed above, I

certify that this action (1) is not a

‘‘significant regulatory action’’ under

Executive Order 12866; (2) is not a

‘‘significant rule’’ under 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. A final evaluation has

been prepared for this action and it is

contained in the Rules Docket. A copy

of it may be obtained from the Rules

Docket at the location provided under

the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation

safety, Incorporation by reference,

Safety.

Adoption of the Amendment

Accordingly, pursuant to the

authority delegated to me by the

Administrator, the Federal Aviation

Administration amends part 39 of the

Federal Aviation Regulations (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. Section 39.13 is amended by

adding the following new airworthiness

directive:

98–09–15 General Electric Company:

Amendment 39–10496. Docket No. 97–

ANE–28–AD.

Applicability: General Electric Company

(GE) GE90–76B Model turbofan engines,

installed on but not limited to Boeing 777

series aircraft.

Note 1: This airworthiness directive (AD)

applies to each engine identified in the

preceding applicability provision, regardless

of whether it has been modified, altered, or

repaired in the area subject to the

requirements of this AD. For engines that

have been modified, altered, or repaired so

that the performance of the requirements of

this AD is affected, the owner/operator must

request approval for an alternative method of

compliance in accordance with paragraph (d)

of this AD. The request should include an

assessment of the effect of the modification,

alteration, or repair on the unsafe condition

addressed by this AD; and, if the unsafe

condition has not been eliminated, the

request should include specific proposed

actions to address it.
24914 Federal Register / Vol. 63, No. 87 /Wednesday, May 6, 1998 /Rules and Regulations

Compliance: Required as indicated, unless

accomplished previously.

To prevent a low cycle fatigue failure of a

rotating component and possibly an

uncontained engine failure, accomplish the

following:

(a) Remove from service those components

listed in Table 1 of GE90 Alert Service

Bulletin (ASB) No. 72–A318, dated June 27,

1997, (except as noted in paragraph (b) of this

AD) and replace with a serviceable

component, prior to exceeding the new cyclic

life limits established in paragraph 1.D. (1) of

GE90 ASB No. 72–A318, dated June 27, 1997.

(b) GE has provided the FAA with

additional analysis that substantiates the

original cycle life for the stage 7 disks (part

numbers 350–000–656–0 and 350–000–657–

0) of 10,000 cycles. These disks are exempted

from this AD based on recent FAA approval

of GE’s refined life analysis substantiating the

original cycle life of 10,000 cycles for this

engine model.

Note 2: The revised component life limits

noted in GE90 ASB No. 72–A318, dated June

27, 1997, were added to the GE90 Engine

Manual Chapter 05–11–00, Life Limits 001,

in the August 1, 1997, revision. The latest

revision of the GE90 Engine Manual, Chapter

05–11–00, Life Limits 001, restored the stage

7 disk lives for the model to 10,000 cycles.

(c) Except as provided in paragraph (d) of

this AD, no replacement times may be

approved for these parts.

(d) An alternative method of compliance or

adjustment of the compliance time that

provides an acceptable level of safety may be

used if approved by the Manager, Engine

Certification Office. Operators shall submit

their requests through an appropriate FAA

Principal Maintenance Inspector, who may

add comments and then send it to the

Manager, Engine Certification Office.

Note 3: Information concerning the

existence of approved alternative methods of

compliance with this airworthiness directive,

if any, may be obtained from the Engine

Certification Office.

(e) Special flight permits may be issued in

accordance with sections 21.197 and 21.199

of the Federal Aviation Regulations (14 CFR

21.197 and 21.199) to operate the aircraft to

a location where the requirements of this AD

can be accomplished.

(f) The actions required by this AD shall be

done in accordance with the following GE90

ASB:

Document No. Pages Date

72–A318 ............... 1–5 June 27, 1997.

Total Pages: 5.

This incorporation by reference was

approved by the Director of the Federal

Register in accordance with 5 U.S.C. 552(a)

and 1 CFR part 51. Copies may be obtained

from General Electric Company Technical

Services, Attention: Leader for distribution/

microfilm, 10525 Chester Road, Cincinnati,

OH 45215, telephone (513) 672–8400 Ext.

114, Fax (513) 672–8422. Copies may be

inspected at the FAA, New England Region,

Office of the Regional Counsel, 12 New

England Executive Park, Burlington, MA; or

at the Office of the Federal Register, 800

North Capitol Street NW., suite 700,

Washington, DC.

(g) This amendment becomes effective on

July 6, 1998.

Issued in Burlington, Massachusetts, on

April 20, 1998.

Jay J. Pardee,

Manager, Engine and Propeller Directorate,

Aircraft Certification Service.

[FR Doc. 98–11440 Filed 5–5–98; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–NM–138–AD; Amendment

39–10510; AD 98–09–29]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 747–400 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment adopts a

new airworthiness directive (AD),

applicable to certain Boeing Model 747–

400 series airplanes, that requires

removal and reconfiguration of the

battery grounds of the auxiliary power

unit (APU). This amendment is

prompted by reports of smoke or fire

coming from the APU due to battery

grounds that were not installed or

maintained properly. The actions

specified by this AD are intended to

prevent overheating and heat damage of

the APU battery grounds due to

improper installation of the APU battery

ground, which could result in heat

damage and consequent smoke or fire

on the airplane.

DATES: Effective June 10, 1998.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of June 10,

1998.

ADDRESSES: The service information

referenced in this AD may be obtained

from Boeing Commercial Airplane

Group, P.O. Box 3707, Seattle,

Washington 98124–2207. This

information may be examined at the

Federal Aviation Administration (FAA),

transport Airplane Directorate, Rules

Docket, 1601 Lind Avenue, SW.,

Renton, Washington; or at the Office of

the Federal Register, 800 North Capitol

Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Forrest Keller, Senior Aerospace

Engineer, Systems and Equipment

Branch, ANM–130S, FAA, Seattle

Aircraft Certification Office, 1601 Lind

Avenue, SW., Renton, Washington

98055–4056; telephone (425) 227–2790;

fax (425) 227–1181.

SUPPLEMENTARY INFORMATION: A

proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) to

include an airworthiness directive (AD)

that is applicable to certain Boeing

Model 747–400 series airplanes was

published in the Federal Register on

November 25, 1997 (62 FR 62726). That

action proposed to require removal and

reconfiguration of the battery grounds of

the auxiliary power unit (APU).

Interested persons have been afforded

an opportunity to participate in the

making of this amendment. Due

consideration has been given to the

comments received.

Support for the Proposal

One commenter supports the

proposal.

Request To Extend the Compliance

Time

The Air Transport Association (ATA)

of America, on behalf of one of its

members, requests that the proposed

compliance time be extended to allow

the modification to be accomplished

within 12 months, rather than 6 months.

This ATA member operates the largest

number of U.S.-registered 747–400

airplanes. The ATA member claims that

such an extension is warranted in light

of the amount of time required for

preparation and accomplishment of the

actions required by this proposed AD,

and in light of the results of inspections

to detect discrepancies of the APU

battery grounds performed subsequent

to receipt of and in accordance with

Boeing telex M–7240–96–0927, dated

May 24, 1996. The ATA member

maintains that the results of this

inspection indicated that the APU

grounds on its airplanes that are the

subject of the unsafe condition of this

proposed AD were retorqued and found

to be free of discrepancies.

The FAA concurs with the

commenter’s request to extend the

compliance time from 6 months to 12

months. In light of the information

presented by the commenter, the FAA

finds that such an extension will allow

the modification to be performed with

minimal effect on the maintenance

schedule and no adverse effect on

safety. Paragraph (a) of the final rule has

been revised to specify a compliance

time of 12 months.