Federal Register / Vol. 65, No. 114 / Tuesday, June 13, 2000 / Rules and Regulations 37009

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98–ANE–32–AD; Amendment

39–11760; AD 2000–11–12]

RIN 2120–AA64

Airworthiness Directives; General

Electric Company CF6–45/50 Series

Turbofan Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment adopts a

new airworthiness directive (AD) that is

applicable to General Electric Company

CF6–45/50 series turbofan engines. This

AD requires initial and repetitive

inspections for cracks in the stage 14

high pressure compressor (HPC) disk

lock slots, and removal from service of

certain disks, at the first piece-part level

or HPC rotor disassembly level

exposure, after 6,000 cycles since new

(CSN). This amendment is prompted by

reports of stage 14 HPC disk lock slot

cracks discovered during shop

fluorescent penetrant inspections. The

actions specified by this AD are

intended to prevent stage 14 HPC disk

failure, which could result in an

uncontained engine failure and damage

to the aircraft.

DATES: Effective date August 14, 2000.

The incorporation by reference of

certain publications listed in the rule is

approved by the Director of the Federal

Register as of August 14, 2000.

ADDRESSES: The service information

referenced in this AD may be obtained

from General Electric Company via

Lockheed Martin Technology Services,

10525 Chester Road, Suite C, Cincinnati,

Ohio 45215, telephone (513) 672–8400,

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:

William S. Ricci, Aerospace Engineer,

Engine Certification Office, FAA, Engine

and Propeller Directorate, 12 New

England Executive Park, Burlington, MA

01803–5299; telephone (781) 238–7742,

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 CF6–45/50 series turbofan

engines was published in the Federal

Register on October 26, 1999 (64 FR

57606). That action proposed to require

initial and repetitive inspections for

cracks in the stage 14 high pressure

compressor (HPC) disk lock slots, and

removal from service of certain disks, at

the first piece-part level or HPC rotor

disassembly level exposure, after 6,000

cycles since new (CSN).

Comments Received

Interested persons have been afforded

an opportunity to participate in the

making of this amendment. Due

consideration has been given to the

comments received.

Cost Impact

Two comments suggest that the

financial impact is not representative of

the replacement cost of the disk since

the disk is no longer in production or

stocked and the replacement cost of the

stage 11–14 spool shaft is more than

$250,000. The FAA does not agree. Over

the course of the inspection program,

the availabilty of HPC rear shafts, and

not the availability of stage 14 disks, is

expected to be the limiting factor,

requiring the installation of the stage

11–14 spool shaft. In addition, the

estimate of economic impact was based

on the lost life of the stage 14 disk only.

Reporting Period

One comment suggests that the time

limit for reporting the results of

inspections that equal or exceed the

reject criteria be increased from within

five days of the inspection to within ten

days of the inspection. The FAA does

not agree. Based on the potential

criticality of a reject finding, five days

is considered reasonable and is

consistent with reporting requirements

in ADs dealing with other critical

rotating parts. Carriers can make

arrangements with inspection facilities

to report reject findings directly to the

FAA if reporting to the carrier first

would cause a delay in reporting to the

FAA. Reports can be made to the FAA

by fax on weekends and holidays. The

FAA has included the telephone and fax

numbers for the ECO in paragraph (h) of

the Compliance Section.

Consistent Wording

One comment asks that the FAA use

consistent wording with regard to the

term ‘‘rotor module level exposure.’’

The FAA agrees. The term ‘‘rotor

module level exposure’’ has been

changed to ‘‘rotor disassembly level

exposure’’ in the Summary and in

paragraphs (f) and (i) (1) of the

Compliance Section.

Replacement of the Fan Forward Case

One comment requests that the FAA

add a provision for the definition of an

engine shop visit to paragraph (i) for

‘‘Introduction of an engine into a shop

solely for replacement of the fan

forward case.’’ The FAA agrees. To be

consistent with AD 99–24–15, the 3–9

spool AD, paragraph (i)(3)(iv),

‘‘Introduction of an engine into a shop

solely for replacement of the fan

forward case,’’ has been inserted into

the compliance section of this AD and

the paragraph previously numbered (I)

(3) (iv) has been renumbered (i)(3)(v).

Effective Date

One comment notes that the effective

date should be changed so that it is

consistent with the schedule provided

by the service bulletin. The FAA does

not agree. The rulemaking process is a

formal legal course of action that does

not include provisions for coordinating

effective dates with manufacturers’

service bulletins.

Support of the AD as Written

Three comments support the AD as

written.

Conclusion

After careful review of the available

data, including the comments 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.

Economic Analysis

There are approximately 1,538

engines of the affected design in the

worldwide fleet. The FAA estimates that

460 engines installed on aircraft of U.S.

registry would be affected by this

proposed AD, that it would take

approximately 22 work hours per engine

to accomplish the proposed actions, and

that the average labor rate is $60 per

work hour. Required parts would cost

approximately $3,600 per engine. Based

on these figures, the total cost impact of

the proposed AD on U.S. operators is

estimated to be $2,263,200.

Regulatory Impact

This rule does not have federalism

implications, as defined in Executive

Order 13132, because it does 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. Accordingly, the

37010 Federal Register / Vol. 65, No. 114 / Tuesday, June 13, 2000 / Rules and Regulations

FAA has not consulted with state

authorities prior to publication of this

rule.

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 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:

2000–11–12 General Electric Company:

Amendment 39–11760. Docket 98–ANE–

32–AD.

Applicability: General Electric Company

(GE) Model CF6–45/50 series turbofan

engines, installed on but not limited to

Airbus Industrie A300 series, Boeing

Company 747 series, and McDonnell Douglas

Corporation DC–10 series airplanes

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 (j)

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.

Compliance: Required as indicated, unless

accomplished previously.

To prevent a stage 14 high pressure

compressor (HPC) disk failure, which could

result in uncontained engine failure and

damage to the aircraft, accomplish the

following:

Inspections

(a) Perform initial inspections of HPC stage

14 disks, part numbers (P/N’s) 9080M34P03,

9080M34P04, 9080M34P05 and

9349M91P04, with serial number (SN)

prefixes GWN, MPO, RRY, and SNL, and disk

SN’s SNE00001 through SNE00017, and disk

SN’s SNE01101 through SNE01110, in

accordance with paragraphs 2.A. through 2.B.

of GE CF6–50 ASB No. 72–A1144, dated

March 19, 1998, or ASB No. 72–A1144,

Revision 1, dated May 13, 1999, and the

following schedule:

(1) Inspect disks with 6,500 cycles since

new (CSN) or less on the effective date of this

AD before accumulating 9,800 CSN.

(2) Inspect disks with more than 6,500 CSN

on the effective date of this AD no later than

the next engine shop visit (ESV) after the

effective date of this AD or before

accumulating an additional 3,300 cycles-inservice (CIS) after the effective date of this

AD, whichever occurs first.

(b) Perform repetitive inspections of HPC

stage 14 disks, P/N’s 9080M34P03,

9080M34P04, 9080M34P05 and

9349M91P04, with SN prefixes GWN, MPO,

RRY, and SNL, and disk SN’s SNE00001

through SNE00017, and disk SN’s SNE01101

through SNE01110, in accordance with

paragraphs 2.A. through 2.B. of GE CF6–50

ASB No. 72–A1144, dated March 19, 1998, or

ASB No. 72–A1144, Revision 1, dated May

13, 1999, and the following schedule:

(1) For disks with less than 9,800 CSN at

the time of the last inspection, perform

repetitive inspections no later than 9,800

CSN or before accumulating 3,300 cycles

since last inspection (CSLI), whichever

occurs later.

(2) For disks with 9,800 CSN or greater at

the time of the last inspection, perform

repetitive inspections no later than 3,300

CSLI.

(c) Perform initial inspections of HPC stage

14 disks, P/N’s 9080M34P03, 9080M34P04,

9080M34P05 and 9349M91P04 with SN

prefixes SNG and SNE, except disk SN’s

SNE00001 through SNE00017 and SNE01101

through SNE01110, in accordance with

paragraphs 2.A. through 2.B. of GE CF6–50

ASB No. 72–A1144, dated March 19, 1998, or

ASB No. 72–A1144, Revision 1, dated May

13, 1999, and the following schedule:

(1) Inspect disks with 4,200 CSN or less on

the effective date of this AD before

accumulating 7,500 CSN.

(2) Inspect disks with more than 4,200 CSN

but less than 9,000 CSN on the effective date

of this AD at the next ESV after the effective

date of this AD, before accumulating an

additional 3,300 CIS after the effective date

of this AD, or before accumulating 11,000

CSN, whichever occurs first.

(3) Inspect disks with 9,000 CSN or greater

on the effective date of this AD, at the next

ESV after the effective date of this AD, or

before accumulating an additional 2,000 CIS

after the effective date of this AD, whichever

occurs first.

(d) Perform repetitive inspections of HPC

stage 14 disks, P/N’s 9080M34P03,

9080M34P04, 9080M34P05 and 9349M91P04

with SN prefixes SNG and SNE, except disk

SN’s SNE00001 through SNE00017 and

SNE01101 through SNE01110, in accordance

with paragraphs 2.A. through 2.B. of GE CF6–

50 ASB No. 72–A1144, dated March 19,

1998, or ASB No. 72–A1144, Revision 1,

dated May 13, 1999, and the following

schedule:

(1) For disks with less than 7,500 CSN at

the time of the last inspection, perform

repetitive inspections no later than 7,500

CSN or before accumulating 3,300 CSLI,

whichever occurs later.

(2) For disks with 7,500 CSN or greater at

the time of the last inspection, perform

repetitive inspections no later than 3300

CSLI.

Removal From Service

(e) Remove from service prior to further

flight stage 14 HPC disks that equal or exceed

the reject criteria established by GE CF6–50

ASB 72–A1144, dated March 19, 1998, or

ASB No. 72–A1144, Revision 1, dated May

13, 1999.

(f) Remove from service, HPC stage 14

disks, P/N’s 9080M34P03, 9080M34P04,

9080M34P05 and 9349M91P04 with SN

prefixes SNG and SNE, except disk SN’s

SNE00001 through SNE00017 and SNE01101

through SNE01110, with greater than 6,000

CSN after the effective date of this AD, at the

next piece-part level exposure or at the next

HPC rotor disassembly level exposure after

the effective date of this AD.

Terminating Action

(g) Replacement of the stage 14 HPC disk,

P/N’s 9080M34P03, 9080M34P04,

9080M34P05, 9349M91P04, with a stage 11–

14 spool shaft is terminating action for the

inspection requirements of this AD.

Reporting Requirements

(h) Report the results of inspections that

equal or exceed the reject criteria within five

days of the inspection to: Manager, Engine

Certification Office, FAA, Engine and

Propeller Directorate, 12 New England

Executive Park, Burlington, MA 01803–5299,

telephone, (781) 238–7141, fax, (781) 238–

7199. The following information must be

included in the report:

(1) HPC Stage 14 rotor disk P/N,

(2) HPC Stage 14 rotor disk SN,

(3) HPC Stage 14 rotor disk CSN,

(4) HPC Stage 14 rotor disk CSLI, and

(5) Date and location of inspection.

Reporting requirements have been approved

by the Office of Management and Budget

(OMB) and assigned OMB control number

2120–0056.

Definitions

(i) For the purpose of this AD, the

following definitions apply:

(1) HPC Rotor disassembly occurs if any of

the HPC Rotor bolted flange joints are

separated, such as the Stage 2 joint to

accomplish the Stage 3–9 Spool inspection.

Federal Register / Vol. 65, No. 114 / Tuesday, June 13, 2000 / Rules and Regulations 37011

(2) Piece-part exposure is defined as

disassembly and removal of the stage 14 disk

from the HPC rotor structure, regardless of

any blades, locking lugs, bolts or balance

weights assembled to the disk.

(3) An engine shop visit is defined as the

introduction of an engine into a shop when

a major engine flange is separated. The

following maintenance actions are not

considered engine shop visits for the purpose

of this AD:

(i) Introduction of an engine into a shop

solely for removal or replacement of the

Stage 1 Fan Disk;

(ii) Introduction of an engine into a shop

solely for replacement of the Turbine Rear

Frame;

(iii) Introduction of an engine into a shop

solely for replacement of the Accessory

Gearbox or Transfer Gearboxes;

(iv) Introduction of an engine into a shop

solely for replacement of the Fan Forward

Case.

(v) Introduction of an engine into a shop

for any combination of exceptions specified

in paragraphs (i)(3)(i) through (i)(3)(iv);

Alternative Methods of Compliance

(j) 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 request through an appropriate FAA

Principal Maintenance Inspector, who may

add comments and then send it to the

Manager, Engine Certification Office.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this airworthiness directive,

if any, may be obtained from the Engine

Certification Office.

Incorporation by Reference

(k) The inspections shall be done in

accordance with paragraphs 2.A. through 2.B.

of GE CF6–50 ASB No. 72–A1144, dated

March 19, 1998, or ASB No. 72–A1144,

Revision 1, dated May 13, 1999, 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 via Lockheed Martin

Technology Services, 10525 Chester Road,

Suite C, Cincinnati, Ohio 45215, telephone

(513) 672–8400, 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.

Special Flight Permit

(l) Special flight permits may be issued in

accordance with §§ 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.

Effective Date of This AD

(m) This amendment becomes effective on

August 14, 2000.

Issued in Burlington, Massachusetts, on

May 25, 2000.

Thomas A. Boudreau,

Acting Manager, Engine and Propeller

Directorate, Aircraft Certification Service.

[FR Doc. 00–14017 Filed 6–12–00; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000–NM–138–AD; Amendment

39–11770; AD 2000–10–51]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 767 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule; request for

comments.

SUMMARY: This document publishes in

the Federal Register an amendment

adopting airworthiness directive (AD)

2000–10–51 that was sent previously to

all known U.S. owners and operators of

certain Boeing Model 767 series

airplanes by individual notices. This AD

requires a one-time inspection to

determine whether certain bolts are

installed in the side load underwing

fittings on both struts, and various

follow-on actions, if necessary. This

action is prompted by a report that two

fractured bolts and one cracked bolt

were found in the side load underwing

fittings. The actions specified by this

AD are intended to detect and correct

cracking or fracturing of the tension

bolts on the side load underwing fittings

on the strut, which would eventually

result in loss of the strut.

DATES: Effective June 19, 2000, to all

persons except those persons to whom

it was made immediately effective by

emergency AD 2000–10–51, issued May

18, 2000, which contained the

requirements of this amendment.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of June 19,

2000.

Comments for inclusion in the Rules

Docket must be received on or before

August 14, 2000.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 2000–NM–

138–AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056.

The applicable service information

may be obtained from Boeing

Commercial Airplane Group, P.O. Box

3707, Seattle, Washington 98124–2207.

This information may be examined at

the FAA, Transport Airplane

Directorate, 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:

James Rehrl, Aerospace Engineer,

Airframe Branch, ANM–120S, FAA,

Transport Airplane Directorate, Seattle

Aircraft Certification Office, 1601 Lind

Avenue, SW., Renton, Washington

98055–4056; telephone (425) 227–2783;

fax (425) 227–1181.

SUPPLEMENTARY INFORMATION: On May

18, 2000, the FAA issued emergency AD

2000–10–51, which is applicable to

certain Boeing Model 767 series

airplanes.

On May 15, 2000, the FAA received

a report indicating that an operator

found two fractured bolts and one

cracked bolt in the side load underwing

fittings of a Model 767–200 series

airplane. On the affected airplane, both

tension bolts on the outboard side load

underwing fitting were completely

fractured, and one bolt on the inboard

side load underwing fitting was cracked.

The affected airplane had accumulated

65,759 total flight hours and 17,021 total

flight cycles. The cracking and

fracturing of the tension bolts is due to

stress corrosion. The tension bolts are

made of H–11 steel material, which

service history has shown to be

susceptible to stress corrosion. Fracture

of the tension bolts in the side load

underwing fittings, if not corrected,

would eventually result in loss of the

strut.

Explanation of Relevant Service

Information

The FAA has reviewed and approved

Boeing Alert Service Bulletin 767–

57A0074, dated May 17, 2000, and

Revision 1, dated May 18, 2000, which

describes procedures for a one-time

inspection to determine whether H–11

steel tension bolts are installed in the

side load underwing fittings on both

struts. If any H–11 bolts are found, or if

the type of bolt cannot be determined,

the alert service bulletin also describes

procedures for repetitive ultrasonic

inspections to detect cracking or

fracturing of the tension bolts in the side

load underwing fittings on both struts,

and corrective action, if necessary.

Corrective action involves replacement

of both tension bolts in the affected side

load underwing fitting with new,

improved bolts. The new, improved