13418 Federal Register / Vol. 66, No. 44 / Tuesday, March 6, 2001 / Rules and Regulations

Cracked Disks

(6) Prior to further flight, replace cracked

disks with serviceable parts.

JT9D–7R4 Series

(b) For PW JT9D–7R4D, –7R4D1, –7R4E,

and –7R4E1 (AI–500) series turbofan engines,

with 1st stage HPT disks, P/N 825601:

Initial Inspection

(1) Perform the initial detailed ECI for

cracks in accordance with the

Accomplishment Instructions of PW ASB No.

JT9D–7R4–A72–563, dated July 28, 1999.

(2) Inspect at the following compliance

times, depending on whether parts have had

prior FPI or not.

Initial Compliance Times

No Prior FPI

(3) The following are the initial compliance

times for parts that have had no prior FPI:

(i) For disks with more than 10,000 total

part CSN on the effective date of this AD,

inspect within 250 CIS after the effective date

of this AD.

(ii) For disks with at least 8,000 CSN

though no more than 10,000 total part CSN

on the effective date of this AD, inspect

within 1,000 CIS after the effective date of

this AD.

(iii) For disks with at least 6,000 CSN

though no more than 7,999 total part CSN on

the effective date of this AD, inspect within

2,000 CIS after the effective date of this AD.

(iv) For disks with less than 6,000 total part

CSN on the effective date of this AD, inspect

prior to accumulating 8,000 total part CSN.

Prior FPI Accomplished

(4) The following are the initial compliance

times for parts that have had a previous FPI:

(i) For disks with more than 10,000 CIS

since last FPI on the effective date of this AD,

inspect within 250 CIS after the effective date

of this AD.

(ii) For disks with at least 8,000 CIS though

no more than 10,000 CIS since last FPI on the

effective date of this AD, inspect within

1,000 CIS after the effective date of this AD.

(iii) For disks with at least 6,000 CIS

though no more than 7,999 CIS since last FPI

on the effective date of this AD, inspect

within 2,000 CIS after the effective date of

this AD.

(iv) For disks with less than 6,000 CIS

since last FPI on the effective date of this AD,

inspect prior to accumulating 8,000 CIS since

last FPI on the effective date of this AD.

Repetitive Inspections

(5) Thereafter, perform detailed ECI for

cracks:

(i) At intervals not to exceed 8,000 CIS

since last ECI.

(ii) Inspect in accordance with the

Accomplishment Instructions of PW ASB No.

JT9D–7R4–A72–563, dated July 28, 1999.

Cracked Disks

(6) Prior to further flight, replace cracked

disks with serviceable parts.

Alternative Methods of Compliance

(c) 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 (ECO). Operators shall

submit their request through an appropriate

FAA Principal Maintenance Inspector, who

may add comments and then send it to the

Manager, ECO.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this airworthiness directive,

if any, may be obtained from the ECO.

Ferry Flights

(d) 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 inspection requirements

of this AD can be accomplished.

Incorporation by Reference

(e) The actions required by this AD must

be done in accordance with the following

Pratt & Whitney Alert Service Bulletins:

Document No. Pages Revision Date

JT9D A6367 ........................................................... 1–12 Original ................................................................. July 28, 1999.

Total pages: 12.

JT9D–7R4–A72–563 ............................................. 1–37 Original ................................................................. July 28, 1999.

Total pages: 37.

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 Pratt & Whitney, 400 Main Street, East

Hartford, CT 06108; telephone: 860 565–

6600, fax: 860 565–4503. 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.

Effective Date

(f) This amendment becomes effective on

May 7, 2001.

Issued in Burlington, Massachusetts, on

February 21, 2001.

David A. Downey,

Acting Manager, Engine and Propeller

Directorate, Aircraft Certification Service.

[FR Doc. 01–4890 Filed 3–5–01; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000–NE–38–AD; Amendment

39–12136; AD 2001–04–16]

RIN 2120–AA64

Airworthiness Directives; General

Electric Company CF6–50 Series

Turbofan Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule; request for

comments.

SUMMARY: This amendment supersedes

an existing airworthiness directive (AD),

applicable to General Electric Company

(GE) CF6–50 series turbofan engines.

That AD currently requires visual

inspection of the stage 2 low pressure

turbine (LPT) nozzle lock assemblies,

and replacement of the borescope plug

with a new design plug.

This amendment is prompted by a

report of an uncontained engine failure

on an engine that had complied with the

current AD. This amendment requires

additional inspections and provides

interim and terminating corrective

actions. The actions specified in this AD

are intended to detect cracked, loose or

missing stage 2 LPT nozzle lock

assembly studs that could lead to failure

of the locks, nozzle segment rotation,

LPT case machining, and subsequent

uncontained failure of the engine. The

actions also provide for modifications of

nozzle lock assemblies if the nozzle lock

studs are found cracked, loose, or

missing.

DATES: Effective March 21, 2001.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of March 21,

2001.

Comments for inclusion in the Rules

Docket must be received on or before

May 7, 2001.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), New England

Region, Office of the Regional Counsel,

Federal Register / Vol. 66, No. 44 / Tuesday, March 6, 2001 / Rules and Regulations 13419

Attention: Rules Docket No. 2000–NE–

38–AD, 12 New England Executive Park,

Burlington, MA 01803–5299. Comments

may also be sent via the Internet using

the following address: ‘‘9-aneadcomment@faa.gov.’’ Comments sent

via the Internet must contain the docket

number in the subject line. 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:

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: On

September 21, 2000, the FAA issued AD

2000–20–02, Amendment 39–11913 (65

FR 58645, October 2, 2000) to require

visual inspection of the stage 2 LPT

nozzle lock studs, and replacement of

the borescope plug with a new design

plug. That action was prompted by three

uncontained engine failures resulting

from stage 2 LPT lock stud failures,

nozzle segment rotation, and LPT case

machining. That condition, if not

corrected, could result in failure of the

stage 2 LPT nozzle lock assemblies.

Since AD 2000–20–02 was issued, there

has been one more uncontained engine

failure, on February 4, 2001, that has

been attributed to the failure of stage 2

Waspalloy LPT nozzle lock assembly

studs. That engine is reported to have

been in compliance with AD 2000–20–

02, at the time of failure. Because of this

report, and because of the recent

issuance of three GE service bulletins

(SB’s), two of which are alert service

bulletins (ASB’s), the FAA has

determined that it is necessary to

supersede AD 2000–20–02. The GE SB’s

provide for

• Stage 2 Waspalloy LPT nozzle lock

ultrasonic inspection (previously

allowed as an alternative method of

compliance (AMOC) to AD 2000–20–

02),

• LPT case modification and new

nozzle lock incorporation (previously

allowed as an AMOC to AD 2000–20–

02), and,

• Stage 2 LPT additional nozzle lock

incorporation.

The methods for complying with AD

2000–20–02 that were previously

approved as AMOCS to that AD have

been incorporated into this AD.

This AD incorporates by reference,

one SB and one ASB as-written. This

AD also incorporates by reference

another inspection ASB, but with two

exceptions. Because of the recent engine

failure, the inspection ASB is

incorporated with a reduction in the

stage 2 LPT Waspalloy nozzle lock

ultrasonic inspection thresholds, but

does not include the requirement to

inspect the stages 3 and 4 LPT nozzle

locks.

Manufacturer’s Service Information

The FAA has reviewed and approved

the technical contents of the following:

• GE ASB CF6–50 72–A1197, dated

December 14, 2000, that describes

procedures for on-wing or off-wing

initial and repetitive ultrasonic

inspections of stage 2 LPT Waspalloy

nozzle lock studs for cracks. This ASB

also defines initial and repetitive visual

inspections of stage 2 LPT Rene nozzle

lock studs.

• GE ASB CF6–50 72–A1201, dated

December 22, 2000, and CF6–50 72–

A1201, Revision 1, dated February 6,

2001, describe procedures for LPT case

modification and incorporation of new

design nozzle locks. Accomplishment of

this ASB constitutes terminating action

for the inspection requirements of this

AD.

• GE SB CF6–50 72–1203, dated

November 22, 2000, and CF6–50 72–

1203 Revision 1, dated February 7,

2001, describe procedures for

incorporating additional stage 2 LPT

nozzle locks when an engine is found to

have a reject condition as described in

GE ASB CF6–50 72–A1197, dated

December 14, 2000, and the required

compliance cannot be addressed by an

immediate shop visit.

Differences Between the Manufacturer’s

Service Information and This AD

Although GE ASB CF6–50 72–A1197,

dated December 14, 2000, requires

ultrasonic inspections of stage 2 LPT

Waspalloy nozzle lock studs to be done

at specified times, the FAA has

determined that more stringent initial

and repetitive ultrasonic inspection

time intervals are required to meet the

necessary level of safety, and have

incorporated those intervals in this

amendment. Also, although that ASB

requires the stages 3 and 4 LPT nozzle

locks to be inspected, the FAA has

determined that an unsafe condition is

not likely to occur as a result of a stage

3 or 4 lock stud failure and therefore

this AD requires only the stage 2 LPT

nozzle locks to be inspected.

Actions Required by This AD

Since an unsafe condition has been

identified that is likely to exist or

develop on other GE CF6–50 series

turbofan engines of the same type

design, this AD supersedes AD 2000–

20–02 to require:

• Installation of the solid borescope

plug for engines that have not already

complied with paragraph (e) of AD

2000–20–02.

• On-wing or off-wing initial and

repetitive ultrasonic inspections of stage

2 Waspalloy LPT nozzle lock assembly

studs for cracks.

• On-wing or off-wing initial and

repetitive visual inspections of stage 2

LPT nozzle lock assembly studs for

loose or missing studs.

• Replacement of all of the stage 2

LPT lock assemblies with new design

assemblies before further flight if a

cracked, loose, or missing stud is found,

OR,

• Incorporation of additional stage 2

LPT nozzle locks if no indications of

nozzle rotation are found, as an interim

action to allow time to arrange for a

shop visit, within 3,500 cycles-inservice.

• Inspection of the area surrounding

the borescope plug for evidence of

buckling or cracks whenever the nozzle

lock studs are inspected.

• Inspection for loose or missing

added nozzle locks and LPT case

cracking in the areas of the added

nozzle locks, every 750 hours time-inservice.

• Replacement of the LPT lock

assemblies with new design assemblies

before further flight if any LPT case

buckling or cracks are found, or if

nozzle segment rotation is found.

Immediate Adoption of This AD

Since a situation exists that requires

the immediate adoption of this

regulation, it is found that notice and

opportunity for prior public comment

hereon are impracticable, and that good

cause exists for making this amendment

effective in less than 30 days.

Comments Received

Interested persons were afforded an

opportunity to participate in the making

of Amendment 39–11913. Due

consideration has been given to the

comments received.

Change Inspection Thresholds and

Intervals

One commenter requests that the

inspection thresholds and intervals be

changed to coincide with scheduled

13420 Federal Register / Vol. 66, No. 44 / Tuesday, March 6, 2001 / Rules and Regulations

aircraft ‘‘A-Check’’ intervals, or the

manufacturer’s recommended engine

repetitive maintenance intervals.

The FAA disagrees. As the commenter

stated in their request, the ‘‘A-Check’’

interval can vary from operator to

operator. ‘‘A-Check’’ intervals as low as

200 hours to as high as 700 hours have

been reported. To provide an equivalent

level of safety for all operators, the

inspection thresholds and intervals

must therefore be defined in this AD.

Extend 30 Day Compliance

Requirement for Borescope Plug

Replacement

One commenter requests that the 30

day compliance requirement for the

borescope plug installation be extended

to 90 days or next ‘‘A-Check’’, due to

limited parts availability.

The FAA disagrees. The manufacturer

provided evidence that sufficient parts

had been procured and distributed to

support the 30 day requirement.

Editorial Correction

One commenter requests that the

word ‘‘place’’ in paragraph (d) of AD

2000–20–02 be changed to read

‘‘replace’’.

The FAA agrees. A correction was

published in the Federal Register on

October 16, 2000 (65 FR 61216).

Comments on New Amendment Invited

Although this superseding

amendment is in the form of a final rule

that involves requirements affecting

flight safety and, thus, was not preceded

by notice and an opportunity for public

comment, comments are invited on this

rule. Interested persons are invited to

comment on this rule by submitting

such written data, views, or arguments

as they may desire. Communications

should identify the Rules Docket

number and be submitted in triplicate to

the address specified under the caption

ADDRESSES. All communications

received on or before the closing date

for comments will be considered, and

this rule may be amended in light of the

comments received. Factual information

that supports the commenter’s ideas and

suggestions is extremely helpful in

evaluating the effectiveness of the AD

action and determining whether

additional rulemaking action would be

needed.

Comments are specifically invited on

the overall regulatory, economic,

environmental, and energy aspects of

the rule that might suggest a need to

modify the rule. All comments

submitted will be available, both before

and after the closing date for comments,

in the Rules Docket for examination by

interested persons. A report that

summarizes each FAA-public contact

concerned with the substance of this AD

will be filed in the Rules Docket.

Commenters wishing the FAA to

acknowledge receipt of their comments

submitted in response to this rule must

submit a self-addressed, stamped

postcard on which the following

statement is made: ‘‘Comments to

Docket Number 2000NE–38–AD.’’ The

postcard will be date stamped and

returned to the commenter.

Regulatory Impact

This final rule does not have

federalism implications, as defined in

Executive Order No. 13132, because it

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.

Accordingly, the FAA has not consulted

with state authorities prior to

publication of this rule.

The FAA has determined that this

regulation is an emergency regulation

that must be issued immediately to

correct an unsafe condition in aircraft,

and is not a ‘‘significant regulatory

action’’ under Executive Order 12866. It

has been determined further that this

action involves an emergency regulation

under DOT Regulatory Policies and

Procedures (44 FR 11034, February 26,

1979). If it is determined that this

emergency regulation otherwise would

be significant under DOT Regulatory

Policies and Procedures, a final

regulatory evaluation will be prepared

and placed in the Rules Docket. A copy

of it, if filed, 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 Title

14 of the Code of Federal 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

removing Amendment 39–11913 (65 FR

58645, October 2, 2000), and by adding

a new airworthiness directive (AD),

Amendment 39–12136, to read as

follows:

2001–04–16 General Electric Company:

Amendment 39–12136. Docket No.

2000–NE–38–AD. Supersedes AD 2000–

20–02, Amendment 39–11913.

Applicability. This airworthiness directive

(AD) is applicable to General Electric

Company (GE) CF6–50 series turbofan

engines. These engines are installed on, but

not limited to, Airbus Industries A300,

Boeing Airplane Company 747, and

McDonnell Douglas Corporation DC10

airplanes.

Note 1: This 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 (l) 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. Compliance with this AD is

required as indicated, unless already done.

To detect cracked, loose, or missing stage

2 low pressure turbine (LPT) nozzle lock

assembly studs that could lead to failure of

the locks, segment rotation, LPT case

machining, and subsequent uncontained

failure of the engine, do the following:

Installation of Solid Borescope Plug

(a) For engines that have not already

complied with paragraph (e) of AD 2000–20–

02, install a stage 2 LPT solid borescope

inspection plug part number (P/N)

2083M99P01, or a plug with the alternate P/

N’s 305–381–303–0 or 2110M79P01, before

further flight, unless paragraph (e)(1) (GE

Alert Service Bulletin (ASB) CF6–50 72–

A1201, or CF6–50 72–A1201, Revision 1) of

this AD has already been accomplished.

Visual Inspection of Stage 2 Nozzle Lock

Assemblies

(b) For engines with stage 2 LPT Rene 41

nozzle lock assemblies, visually inspect locks

for loose or missing studs, in accordance

with Paragraph 3.B., Accomplishment

Instructions of GE ASB CF6–50 72–A1197,

dated December 14, 2000, within the

following times:

Federal Register / Vol. 66, No. 44 / Tuesday, March 6, 2001 / Rules and Regulations 13421

TABLE 1.—RENE 41 STAGE 2 NOZZLE LOCK ASSEMBLIES

Time on Rene 41 lock assembly Inspect within Repetitive inspect within

(1) Less than 4,000 hours time-since-new (TSN) on the effective date

of this AD.

750 hours after accumulating

4,000 hours TSN.

750 hours time-since-last inspection (TSLI).

(2) 4,000 hours TSN or greater, or if TSN is not known, on the effective date of this AD.750 hours TIS after the effective

date of this AD.

750 hours TSLI.

(c) For engines with stage 2 LPT Waspalloy nozzle lock assemblies, visually inspect for loose or missing studs within the following

times:

TABLE 2.—WASPALLOY STAGE 2 NOZZLE LOCK ASSEMBLIES

Time on Stage 2 Waspalloy lock assembly Initial inspect within Repetitive inspect within

(1) Less than 1,250 hours TSN on the effective date of this AD ........... 750 hours after accumulating

1,250 hours TSN.

750 hours TSLI.

(2) Greater than or equal to 1,250 hours TSN, but less than 4,000

hours TSN on the effective date of this AD.

750 hours TIS after the effective

date of this AD.

750 hours TSLI.

(3) 4,000 hours TSN or greater, on the effective date of this AD, or, if

hours unknown.

250 hours TIS after the effective

date of this AD.

750 hours TSLI.

Ultrasonic Inspection of Stage 2 LPT

Waspalloy Nozzle Lock Assemblies

(d) For engines with stage 2 LPT Waspalloy

nozzle lock assemblies with no loose or

missing studs found in accordance with

paragraph (c) of this AD, ultrasonically

inspect studs for cracks in accordance with

Paragraph 3.A., Accomplishment Instructions

of GE ASB CF6–50 72–A1197, dated

December 14, 2000, within the times

identified in paragraph (c) of this AD.

Corrective Action

(e) For engines with either stage 2 LPT

Rene 41 or Waspalloy nozzle lock assemblies

where the assembly studs are found loose or

missing, do one of the following:

(1) Prior to further flight, modify the LPT

case and install new design nozzle locks as

specified in GE ASB CF6—50 72-A1201,

dated December 22, 2000, or CF6—50 72-

A1201, Revision 1, dated February 6, 2001;

or

(2) Prior to further flight, as an interim onwing action for stage 2 LPT nozzle locks

only, modify the LPT case and install seven

additional nozzle locks as specified in GE

service bulletin CF6–50 72–1203, dated

November 22, 2000, or CF6–50 72–1203,

Revision 1, dated February 7, 2001, providing

the following conditions are met prior to

modification:

(i) There are no cracks or distortion in the

stage 2 borescope plug area of the LPT case.

(ii) The borescope plug is able to be

removed.

(iii) There is no evidence of stage 2 nozzle

segment rotation, as evidenced by a

borescope inspection that reveals that no

nozzle segment circumferential gap is greater

than 0.250 inch.

(f) For engines with stage 2 LPT nozzle

lock assemblies modified in accordance with

paragraph (e)(2) of this AD, perform the

following inspections every 750 hours TIS,

until the engine is modified in accordance

with paragraph (e)(1) of this AD:

(1) Repetitive visual inspections of the

seven additional nozzle locks for loose or

missing locks.

(2) Repetitive visual inspections of the LPT

case in the area of the additional locks for

cracks.

(3) Repetitive visual inspections of the LPT

case in the area of the borescope plug for

cracks.

Note 2: Modification of the LPT case and

installation of the additional locks per

paragraph (e)(2) of this AD should not be

performed by the same individual for all

engines installed on the same airplane prior

to the same flight.

(g) Engines rejected by the inspections in

paragraph (f) of this AD are not serviceable

and must be modified in accordance with

paragraph (e)(1) of this AD prior to further

flight.

(h) Modification of the LPT case in

accordance with paragraph (e)(2) of this AD

establishes a life limit for LPT case P/N’s

2083M38G01, 2083M38G02, 2083M38G03,

2083M38G04, 2083M38G05, 2083M38G06,

2083M38G07, and 2083M38G08, of 3,500 CIS

since modification.

(i) Except as required in paragraph (j) of

this AD, for engines with stage 2 LPT

Waspalloy nozzle lock assemblies where one

or more studs are found cracked by the

inspections in paragraph (d) of this AD, but

where no two cracked studs are located

adjacent to each other, continued operation

for an additional 25 hours time-in-service,

maximum, is allowed prior to performing one

of the corrective actions in paragraph (e) of

this AD.

(j) For engines with two or more adjacent

stage 2 LPT Waspalloy nozzle lock studs

found cracked by the inspections in

paragraph (d) of this AD, do one of the

corrective actions in paragraph (e) of this AD

prior to further flight.

Note 3: After installation of new design

nozzle locks in accordance with paragraph

(e)(1) of this AD, any solid borescope plug

may be replaced with the standard borescope

plug if the operator so chooses.

Terminating Action

(k) Accomplishment of Paragraphs 3.A.

through 3.E.(2) of GE ASB CF6–50 72–A1201,

dated December 22, 2000, or CF6–50 72–

A1201, Revision 1, dated February 6, 2001

(modification of the LPT case and installation

of new design nozzle locks per paragraph

(e)(1) of this AD), is terminating action for the

inspection requirements of this AD.

Alternative Methods of Inspection

(l) 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 (ECO). Operators shall

submit their requests through an appropriate

FAA Principal Maintenance Inspector, who

may add comments and then send it to the

Manager, ECO.

Note 4: Information concerning the

existence of approved alternative methods of

compliance with this airworthiness directive,

if any, may be obtained from the ECO.

Special Flight Permits

(m) 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.

Incorporation by Reference Material

(n) The actions required by this AD shall

be done in accordance with the following

General Electric Co. alert service bulletins

(ASB) and service bulletin (SB):

13422 Federal Register / Vol. 66, No. 44 / Tuesday, March 6, 2001 / Rules and Regulations

Document Pages Revision Date

ASB CF6–50 72–A1197 .................................................................................................... 1–28 Original ............. December, 14, 2000.

Total pages: 28

ASB CF6–50 72–A1201 .................................................................................................... 1–21 Original ............. December 22, 2000.

Total pages: 21

ASB CF6–50 72–A1201 .................................................................................................... 1–22 1 ....................... February 6, 2001.

Total pages: 22

SB CF6–50 72–1203 ......................................................................................................... 1–9 Original ............. November 22, 2000.

Total pages: 9

SB CF6–50 72–1203 ......................................................................................................... 1–12 1 ....................... February 7, 2001.

Total pages: 12

The incorporations by reference were

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.

Effective Date

(o) This amendment becomes effective on

March 21, 2001.

Issued in Burlington, Massachusetts, on

February 23, 2001.

Jay J. Pardee,

Manager, Engine and Propeller Directorate,

Aircraft Certification Service.

[FR Doc. 01–4939 Filed 3–5–01; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001–SW–01–AD; Amendment

39–12134; AD 2001–03–51]

RIN 2120–AA64

Airworthiness Directives; Sikorsky

Aircraft Corporation Model S–76B and

S–76C Helicopters

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)

2001–03–51, which was sent previously

to all known U.S. owners and operators

of Sikorsky Aircraft Corporation

(Sikorsky) Model S–76B and S–76C

helicopters by individual letters. This

AD requires, for certain main rotor

shafts, initial and recurring fluorescent

penetrant inspections. Replacing each

affected main rotor shaft (shaft) on or

before reaching 1,000 hours time-inservice (TIS) is also required. This

amendment is prompted by four reports

of shaft cracks. The actions specified by

this AD are intended to prevent failure

of the shaft and subsequent loss of

control of the helicopter.

DATES: Effective March 21, 2001, to all

persons except those persons to whom

it was made immediately effective by

Emergency AD 2001–03–51, issued on

January 30, 2001, 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 March 21,

2001.

Comments for inclusion in the Rules

Docket must be received on or before

May 7, 2001.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Office of the

Regional Counsel, Southwest Region,

Attention: Rules Docket No. 2001–SW–

01–AD, 2601 Meacham Blvd., Room

663, Fort Worth, Texas 76137. You may

also send comments electronically to

the Rules Docket at the following

address: 9-asw-adcomments@faa.gov.

The applicable service information

may be obtained from Sikorsky Aircraft

Corporation, Attn: Manager,

Commercial Tech Support, 6900 Main

Street, Stratford, Connecticut 06614,

phone (203) 386–3001, fax (203) 386–

5983. This information may be

examined at the FAA, Office of the

Regional Counsel, Southwest Region,

2601 Meacham Blvd., Room 663, Fort

Worth, Texas; or at the Office of the

Federal Register, 800 North Capitol

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

FOR FURTHER INFORMATION CONTACT:

Wayne Gaulzetti, Aviation Safety

Engineer, Boston Aircraft Certification

Office, 12 New England Executive Park,

Burlington, MA 01803, telephone (781)

238–7156, fax (781) 238–7199.

SUPPLEMENTARY INFORMATION: On

January 30, 2001, the FAA issued

Emergency AD 2001–03–51 for Sikorsky

Model S–76B and S–76C helicopters,

which requires, for certain shafts, initial

and recurring fluorescent penetrant

inspections. Replacing each affected

shaft on or before reaching 1,000 hours

TIS is also required. That action was

prompted by four reports of shaft cracks.

This condition, if not corrected, could

result in failure of the shaft and

subsequent loss of control of the

helicopter.

The FAA has reviewed Sikorsky Alert

Service Bulletin (ASB) No. 76–66–32A,

Revision A, dated January 17, 2001,

which specifies identifying main gear

box assemblies containing certain

shafts, conducting a recurring

fluorescent penetrant inspection (FPI),

and removing certain main gear box

assemblies containing certain shafts.

Since the unsafe condition described

is likely to exist or develop on other

Sikorsky Model S–76B and S–76C

helicopters of the same type designs, the

FAA issued Emergency AD 2001–03–51

to prevent failure of the shaft and

subsequent loss of control of the

helicopter. The AD requires, for certain

main rotor shafts, an FPI before further

flight and thereafter at intervals not to

exceed 20 hours TIS or 80 landings,

whichever occurs first. Replacing each

affected shaft on or before reaching

1,000 hours TIS is also required. The

actions must be accomplished in

accordance with the ASB described

previously. The short compliance time

involved is required because the

previously described critical unsafe

condition can adversely affect the

structural integrity of the helicopter.

Therefore, FPI’s and removal of each

affected shaft are required at the

specified time intervals, and this AD

must be issued immediately.

Since it was found that immediate

corrective action was required, notice

and opportunity for prior public

comment thereon were impracticable

and contrary to the public interest, and

good cause existed to make the AD

effective immediately by individual

letters issued on January 30, 2001, to all

known U.S. owners and operators of