Federal Register / Vol. 66, No. 248 / Thursday, December 27, 2001 / Proposed Rules 66821

uncontained engine failure and damage to

the airplane, do the following:

(a) Within 30 days after the effective date

of this AD, revise the manufacturer’s Time

Limits section (TLS) of the manufacturer’s

engine manual, as appropriate for PW

PW2037, PW2040, PW2037M, PW2240,

PW2337, PW2043, PW2643, and PW2143

series turbofan engines, and for air carriers

revise the approved continuous

airworthiness maintenance program, by

adding the following:

‘‘MANDATORY INSPECTIONS

(1) Perform inspections of the following

parts at each piece-part opportunity in

accordance with the instructions provided in

PW2000 Engine Manuals 1A6231 and

1B2412:

Nomenclature Part

number

EM manual

section Inspection check Subtask

Hub, LPC Assembly ............................................................................. ALL ...... 72–31–04 ..... –06.

Disk, HPT 1st Stage ............................................................................. ALL ...... 72–52–02 ..... FPI entire disk per 72–52–00,

Inspection/Check–02.

72–52–02–

230–007

Hub, HPT 2nd Stage ............................................................................ ALL ...... 72–52–16 ..... Fpi entire hub per 72–52–00,

Inspection/Check–02.

72–52–16–

230–007

Hub, HPC Front .................................................................................... ALL ...... 72–35–02 ..... –05.

Disk, HPC Drum Rotor Assembly (7–15) ............................................. ALL ...... 72–35–03 ..... –04 .........................................

Disk, HPC Drum Rotor Assembly (16–17) ........................................... ALL ...... 72–35–10 ..... –05 .........................................

Disk, HPC 16th Stage .......................................................................... ALL ...... 72–35–06 ..... –04 .........................................

Disk, HPC 17th Stage .......................................................................... ALL ...... 72–35–07 ..... –04 .........................................

LPC Drive Turbine Shaft ...................................................................... ALL ...... 72–32–01 ..... –06 .........................................

Hub, Turbine Rear ................................................................................ ALL ...... 72–53–81 ..... –06 .........................................

Disk, LPT 3rd Stage ............................................................................. ALL ...... 72–53–31 ..... –01 .........................................

Disk, LPT 4th Stage ............................................................................. ALL ...... 72–35–41 ..... –01 .........................................

Disk, LPT 5th Stage ............................................................................. ALL ...... 72–32–51 ..... –01 .........................................

Disk, LPT 6th Stage ............................................................................. ALL ...... 72–53–61 ..... –01 .........................................

Disk, LPT 7th Stage ............................................................................. ALL ...... 72–53–71 ..... –01 .........................................

(2) For the purposes of these mandatory

inspections, piece-part opportunity means:

(i) The part is considered completely

disassembled when done in accordance with

the disassembly instructions in the

manufacturer’s engine manual to either part

number level listed in the table above, and

(ii) The part has accumulated more than

100 cycles in service since the last piece-part

opportunity inspection, provided that the

part was not damaged or related to the cause

for its removal from the engine.’’

(b) Except as provided in paragraph (e) of

this AD, and notwithstanding contrary

provisions in § 43.16 of Federal Aviation

Regulations (14 CFR 43.16), these enhanced

inspections must be performed only in

accordance with the TLS of the appropriate

PW2000 series engine manuals.

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 must

submit their requests through an appropriate

FAA Principal Maintenance Inspector (PMI),

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.

Special Flight Permits

(d) 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 done.

(e) FAA-certificated air carriers that have

an approved continuous airworthiness

maintenance program in accordance with the

record keeping requirement of § 121.369 (c)

of the Federal Aviation Regulations (14 CFR

121.369 (c)) of this chapter must maintain

records of the mandatory inspections that

result from revising the Time Limits section

of the Instructions for Continuous

Airworthiness (ICA) and the air carrier’s

continuous airworthiness program.

Alternatively, certificated air carriers may

establish an approved system of record

retention that provides a method for

preservation and retrieval of the maintenance

records that include the inspections resulting

from this AD, and include the policy and

procedures for implementing this alternate

method in the air carrier’s maintenance

manual required by § 121.369 (c) of the

Federal Aviation Regulations (14 CFR

121.369 (c)); however, the alternate system

must be accepted by the appropriate PMI and

require the maintenance records be

maintained either indefinitely or until the

work is repeated. Records of the piece-part

inspections are not required under § 121.380

(a)(2)(vi) of the Federal Aviation Regulations

(14 CFR 121.380 (a)(2)(vi)). All other

operators must maintain the records of

mandatory inspections required by the

applicable regulations governing their

operations.

Issued in Burlington, Massachusetts, on

December 17, 2001.

Jay J. Pardee,

Manager, Engine and Propeller Directorate,

Aircraft Certification Service.

[FR Doc. 01–31557 Filed 12–26–01; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001–SW–40–AD]

RIN 2120–AA64

Airworthiness Directives; MD

Helicopters, Inc. Model 369D, 369E,

369F, and 369FF Helicopters

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

adoption of a new airworthiness

directive (AD) for MD Helicopters, Inc.

Model 369D, 369E, 369F, and 369FF

helicopters with a tailboom modified

according to Aerometals supplemental

type certificate (STC) SH5055NM or

SH4801NM. The AD would require an

inspection to identify the part number

(P/N) of the bolts that attach the tail

rotor gearbox to the tailboom and

replacing any bolt of inadequate grip

length with an airworthy bolt. This AD

would also require determining the

number of bolt threads protruding from

each nutplate and adding an additional

washer if more than four threads

protrude. This proposal is prompted by

the discovery that bolts of inadequate

grip length were specified to attach the

tail rotor gearbox to the tailboom. The

actions specified by the proposed AD

are intended to prevent loss of a tail

rotor gearbox due to bolts of inadequate

66822 Federal Register / Vol. 66, No. 248 / Thursday, December 27, 2001 / Proposed Rules

grip length and subsequent loss of

control of the helicopter.

DATES: Comments must be received on

or before February 25, 2002.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Office of the

Regional Counsel, Southwest Region,

Attention: Rules Docket No. 2001–SW–

40–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.

Comments may be inspected at the

Office of the Regional Counsel between

9 a.m. and 3 p.m., Monday through

Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: John

Cecil, Aviation Safety Engineer, FAA,

Los Angeles Aircraft Certification

Office, Airframe Branch, 3960

Paramount Blvd., Lakewood, California

90712–4137, telephone (562) 627–5228,

fax (562) 627–5210.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to

participate in the making of the

proposed 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 above. All

communications received on or before

the closing date for comments will be

considered before taking action on the

proposed rule. The proposals contained

in this document may be changed in

light of the comments received.

Comments are specifically invited on

the overall regulatory, economic,

environmental, and energy aspects of

the proposed 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

summarizing each FAA-public contact

concerned with the substance of this

proposal will be filed in the Rules

Docket.

Commenters wishing the FAA to

acknowledge receipt of their mailed

comments submitted in response to this

proposal must submit a self-addressed,

stamped postcard on which the

following statement is made:

‘‘Comments to Docket No. 2001–SW–

40–AD.’’ The postcard will be date

stamped and returned to the

commenter.

Availability of NPRMs

Any person may obtain a copy of this

NPRM by submitting a request to the

FAA, Office of the Regional Counsel,

Southwest Region, Attention: Rules

Docket No. 2001–SW–40–AD, 2601

Meacham Blvd., Room 663, Fort Worth,

Texas 76137.

Discussion

This document proposes adopting a

new AD for MD Helicopters, Inc. Model

369D, 369E, 369F, and 369FF

helicopters with a tailboom modified

according to either Aerometals STC

SH5055NM or SH4801NM. Yehnert

Helicopters, Inc. formerly owned both

STCs. This proposal is prompted by the

discovery that the maintenance

instructions supplied to installers of

STCs SH5055NM and SH4801NM

incorrectly specified the tail rotor

gearbox attaching bolt as P/N NAS6204–

25, which has an inadequate grip length.

This condition, if not corrected, could

result in loss of a tail rotor gearbox and

subsequent loss of control of the

helicopter.

The FAA has reviewed Aerometals

Service Bulletin SB–001, dated August

3, 2000, which describes procedures for

verifying that the proper attaching bolts

are used to install the tail rotor gearbox

to the tailboom.

We have identified an unsafe

condition that is likely to exist or

develop on other MD Helicopters, Inc.

Model 369D, 369E, 369F, and 369FF

helicopters of the same type design

modified by STC SH5055NM or

SH4801NM. Therefore, the proposed AD

would require the following:

• Inspect the tail rotor gearbox attach

bolts to determine the P/N. Replace any

bolt for which a P/N cannot be

determined and any bolt that is not P/

N NAS1304–26 before further flight.

After replacing a bolt, inspect for

loosening of the bolt torque at a

specified interval. Retorque the bolt,

reapply the slippage mark, and

reinspect the torque between 2 and 10

hours TIS thereafter.

• Remove the tailboom control rod

and determine the number of bolt

threads protruding from each nutplate

on the internal surface of the aft

tailboom frame casting. At least one

thread must protrude. If more than four

threads protrude, add an additional

washer under the bolt head.

The FAA estimates that this proposed

AD would affect 500 helicopters of U.S.

registry. The FAA estimates

approximately 1⁄2 work hour would be

required to determine whether either

STC has been installed. For the

estimated 40 helicopters that have been

modified by either STC, approximately

1 work hour per helicopter will be

required to inspect and replace the

bolts. The average labor rate is

approximately $60 per work hour.

Required parts would cost

approximately $40 per helicopter. Based

on these figures, the total cost impact of

the proposed AD on U.S. operators is

estimated to be $19,000.

The regulations proposed herein

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. Therefore,

it is determined that this proposal

would not have federalism implications

under Executive Order 13132.

For the reasons discussed above, I

certify that 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) if

promulgated, 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 copy of the draft

regulatory evaluation prepared for this

action is contained in the Rules Docket.

A copy of it may be obtained by

contacting the Rules Docket at the

location provided under the caption

ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation

safety, Safety.

The Proposed Amendment

Accordingly, pursuant to the

authority delegated to me by the

Administrator, the Federal Aviation

Administration proposes to amend 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 a new airworthiness directive to

read as follows:

MD Helicopters, Inc.: Docket No. 2001–SW–

40–AD.

Applicability: Model 369D, 369E, 369F,

and 369FF helicopters, modified in

accordance with Aerometals Supplemental

Type Certificate (STC) SH5055NM or

SH4801NM, certificated in any category.

Note 1: This AD applies to each helicopter

identified in the preceding applicability

provision, regardless of whether it has been

otherwise modified, altered, or repaired in

the area subject to the requirements of this

Federal Register / Vol. 66, No. 248 / Thursday, December 27, 2001 / Proposed Rules 66823

AD. For helicopters 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 (c) 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 loss of the tail rotor gearbox

due to attaching bolts of inadequate grip

length and subsequent loss of control of the

helicopter, accomplish the following:

(a) Within 25 hours time-in-service (TIS),

conduct the following inspections:

(1) For each tail rotor gearbox attaching

bolt (bolt):

(i) Determine the part number (P/N).

(ii) If the P/N cannot be determined or if

the bolt is not P/N NAS1304–26, before

further flight, replace the bolt with bolt, P/

N NAS1304–26.

(iii) Torque the bolt to 100–110 in-lbs and

apply a slippage mark.

(2) Remove the tailboom control rod and

determine the number of bolt threads

protruding from each nutplate on the internal

surface of the aft tailboom frame casting, P/

N 369D23503, as shown in Figure 1. At least

one thread must protrude. If more than four

threads protrude, add an additional washer,

P/N AN960D416, under the bolt head.

Torque the bolt to 100–110 in-lbs., and

reapply a slippage mark.

(b) Between 2 and 10 hours TIS after

accomplishing the requirements of paragraph

(a) of this AD, inspect the torque on each bolt

by applying 100 in-lbs. If any bolt movement

occurs, retorque the bolt to 100–110 in-lbs.

and reapply a slippage mark. Reinspect the

torque between 2 and 10 hours TIS thereafter

until no bolt movement occurs.

Note 2: Aerometals Service Bulletin SB–

001, dated August 3, 2000, pertains to the

subject of this AD.

(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, Los

Angeles Aircraft Certification Office

(LAACO), FAA. Operators shall submit their

requests through an FAA Principal

Maintenance Inspector, who may concur or

comment and then send it to the Manager,

LAACO.

Note 3: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the LAACO.

(d) Special flight permits will not be

issued.

Issued in Fort Worth, Texas, on December

14, 2001.

David A. Downey,

Manager, Rotorcraft Directorate, Aircraft

Certification Service.

[FR Doc. 01–31556 Filed 12–26–01; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001–CE–36–AD]

RIN 2120–AA64

Airworthiness Directives; Air Tractor,

Inc. AT–400, AT–500, and AT–800

Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes to

supersede Airworthiness Directive (AD)

2001–10–04 R1, which lowered the safe

life for the wing lower spar cap on