25124 Federal Register / Vol. 60, No. 91 / Thursday, May 11, 1995 / Rules and Regulations

of control of the helicopter, accomplish the

following:

(a) Before further flight, after the effective

date of this AD, verify that the tail rotor

control system is rigged in accordance with

the applicable maintenance manual.

(b) Before further flight, and thereafter at

intervals not to exceed 400 torque events,

disassemble the affected 42-degree gearbox

and inspect for cracks at the roots of the gear

teeth on the pinion, P/N 204–040–500–007 or

–009, and gear, P/N 204–040–500–008 or

–010, using a fluorescent penetrant

inspection method in accordance with the

applicable maintenance manual. Only post

emulsified fluorescent penetrant inspection

materials (Type I, Method B or D, Sensitivity

Level 3 or greater) are approved for use. A

torque event is defined as a takeoff or a lift

(internal or external).

(c) If any crack is found at the roots of the

gear teeth on the pinion or gear, replace the

pinion or gear with an airworthy pinion or

gear in accordance with the applicable

maintenance manual.

(d) Create a component history card for the

42-degree gearbox. Record the number of

torque events on a daily basis.

(e) An alternative method of compliance or

adjustment of the compliance time that

provides an acceptable level of safety may be

used when approved by the Manager,

Rotorcraft Certification Office, FAA,

Rotorcraft Directorate. Operators shall submit

their requests through an FAA Principal

Maintenance Inspector, who may concur or

comment and then send it to the Manager,

Rotorcraft Certification Office.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Rotorcraft Certification

Office.

(f) 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 helicopter

to a location where the requirements of this

AD can be accomplished.

(g) This amendment becomes effective on

May 26, 1995.

Issued in Fort Worth, Texas, on May 4,

1995.

Mark R. Schilling,

Acting Manager, Rotorcraft Directorate,

Aircraft Certification Service.

[FR Doc. 95–11541 Filed 5–10–95; 8:45 am]

BILLING CODE 4910–13–P

14 CFR Part 39

[Docket No. 95–SW–03–AD; Amendment

39–9225; AD 95–10–08]

Airworthiness Directives; Bell

Helicopter Textron, Inc.-Manufactured

Restricted Category Model UH–1A,

UH–1B, UH–1E, UH–1F, UH–1H, UH–1L,

UH–1P, TH–1F, and TH–1L Helicopters

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule; request for

comments.

SUMMARY: This amendment adopts a

new airworthiness directive (AD) that is

applicable to Bell Helicopter Textron,

Inc. (BHTI)-manufactured restricted

category Model UH–1A, UH–1B, UH–

1E, UH–1F, UH–1H, UH–1L, UH–1P,

TH–1F, and TH–1L helicopters. This

action requires verification that the tail

rotor control system is rigged in

accordance with the applicable

maintenance manual; a fluorescent

penetrant inspection for cracks at the

roots of the gear teeth on the pinion and

gear of affected 42-degree tail rotor drive

gearbox assemblies (42-degree

gearboxes), and replacement of the 42-

degree gearbox pinion or gear if cracks

are found; and, creation of a component

history card to track numbers of torque

events. A torque event is defined as a

takeoff or a lift (internal or external).

This amendment is prompted by 14

accidents reported since 1979 in the

United States and Canada related to

failure of the 42-degree gearbox. The

actions specified in this AD are

intended to prevent failure of the 42-

degree gearbox, loss of tail rotor control,

and subsequent loss of control of the

helicopter.

DATES: Effective May 26, 1995.

Comments for inclusion in the Rules

Docket must be received on or before

July 10, 1995.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Office of the

Assistant Chief Counsel, Attention:

Rules Docket No. 95–SW–03–AD, 2601

Meacham Blvd., Room 663, Fort Worth,

Texas 76137.

FOR FURTHER INFORMATION CONTACT: Mr.

Uday Garadi, Aerospace Engineer, FAA,

Rotorcraft Directorate, Rotorcraft

Certification Office, 2601 Meacham

Blvd., Fort Worth, Texas 76137,

telephone (817) 222–5157, fax (817)

222–5959.

SUPPLEMENTARY INFORMATION: This

amendment adopts a new AD that is

applicable to BHTI-manufactured

restricted category Model UH–1A, UH–

1B, UH–1E, UH–1F, UH–1H, UH–1L,

UH–1P, TH–1F, and TH–1L helicopters.

There have been 14 accidents reported

since 1979 in the United States and

Canada, with the most recent accident

occurring on August 31, 1994, related to

failure of the 42-degree gearbox. In

operation, these helicopters endure

many more torque events than were

originally anticipated during the

certification and fatigue-life

substantiation processes. This was

confirmed by BHTI after bench test

results indicated that gear life is

reduced when the helicopter is

subjected to repeated torque events.

Obviously, operations at power and load

levels outside the gross weight and/or

external cargo hook weight limits

specified in the flight manual (i.e.,

operations at power and load levels in

excess of those allowed by the operating

limitations) will accelerate drivetrain

and/or structural component failure.

The National Transportation Safety

Board (NTSB) has investigated these

accidents and issued a recommendation

that operators should not exceed the

limitations stated in the rotorcraft flight

manual. Obviously, the FAA concurs

with this recommendation. The 42-

degree gearbox is an integral part of the

tail rotor drivetrain. Failure of the 42-

degree gearbox could lead to a complete

loss of directional control. Due to the

criticality of the drivetrain and

structural components in maintaining

control of the helicopter, and the short

compliance time required, this AD is

being issued immediately to correct an

unsafe condition. This condition, if not

corrected, could result in failure of the

42-degree gearbox, loss of tail rotor

control, and subsequent loss of control

of the helicopter.

Since an unsafe condition has been

identified that is likely to exist or

develop on other BHTI-manufactured

restricted category Model UH–1A, UH–

1B, UH–1E, UH–1F, UH–1H, UH–1L,

UH–1P, TH–1F, and TH–1L helicopters

of the same type design, this AD is being

issued to prevent failure of the 42-

degree gearbox, loss of tail rotor control,

and subsequent loss of control of the

helicopter. This AD requires, before

further flight, and thereafter, at intervals

not to exceed 400 torque events,

disassembly of the affected 42-degree

gearbox, part number (P/N) 204–040–

003–023 or –037, a fluorescent

penetrant inspection for cracks at the

roots of the gear teeth on the pinion, P/

N 204–040–500–007 or –009, and gear,

P/N 204–040–500–008 or –010, and

replacement of any unairworthy pinions

or gears as necessary. This AD also

requires creation of a component history

card to track the number of torque

events.

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 Invited

Although this action is in the form of

a final rule that involves requirements

affecting flight safety and, thus, was not
Federal Register / Vol. 60, No. 91 / Thursday, May 11, 1995 / Rules and Regulations 25125

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 No. 95–SW–03–AD.’’ The

postcard will be date stamped and

returned to the commenter.

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.

The FAA has determined that this

regulation is an emergency regulation

that must be issued immediately to

correct an unsafe condition in aircraft,

and that it 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, 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. App. 1354(a), 1421

and 1423; 49 U.S.C. 106(g); and 14 CFR

11.89.

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding a new airworthiness directive to

read as follows:

95–10–08 CALIFORNIA DEPARTMENT OF

FORESTRY; ERICKSON AIR-CRANE

CO.; GARLICK HELICOPTERS;

HAWKINS AND POWERS AVIATION,

INC.; INTERNATIONAL HELICOPTERS,

INC.; SMITH HELICOPTERS;

SOUTHWEST FLORIDA AVIATION;

WEST COAST FABRICATIONS;

WESTERN INTERNATIONAL

AVIATION, INC.; WILLIAMS

HELICOPTER TECHNOLOGY, INC.;

AND, UNC HELICOPTERS: Amendment

39–9225. Docket No. 95–SW–03–AD.

Applicability: Model UH–1A, UH–1B, UH–

1E, UH–1F, UH–1H, UH–1L, UH–1P, TH–1F,

and TH–1L helicopters, with a 42-degree tail

rotor drive gearbox assembly (42-degree

gearbox), part number (P/N) 204–040–003–

023, or –037, installed, certificated in the

restricted category.

Note 1: This AD applies to each helicopter

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

helicopters that have been modified, altered,

or repaired so that the performance of the

requirements of this AD is affected, the

owner/operator must use the authority

provided in paragraph (e) to request approval

from the FAA. This approval may address

either no action, if the current configuration

eliminates the unsafe condition, or different

actions necessary to address the unsafe

condition described in this AD. Such a

request should include an assessment of the

effect of the changed configuration on the

unsafe condition addressed by this AD. In no

case does the presence of any modification,

alteration, or repair remove any helicopter

from the applicability of this AD.

Compliance: Required as indicated, unless

accomplished previously.

To prevent failure of the 42-degree gearbox,

loss of tail rotor control, and subsequent loss

of control of the helicopter, accomplish the

following:

(a) Before further flight, after the effective

date of this AD, verify that the tail rotor

control system is rigged in accordance with

the applicable maintenance manual.

(b) Before further flight, and thereafter at

intervals not to exceed 400 torque events,

disassemble the affected 42-degree gearbox

and inspect for cracks at the roots of the gear

teeth on the pinion, P/N 204–040–500–007 or

–009, and gear, P/N 204–040–500–008 or

–010, using a fluorescent penetrant

inspection method in accordance with the

applicable maintenance manual. Only post

emulsified fluorescent penetrant inspection

materials (Type I, Method B or D, Sensitivity

Level 3 or greater) are approved for use. A

torque event is defined as a takeoff or a lift

(internal or external).

(c) If any crack is found at the roots of the

gear teeth on the pinion or gear, replace the

pinion or gear with an airworthy pinion or

gear in accordance with the applicable

maintenance manual.

(d) Create a component history card for the

42-degree gearbox. Record the number of

torque events on a daily basis.

(e) An alternative method of compliance or

adjustment of the compliance time that

provides an acceptable level of safety may be

used when approved by the Manager,

Rotorcraft Certification Office, FAA,

Rotorcraft Directorate. Operators shall submit

their requests through an FAA Principal

Maintenance Inspector, who may concur or

comment and then send it to the Manager,

Rotorcraft Certification Office.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Rotorcraft Certification

Office.

(f) 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 helicopter

to a location where the requirements of this

AD can be accomplished.

(g) This amendment becomes effective on

May 26, 1995.

Issued in Fort Worth, Texas, on May 4,

1995.

Mark R. Schilling,

Acting Manager, Rotorcraft Directorate,

Aircraft Certification Service.

[FR Doc. 95–11540 Filed 5–10–95; 8:45 am]

BILLING CODE 4910–13–P

14 CFR Part 97

[Docket No. 28214; Amdt. No. 1662]

Standard Instrument Approach

Procedures; Miscellaneous

Amendments

AGENCY: Federal Aviation

Administration (FAA), DOT.

ACTION: Final rule.