6494 Federal Register / Vol. 66, No. 14 / Monday, January 22, 2001 / Proposed Rules

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99–SW–27–AD]

Airworthiness Directives; Bell

Helicopter Textron, Inc. Model 412

Helicopters and Agusta S.p.A. Model

AB412 Helicopters

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

supersedure of an existing airworthiness

directive (AD) that applies to certain

serial-numbered Bell Helicopter

Textron, Inc. (Bell) Model 412

helicopters and Agusta S.p.A. (Agusta)

Model AB412 helicopters. That AD

currently requires a temporary

reduction of the never-exceed velocity

(Vne) limitation until an inspection of

the tail rotor yoke (yoke) assembly for

fatigue damage and installation of a

redesigned yoke flapping stop are

accomplished. Recurring periodic and

special inspections to detect

occurrences of yoke overload are also

required. This AD would require the

same actions as the previous AD but

would expand the applicability of the

AD to all Bell Model 412, 412CF, 412EP,

and Agusta Model AB412 helicopters.

This proposal is prompted by the

determination that the unsafe condition

exists on all Bell Model 412 and all

Agusta Model AB412 helicopters,

regardless of serial number. The actions

specified by the proposed AD are

intended to prevent static and dynamic

overload damage to the yoke that could

result in loss of the tail rotor and

subsequent loss of control of the

helicopter.

DATES: Comments must be received on

or before March 23, 2001.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Office of the

Regional Counsel, Southwest Region,

Attention: Rules Docket No. 99–SW–27–

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.

The service information referenced in

the proposed AD may be obtained from

Bell Helicopter Textron, Inc., P.O. Box

482, Fort Worth, Texas 76101, telephone

(817) 280–3391, fax (817) 280–6466 for

the Bell Model 412 helicopters; and

Agusta S.p.A., 21017 Cascina Costa di

Samarate (VA), Italy, Via Giovanni

Agusta 520, telephone 39 (0331) 229111,

fax 39 (0331) 229605–222595 for the

Agusta Model AB412 helicopters. This

information may be examined at the

FAA, Office of the Regional Counsel,

Southwest Region, 2601 Meacham

Blvd., Room 663, Fort Worth, Texas.

FOR FURTHER INFORMATION CONTACT:

Uday Garadi, Aviation Safety Engineer,

FAA, Rotorcraft Directorate, Rotorcraft

Standards Staff, 2601 Meacham Blvd.,

Fort Worth, Texas 76137, telephone

(817) 222–5123, fax (817) 222–5961.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to

participate in the maksing 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, specified

above, 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. 99–SW–27–

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. 99–SW–27–AD, 2601

Meacham Blvd., Room 663, Fort Worth,

Texas 76137.

Discussion

On March 16, 1998, the FAA issued

AD 98–07–03, Amendment 39–10421,

Docket No. 97–SW–58–AD (63 FR

14026, March 24, 1998), applicable to

Bell Model 412 helicopters, serial

numbers (S/N) 33001 through 33213,

34001 through 34024, 36001 through

36121, 46400 through 46434, and 46437;

and Agusta Model AB412 helicopters,

S/N prior to and including S/N 25806

and S/N 25901, to require a temporary

reduction of the Vne limitation until an

inspection of the yoke assembly for

fatigue damage and installation of a

redesigned yoke flapping stop are

accomplished. Recurring periodic and

special inspections to detect

occurrences of yoke overload are also

required. That action was prompted by

laboratory tests and engineering

analyses which indicated that the yoke

assembly is susceptible to fatigue

damage due to unforeseen static and

dynamic loading of the tail rotor against

the original flapping stop. The

requirements of that AD are intended to

prevent fatigue failure of the yoke that

could result in loss of control of the tail

rotor and subsequent loss of control of

the helicopter. A correction to a

technical bulletin date referenced in

that AD was issued on July 10, 1998 (63

FR 38742, July 20, 1998).

Since the issuance of AD 98–07–03,

the FAA has determined that the unsafe

condition exists on all Bell Model 412,

412CF, and 412 EP and Agusta Model

AB412 helicopters and that the

applicability of AD 98–07–03 should

have included all serial numbers of

these helicopters. The proposed AD

would also correct the unsafe condition,

which was listed as fatigue failure and

correct the reference to Registro

Aeronautico Italiano AD 97–223, which

was dated incorrectly in AD 98–07–03.

Since an unsafe condition has been

identified that is likely to exist or

develop on all Bell Model 412 or Agusta

Model AB412 helicopters of the same

type designs, the proposed AD would

supersede AD 98–07–03. The proposed

AD would require a reduction of the

Vne limitation until an inspection of the

yoke assembly for static and dynamic

overload damage and installation of a

redesigned yoke flapping stop are

accomplished and includes additional

periodic and special inspections to

detect a yoke overload.

The FAA estimates that 135

helicopters of U.S. registry would be

affected by this proposed AD, that it

would take approximately 6.5 work

hours per helicopter to install the

placard, inspect the yoke assembly, and

install the yoke. Required parts would

Federal Register / Vol. 66, No. 14 / Monday, January 22, 2001 / Proposed Rules 6495

cost approximately $511 per helicopter.

Based on these figures, the total cost

impact of the proposed AD on U.S.

operators is estimated to be $121,635.

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

removing Amendment 39–10421 (63 FR

14026, March 24, 1998 and 63 FR

38742, July 20, 1998), and by adding a

new airworthiness directive (AD), to

read as follows:

Bell Helicopter Textron, Inc. and Agusta

S.p.A.: Docket No. 99–SW–27–AD.

Supersedes AD 98–07–03, Amendment 39–

10421, Docket No. 97–SW–58–AD.

Applicability: Bell Helicopter Textron, Inc.

Model 412, 412CF, and 412EP helicopters

and Agusta S.p.A. Model AB412 helicopters,

with tail rotor yoke assembly, part number

(P/N) 212–011–702–all dash numbers,

installed, 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

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 (e) 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 static and dynamic overload

damage to the tail rotor yoke (yoke) that

could result in loss of the tail rotor and

subsequent loss of control of the helicopter,

accomplish the following:

(a) Before further flight, review the

historical records of the yoke assembly for

any static or dynamic overload damage

history, other than normal usage, that could

have imposed a bending load on the yoke but

did not require replacing the yoke assembly;

for example, an incident in which a damaged

tail rotor blade was replaced due to a blade

strike. If such a history exists, replace the

yoke with an airworthy yoke.

(b) Before further flight, unless the

requirements of paragraph (c) of this AD have

been accomplished previously:

(1) Install a Never Exceed Velocity (Vne)

red line at 120 knots indicated airspeed

(KIAS) on the pilot and copilot airspeed

indicators using red tape or paint and a

slippage indicator on the instrument case and

glass.

(2) Install a placard made of material that

is not easily erased, disfigured, or obscured

on the instrument panel in clear view of the

pilot and copilot: ‘‘Observe temporary

Maximum Never Exceed (Vne) airspeed red

line (marked at 120 knots indicated airspeed

(KIAS)). Vne is 20 KIAS less than the value

presented on the airspeed limitation placard

for each ambient condition.’’

(3) Insert the applicable Bell Helicopter

Textron (BHT) 412 Temporary Revision,

dated August 16, 1996, into the Model 412

Rotorcraft Flight Manual (RFM) or the

applicable section of Agusta AB412

Temporary Revision No. 2, dated April 17,

1997, into the Model AB412 RFM.

(c) Within 180 calendar days:

(1) Remove yoke assembly, P/N 212–011–

702-all dash numbers, and replace it with an

airworthy yoke assembly, P/N 212–011–702-

all dash numbers, with zero hours time-inservice (TIS), or an airworthy yoke

(regardless of TIS) that has passed a one-time

x-ray diffraction inspection in accordance

with BHT Alert Service Bulletin (ASB) 412–

96–89, Revision A, dated October 17, 1997;

BHT ASB 412CF–96–01, dated September 3,

1996; or, Agusta Bolletino Tecnico

(Technical Bulletin) No. 412–65, dated April

17, 1997, whichever is applicable.

(2) Install an airworthy tail rotor flapping

stop, P/N 212–011–713–103.

(3) After the requirements of paragraphs

(c)(1) and (c)(2) of this AD are accomplished,

remove the 120 KIAS redline from the pilot

and copilot airspeed indicators; remove the

Vne airspeed restriction placard; and remove

the BHT 412 Temporary Revision, dated

August 16, 1996; BHT ASB 412CF–96–01,

dated September 3, 1996; or Agusta AB412

Temporary Revision No. 2, as applicable,

from the RFM.

(d) After accomplishing the requirements

of paragraph (c) of this AD, at intervals not

to exceed 25 hours TIS, inspect the yoke

assembly and tail rotor flapping stop (stop)

in accordance with Part III, Recurring 25-

Hour Special Inspection and Conditional

Inspection Requirement, of Bell Helicopter

Textron ASB 412–96–89, Revision A, dated

October 17, 1997; BHT ASB 412CF–96–01,

dated September 3, 1996; or Agusta Bolletino

Tecnico (Technical Bulletin) No. 412–65,

dated April 17, 1997, as applicable. Replace

any unairworthy yoke assembly or stop with

an airworthy yoke assembly or stop before

further flight.

(e) 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, Regulations

Group, Rotorcraft Directorate, FAA.

Operators shall submit their requests through

an FAA Principal Maintenance Inspector,

who may concur or comment and then send

it to the Manager, Regulations Group.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Regulations Group.

(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

at airspeeds not to exceed 120 KIAS to a

location where the requirements of this AD

can be accomplished.

Note 3: The subject of this AD is addressed

in Registro Aeronautico Italiano (Italy) AD

97–223, dated August 1, 1997.

Issued in Fort Worth, Texas, on January 8,

2001.

Henry A. Armstrong,

Manager, Rotorcraft Directorate, Aircraft

Certification Service.

[FR Doc. 01–1587 Filed 1–19–01; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000–NM–272–AD]

RIN 2120–AA64

Airworthiness Directives; Bombardier

Model DHC–7 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

adoption of a new airworthiness