This section of the FEDERAL REGISTER

contains notices to the public of the proposed

issuance of rules and regulations. The

purpose of these notices is to give interested

persons an opportunity to participate in the

rule making prior to the adoption of the final

rules.

Proposed Rules Federal Register

24136

Vol. 63, No. 84

Friday, May 1, 1998

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98–NM–113–AD]

RIN 2120–AA64

Airworthiness Directives; British

Aerospace BAe Model ATP Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

adoption of a new airworthiness

directive (AD) that is applicable to

certain British Aerospace BAe Model

ATP airplanes. This proposal would

require repetitive inspections for

discrepancies of the spring strut

assembly of the forward door of the

main landing gear (MLG), and

replacement of the existing spring strut

assembly with a new or serviceable part,

if necessary. This proposal also would

require eventual replacement of the

existing spring strut assembly with an

improved part, which, when

accomplished, would terminate the

repetitive inspections. This proposal is

prompted by issuance of mandatory

continuing airworthiness information by

a foreign civil airworthiness authority.

The actions specified by the proposed

AD are intended to prevent failure of the

spring strut assembly of the forward

door of the MLG, which, if not

corrected, could result in inability to

extend the MLG.

DATES: Comments must be received by

June 1, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 98–NM–

113–AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056.

Comments may be inspected at this

location between 9:00 a.m. and 3:00

p.m., Monday through Friday, except

Federal holidays.

The service information referenced in

the proposed rule may be obtained from

AI(R) American Support, Inc., 13850

Mclearen Road, Herndon, Virginia

20171. This information may be

examined at the FAA, Transport

Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Norman B. Martenson, Manager,

International Branch, ANM–116, FAA,

Transport Airplane Directorate, 1601

Lind Avenue, SW., Renton, Washington

98055–4056; telephone (425) 227–2110;

fax (425) 227–1149.

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 shall

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 notice 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 comments

submitted in response to this notice

must submit a self-addressed, stamped

postcard on which the following

statement is made: ‘‘Comments to

Docket Number 98–NM–113–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, Transport Airplane Directorate,

ANM–114, Attention: Rules Docket No.

98–NM–113–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

The Civil Aviation Authority (CAA),

which is the airworthiness authority for

the United Kingdom, notified the FAA

that an unsafe condition may exist on

certain British Aerospace BAe Model

ATP airplanes. The CAA advises that a

BAe Model ATP airplane made an

emergency landing because the left

main landing gear (MLG) failed to

extend. Investigation of the incident

revealed a number of possible causes,

including corrosion, wear, or damage to

the operating mechanism. On March 31,

1998, the FAA issued a notice of

proposed rulemaking (NPRM) to address

these possible causes (reference Docket

No. 97–NM–312–AD; 63 FR 16713,

April 6, 1998).

Further investigation of the incident

revealed that the spring strut assembly

of the forward door of the MLG on the

airplane was loose. (The spring strut

assembly is part of the mechanism

which opens the MLG door and allows

extension and retraction of the MLG.)

Similar loose attachment also was

observed on one other in-service

airplane, and has been attributed to

damage of the rivets that connect the

fork end of the spring strut assembly to

the tube of the assembly. Failure of

these rivets, if not corrected, could

cause failure of the spring strut

assembly of the forward door of the

MLG, which could result in inability to

extend the MLG.

Explanation of Relevant Service

Information

The manufacturer has issued British

Aerospace Alert Service Bulletin ATP–

32–85, Revision 1, dated March 20,

1998, which describes procedures for

repetitive visual inspections for

discrepancies of the fork end of the

spring strut assembly of the forward

door of the left and right MLG on the

airplane. The actions involve inspecting

for looseness or damage of the rivets

that connect the fork end fitting to the

tube of the spring strut assembly, and

inspecting for movement between the

fork end fitting and the tube of the

spring strut assembly. This alert service

bulletin also describes procedures for

replacing the spring strut assembly with

a new or serviceable part, if any rivet is

found to be damaged, if any rivet hole

is found to be elongated, or if the
Federal Register / Vol. 63, No. 84 / Friday, May 1, 1998 / Proposed Rules 24137

attachment of the fork end fitting to the

tube is found to be loose. The CAA

classified this alert service bulletin as

mandatory in order to assure the

continued airworthiness of these

airplanes in the United Kingdom.

The manufacturer also has issued

British Aerospace Service Bulletin

ATP–32–87, dated January 29, 1998,

which describes procedures for

replacing the existing spring strut

assembly of the forward door of the

MLG with an improved spring strut

assembly. Such replacement eliminates

the need for the repetitive inspections

described previously.

Accomplishment of the actions

specified in the service bulletins is

intended to adequately address the

identified unsafe condition.

FAA’s Conclusions

This airplane model is manufactured

in the United Kingdom and is type

certificated for operation in the United

States under the provisions of Section

21.29 of the Federal Aviation

Regulations (14 CFR 21.29) and the

applicable bilateral airworthiness

agreement. Pursuant to this bilateral

airworthiness agreement, the CAA has

kept the FAA informed of the situation

described above. The FAA has

examined the findings of the CAA,

reviewed all available information, and

determined that AD action is necessary

for products of this type design that are

certificated for operation in the United

States.

Explanation of Requirements of

Proposed Rule

Since an unsafe condition has been

identified that is likely to exist or

develop on other airplanes of the same

type design registered in the United

States, the proposed AD would require

accomplishment of actions specified in

the service bulletins described

previously, except as discussed below.

Differences Between Proposed Rule and

Service Bulletin

Operators should note that this AD

proposes to mandate the replacement of

the existing spring strut assembly of the

forward door of the MLG with an

improved spring strut assembly, as

described in British Aerospace Service

Bulletin ATP–32–87, dated January 29,

1998, as terminating action for the

repetitive inspections specified in

British Aerospace Alert Service Bulletin

ATP–32–85, Revision 1, dated March

20, 1998. Accomplishment of the

modification specified in this service

bulletin has not been classified as

mandatory by the CAA.

The FAA has determined that, in

certain cases, long-term continued

operational safety will be better assured

by design changes to remove the source

of the problem, rather than by repetitive

inspections. Long-term inspections may

not be providing the degree of safety

assurance necessary for the transport

airplane fleet. This, coupled with a

better understanding of the human

factors associated with numerous

continual inspections, has led the FAA

to consider placing less emphasis on

inspections and more emphasis on

design improvements. The proposed

requirement to replace the existing

spring strut assembly with an improved

spring strut assembly is in consonance

with these conditions.

Cost Impact

The FAA estimates that 10 airplanes

of U.S. registry would be affected by this

proposed AD.

It would take approximately 4 work

hours (2 work hours per MLG) to

accomplish the proposed inspection, at

an average labor rate of $60 per work

hour. Based on this figure, the cost

impact of the inspection proposed by

this AD on U.S. operators is estimated

to be $2,400, or $240 per airplane, per

inspection cycle.

It would take approximately 12 work

hours (6 work hours per MLG) to

accomplish the proposed modification,

at an average labor rate of $60 per work

hour. Required parts would cost

approximately $2,200 per airplane

($1,100 per MLG). Based on this figure,

the cost impact of the modification

proposed by this AD on U.S. operators

is estimated to be $29,200, or $2,920 per

airplane.

The cost impact figures discussed

above are based on assumptions that no

operator has yet accomplished any of

the proposed requirements of this AD

action, and that no operator would

accomplish those actions in the future if

this AD were not adopted.

Regulatory Impact

The regulations proposed herein

would 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

proposal would not have sufficient

federalism implications to warrant the

preparation of a Federalism Assessment.

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 the following new airworthiness

directive:

British Aerospace Regional Aircraft

(Formerly Jetstream Aircraft Limited;

British Aerospace (Commercial Aircraft)

Limited): Docket 98–NM–113–AD.

Applicability: BAe Model ATP airplanes,

as listed in British Aerospace Alert Service

Bulletin ATP–32–85, Revision 1, dated

March 20, 1998, certificated in any category.

Note 1: This AD applies to each airplane

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

airplanes 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 failure of the spring strut

assembly of the forward door of the main

landing gear (MLG), which, if not corrected,

could result in the inability to extend the

MLG, accomplish the following:

(a) Within 600 flight hours after the

effective date of this AD, perform a visual
24138 Federal Register / Vol. 63, No. 84 / Friday, May 1, 1998 / Proposed Rules

inspection for discrepancies of the fork end

of the spring strut assembly of the forward

door of the MLG, on the left and right side

of the airplane; in accordance with British

Aerospace Alert Service Bulletin ATP–32–85,

Revision 1, dated March 20, 1998.

(1) If no discrepancy is detected, repeat the

visual inspection thereafter at intervals not to

exceed 1,500 flight hours until the actions

specified by paragraph (b) of this AD are

accomplished.

(2) If any discrepancy is detected, prior to

further flight, replace the existing spring strut

assembly with a new or serviceable part, in

accordance with the alert service bulletin.

Repeat the visual inspection thereafter at

intervals not to exceed 1,500 flight hours

until the actions specified by paragraph (b)

of this AD are accomplished.

(b) Within 18 months after the effective

date of this AD, replace the spring strut

assembly of the forward door of the MLG

with an improved spring strut assembly, on

the left and right side of the airplane; in

accordance with British Aerospace Service

Bulletin ATP–32–87, dated January 29, 1998.

This replacement constitutes terminating

action for the requirements 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,

International Branch, ANM–116, FAA,

Transport Airplane Directorate. Operators

shall submit their request through an

appropriate FAA Principal Maintenance

Inspector, who may add comments and then

send it to the Manager, International Branch,

ANM–116.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the International Branch,

ANM–116.

(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 airplane to

a location where the requirements of this AD

can be accomplished.

Issued in Renton, Washington, on April 24,

1998.

Gary L. Killion,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 98–11561 Filed 4–30–98; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–ANE–59–AD]

RIN 2120–AA64

Airworthiness Directives; Pratt &

Whitney JT8D Series Turbofan Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

supersedure of an existing airworthiness

directive (AD), applicable to certain

Pratt & Whitney (PW) JT8D series

turbofan engines, that currently requires

initial and repetitive inspections of the

No. 7 fuel nozzle and support assembly,

replacement of the No. 7 fuel nozzle and

support assembly with a more leakresistant configuration, and replacement

of aluminum oil pressure and scavenge

tube fittings with steel fittings. In

addition, the current AD requires

replacing an additional aluminum oil

scavenge line bolt with a steel bolt. This

action would require initial and

repetitive borescope inspections for loss

of fuel nozzle nut torque and nozzle

support wear, and replacement or

modification of the fuel nozzles at the

next accessibility of the diffuser build

group as terminating action to the

inspections. This proposal is prompted

by reports of loss of fuel nozzle nut

torque and nozzle support wear. The

actions specified by the proposed AD

are intended to prevent loss of fuel

nozzle nut torque and nozzle support

wear, which could result in a fuel leak

and possible engine fire.

DATES: Comments must be received by

June 30, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), New England

Region, Office of the Regional Counsel,

Attention: Rules Docket No. 97–ANE–

59–AD, 12 New England Executive Park,

Burlington, MA 01803–5299. Comments

may also be sent via the Internet using

the following address: ‘‘9-adengineprop@faa.dot.gov’’. Comments

sent via the Internet must contain the

docket number in the subject line.

Comments may be inspected at this

location between 8:00 a.m. and 4:30

p.m., Monday through Friday, except

Federal holidays. The service information referenced in

the proposed rule may be obtained from

Pratt & Whitney, 400 Main St., East

Hartford, CT 06108; telephone (860)

565–6600, fax (860) 565–4503. This

information may be examined at the

FAA, New England Region, Office of the

Regional Counsel, 12 New England

Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT:

Christopher Spinney, Aerospace

Engineer, Engine Certification Office,

FAA, Engine and Propeller Directorate,

telephone (781) 238–7175, fax (781)

238–7199.

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, specified

above, will be considered before taking

action on the proposed rule. The

proposals contained in this notice 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 comments

submitted in response to this notice

must submit a self-addressed, stamped

postcard on which the following

statement is made: ‘‘Comments to

Docket Number 97–ANE–59–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, New England Region, Office of the

Regional Counsel, Attention: Rules

Docket No. 97–ANE–59–AD, 12 New

England Executive Park, Burlington, MA

01803–5299.

Discussion

On January 24, 1995, the Federal

Aviation Administration (FAA) issued

airworthiness directive AD 95–02–16,

Amendment 39–9135 (60 FR 6654,

February 3, 1995), applicable to Pratt &

Whitney (PW) JT8D series turbofan

engines, to require inspection of the No.

7 fuel nozzle and support assembly for

evidence of fuel leakage and burning

until replacement of the No. 7 fuel

nozzle and support assembly with an

improved sealing configuration. That

AD also requires replacement of the

aluminum oil tube fittings with steel

fittings. In addition, that AD requires

replacing an additional aluminum oil

scavenge line bolt with a steel bolt. That

action was prompted by reports of two

uncontained engine fires due to fuel

leakage from the No. 7 fuel nozzle and