25696 Federal Register / Vol. 65, No. 86 / Wednesday, May 3, 2000 / Proposed Rules

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000–NM–98–AD]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 747 Series Airplanes Equipped

With Pratt & Whitney (PW) JT9D–7Q

and JT9D–7Q3 Turbofan Engines

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 Boeing Model 747 series

airplanes. This proposal would require

a detailed visual inspection to detect

evidence of wear or contact between the

precooler support fitting and link

assembly; and rework and

reidentification of the fitting. This

proposal is prompted by a report of

rupturing of a diffuser case on a PW

JT9D–7Q engine due to cracking in the

outer pressure wall in the rear skirt area.

The actions specified by the proposed

AD are intended to prevent contact

between the precooler support link and

the precooler support fitting, which

could contribute to an uncontained

failure of the diffuser case and damage

to the airplane.

DATES: Comments must be received by

June 19, 2000.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 2000–NM–

98–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

Boeing Commercial Airplane Group,

P.O. Box 3707, Seattle, Washington

98124–2207. This information may be

examined at the FAA, Transport

Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Dionne Krebs, Aerospace Engineer,

Propulsion Branch, ANM–140S, FAA,

Transport Airplane Directorate, 1601

Lind Avenue, SW., Renton, Washington

98055–4056; telephone (425) 227–2250;

fax (425) 227–1181.

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 2000–NM–98–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.

2000–NM–98–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

In January 1997, the diffuser case on

a Pratt & Whitney (PW) JT9D–7Q engine

ruptured when the engine was at takeoff

power at the beginning of a takeoff roll.

The engine was installed on a Boeing

Model 747–251 airplane. Both engine

side cowl doors, a precooler, and other

hardware were ejected from the engine

as a result of the rupture of the diffuser

case. The escaping gas and engine

debris blew out the engine pylon access

panels and created holes, cracks, and

other damage to the leading edge,

aileron, and flaps of the wing.

The diffuser case fracture was due to

a crack that most likely developed in a

toolmark that was left by a blending

operation adjacent to the dog-boneshaped embossment at the 11 o’clock

circumferential location of the outer

pressure wall of the case in the area of

the rear skirt. Although extensive

investigation of the incident could not

determine the source of the vibration

that caused the crack to progress in a

high-cycle fatigue mode, the

investigation did reveal evidence of

contact between the precooler support

link and the precooler support fitting.

Contact between the precooler

support link and the precooler support

fitting may result in additional vibration

through the mount boss to the case. The

additional vibration caused by contact

of the support link and the support

fitting may have contributed to

propagation of the crack. Such contact

between the precooler support link and

precooler support fitting, if not

corrected, could contribute to an

uncontained failure of the diffuser case

and damage to the airplane.

Explanation of Relevant Service

Information

Boeing has issued Service Letter 747–

SL–36–089, dated August 10, 1998,

which describes procedures for

reworking certain precooler support

fittings. Accomplishment of the action

specified in the service letter is

intended to adequately address the

identified unsafe condition.

Explanation of Requirements of

Proposed Rule

Since an unsafe condition has been

identified that is likely to exist or

develop on other products of this same

type design, the proposed AD would

require a detailed visual inspection to

detect evidence of wear or contact

between the precooler support fitting

and link assembly; and rework and

reidentification of the fitting. The

rework would be required to be

accomplished in accordance with the

service letter described previously.

Cost Impact

There are approximately 79 airplanes

of the affected design in the worldwide

fleet. The FAA estimates that 27

airplanes of U.S. registry would be

affected by this proposed AD.

It would take approximately 2 work

hours per airplane to accomplish the

proposed inspection, and that the

average labor rate is $60 per work hour.

Based on these figures, the cost impact

of the proposed inspection on U.S.

operators is estimated to be $3,240, or

$120 per airplane.

It would take approximately 16 work

hours per airplane to accomplish the

proposed rework, and that the average

labor rate is $60 per work hour. No parts

are required to accomplish the rework.

Based on these figures, the cost impact

of the proposed rework on U.S.

Federal Register / Vol. 65, No. 86 / Wednesday, May 3, 2000 / Proposed Rules 25697

operators is estimated to be $25,920, or

$960 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 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 the following new airworthiness

directive:

Boeing: Docket 2000–NM–98–AD.

Applicability: Model 747 airplanes,

certificated in any category; equipped with

Pratt & Whitney JT9D–7Q and JT9D–7Q3

turbofan engines.

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 contact between the precooler

support link and the precooler support

fitting, which could contribute to an

uncontained failure of the diffuser case and

damage to the airplane, accomplish the

following:

(a) For any precooler support fitting having

P/N 65B90924–1 or P/N 65B90924–600 that

has not been reworked to the dimensions

specified in Boeing Service Letter 747–SL–

36–089, dated August 10, 1998: Within 6,000

hours time-in-service after the effective date

of this AD, or within 18 months after the

effective date of this AD, whichever occurs

first, perform a detailed visual inspection to

detect evidence of contact wear or contact

between the precooler support fitting and

link assembly, P/N 69B93162–1 or

69B93162–3, in accordance with the service

letter.

(1) If no evidence of contact wear or

contact between the precooler support fitting

and link assembly is found: At the next

engine removal, rework the precooler support

fitting to the dimensions specified in the

service letter, in accordance with the service

letter; and permanently and legibly reidentify

the support fitting as P/N 65B09024–601.

(2) If any evidence of contact wear or

contact between the precooler support fitting

and link assembly is found: Prior to further

flight, rework the precooler support fitting to

the dimensions specified in the service letter,

in accordance with the service letter; and

permanently and legibly reidentify the

support fitting as P/N 65B09024–601.

Note 2: For the purposes of this AD, a

detailed visual inspection is defined as: ‘‘An

intensive visual examination of a specific

structural area, system, installation, or

assembly to detect damage, failure, or

irregularity. Available lighting is normally

supplemented with a direct source of good

lighting at intensity deemed appropriate by

the inspector. Inspection aids such as mirror,

magnifying lenses, etc., may be used. Surface

cleaning and elaborate access procedures

may be required.’’

(b) For any precooler support fitting having

P/N 65B90924–1 or P/N 65B90924–600 that

has been reworked to the dimensions

specified in Boeing Service Letter 747–SL–

36–089, dated August 10, 1998, but has not

been permanently and legibly reidentified:

Within 6,000 hours time-in-service or 18

months after the effective date of this AD,

whichever occurs first, permanently and

legibly reidentify the reworked fitting as P/

N 65B09024–601.

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, Seattle

Aircraft Certification Office (ACO), FAA,

Transport Airplane Directorate. Operators

shall submit their requests through an

appropriate FAA Principal Maintenance

Inspector, who may add comments and then

send it to the Manager, Seattle ACO.

Note 3: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Seattle ACO.

Special Flight Permit

(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 airplane to a

location where the requirements of this AD

can be accomplished.

Issued in Renton, Washington, on April 27,

2000.

Donald L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–11064 Filed 5–2–00; 8:45 am]

BILLING CODE 4910–13–P

FEDERAL COMMUNICATIONS

COMMISSION

47 CFR Part 73

[DA 00–849, MM Docket No. 00–66, RM–

9842]

Radio Broadcasting Services; Des

Moines, NM

AGENCY: Federal Communications

Commission.

ACTION: Proposed rule.

SUMMARY: The Commission requests

comments on a petition filed by Sierra

Grande Broadcasting seeking the

allotment of Channel 287C to Des

Moines, NM, as the community’s first

local aural service. Petitioner is

requested to provide demographic

information showing that Des Moines

qualifies as a ‘‘community’’ for

allotment purposes. Channel 287C can

be allotted to Des Moines in compliance

with the Commission’s minimum

distance separation requirements

without the imposition of a site

restriction, at coordinates 36–45–48 NL;

103–50–12 WL.

DATES: Comments must be filed on or

before June 5, 2000, and reply

comments on or before June 20, 2000.

ADDRESSES: Federal Communications

Commission, 445 12th Street, S.W.,

Room TW-A325, Washington, DC

20554. In addition to filing comments

with the FCC, interested parties should