Federal Register / Vol. 62, No. 180 / Wednesday, September 17, 1997 / Proposed Rules 48799

exceeding established limits and rate

them separately from the rest of the

policyholder population. This concept

is consistent with other private and

public insurance programs which have

the means to identify participants with

high losses and separately rate them for

the risk associated with the losses they

have incurred. In 1997 25,126 NCS

listings appeared on county crop

actuarial documents. This number,

which is less than two percent of the

policyholders with active crop policies

in 1996, includes producers no longer

actively engaged in farming, as well as

duplicate names for those producers

who farm multiple crops or farm in

more than one county. The list does not

include other persons who share in the

crop with a NCS producer, but who are

required to pay the same NCS rates as

the listed producer. The primary benefit

of the NCS program is that by

individually rating high loss producers

under this process, FCIC is able to

exclude their loss histories from the

premium rating formulas. It has been

estimated that on a crop policy basis,

this saves non-NCS producers from five

to nine percent on the cost of their crop

insurance coverage. It has also been

estimated that if NCS were eliminated,

the reintroduction of the loss history

into the rating pool would result in

across the board premium increases for

all non-NCS producers of $50 to $90 per

crop policy annually.

Under the current NCS regulations,

producers are selected for NCS

adjustment if they meet the following

criteria:

(1) Three or more indemnified losses

during the NCS base period, (The base

period generally means ten consecutive

crop years. The base period for 1998

NCS selections is 1987–1996 for most

crops.)

(2) Cumulative indemnities exceed

same period cumulative premiums by at

least $1,000.

(3) A premium has been earned in at

least one of the most recent 4 crop years

in the base period.

(4) The result of dividing the number

of indemnified losses during the base

period by the number of years premium

is earned is equal to, or greater than, .60.

(5) Either of the following apply:

(a) The ‘‘Z’’ score (a reference loss

ratio used to ensure comparability

between producers) equals 2.00 or

greater; or

(b) Five or more indemnified losses

have occurred during the NCS base

period and the cumulative loss ratio

equals 1.50 or greater.

The consecutive occurrence of

widespread adverse weather conditions

in the Upper Midwest and Southwest, at

the same time when changing U.S. farm

policy has increased producer’s reliance

on crop insurance, has resulted in a

greater awareness of the NCS program.

Some producers are concerned that their

recent losses will be followed by

selection for NCS rate or coverage

adjustments. This concern has also been

echoed by producer organizations and

elected representatives. FCIC had

formulated a two tiered strategy to deal

with these concerns. The short-term

plan was to thoroughly review the 1998

NCS selections to ensure that producers

who had been impacted by widespread

disasters were not placed on NCS based

primarily on losses associated with the

disasters. For the longer term, FCIC was

to survey interested parties about NCS

and form a work group to recommend

changes to the NCS program for the

1999 crop year. The survey was

completed and the responses received

reviewed. The work group was not

formed because of concerns relating to

the Federal Advisory Committee Act.

Instead, FCIC has determined to seek

public comment regarding the NCS

process through the Federal Register

and this notice. Comments received in

response to the original survey will be

considered in conjunction with any

comments received in response to this

notice.

Executive Order 12866

The Office of Management and Budget

(OMB) has determined this rule to be

not significant for the purposes of

Executive Order 12866, and, therefore,

this rule has not been reviewed by

OMB.

Signed in Washington, D.C., on September

12, 1997.

Kenneth D. Ackerman,

Manager, Federal Crop Insurance

Corporation.

[FR Doc. 97–24770 Filed 9–16–97; 8:45 am]

BILLING CODE 3410–08–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–ANE–05]

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 Pratt &

Whitney JT8D series turbofan engines,

that currently requires a determination

of the utilization rate and coating type

of the 7th, 8th, 9th, 10th, 11th, and 12th

stage high pressure compressor (HPC)

disks, and removal, inspection for

corrosion, and recoating of those HPC

disks based on utilization rate. This

action would shorten the inspection

interval for certain low utilization disks.

This proposal is prompted by reports of

an additional uncontained 9th stage

HPC disk failure due to corrosion

pitting. The actions specified by the

proposed AD are intended to prevent

fracture of the HPC disks, which can

result in uncontained release of engine

fragments, inflight engine shutdown,

and airframe damage.

DATE: Comments must be received by

November 17, 1997.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), New England

Region, Office of the Assistant Chief

Counsel, Attention: Rules Docket No.

97–ANE–05, 12 New England Executive

Park, Burlington, MA 01803–5299.

Comments may also be sent via the

Internet using the following address: ‘‘9-

ad-engineprop@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

Assistant Chief Counsel, 12 New

England Executive Park, Burlington,

MA.

FOR FURTHER INFORMATION CONTACT:

Christopher Spinney, Aerospace

Engineer, Engine Certification Office,

FAA, Engine and Propeller Directorate,

12 New England Executive Park,

Burlington, MA 01803–5299; 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
48800 Federal Register / Vol. 62, No. 180 / Wednesday, September 17, 1997 / Proposed Rules

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–05.’’ 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

Assistant Chief Counsel, Attention:

Rules Docket No. 97–ANE–05, 12 New

England Executive Park, Burlington, MA

01803–5299.

Discussion

On September 15, 1994, the Federal

Aviation Administration (FAA) issued

airworthiness directive AD 94–20–01,

Amendment 39–9029 (59 FR 49175,

September 27, 1994), applicable to Pratt

& Whitney (PW) JT8D–1, –1A, –1B, –7,

–7A, –7B, –9, –9A, –11, –15, –15A, –17,

–17A, –17R, and –17AR turbofan

engines, to require a record search,

initial and repetitive on-wing and shop

inspections to detect corrosion on high

pressure compressor (HPC) disks, and

removal from service of engines with

HPC disks corroded beyond serviceable

limits. That action was prompted by an

investigation into an uncontained PW

JT8D engine failure caused by severe

corrosion on the 9th stage HPC disk.

That condition, if not corrected, could

result in fracture of the HPC disks,

which can result in uncontained release

of engine fragments, inflight engine

shutdown, and airframe damage.

Since the issuance of that AD, the

FAA has received a report of a Boeing

737–232 powered by JT8D–7B turbofan

engines that experienced an

uncontained 9th stage HPC disk rupture

in December 1995 during takeoff, which

resulted in aircraft damage. The

investigation determined that the 9th

stage HPC disk rim failed due to a

fatigue crack originating from a

corrosion pit on the forward surface of

the rim in the bottom of a compressor

blade dovetail slot, which propagated in

low cycle fatigue, and eventually

fractured the hub. The investigation also

identified extensive corrosion pitting in

multiple sites that were concentrated in

the outer web and rim areas of the disk.

Airworthiness Directive 94–20–01

was published due to a similar

uncontained PW JT8D series 9th stage

HPC disk failure in which corrosion

pitting was a factor. The investigation

into this earlier failure also identified

extensive corrosion on the failed 9th

stage disk as well as the 8th and 10th

stage disks. Corrosion pits as deep as

0.020 inch and 0.060 inch in diameter

were found in some areas of the

ruptured 9th stage HPC disk. This

earlier investigation concluded that PW

JT8D HPC disks are more susceptible to

severe corrosion when operating in a

low utilization profile. Low utilization

operating profiles can induce formation

of condensation within the engine,

thereby promoting corrosion scales and

pits, which adversely affect the disk

fatigue lives. As a compounding

influence, low utilization rates imply

longer on-wing calendar intervals and

less frequent engine shop visits and

module disassembles.

This earlier investigation also

evaluated the effectiveness of the

protective coatings and lubricant/antigallant films used on the PW JT8D HPC

disks. The FAA determined that varying

degrees of corrosion resistance depends

on the type of coating. As a result of this

earlier investigation, the FAA issued AD

94–20–01, requiring a record search of

the service history of the 8th, 9th, and

10th high pressure compressor disks,

initial and repetitive on-wing and shop

inspections to detect corrosion on HPC

disks, and removal from service of

engines with HPC disks corroded

beyond serviceable limits. The

inspection program of AD 94–20–01

accounts for the variability in corrosion

resistance and provides separate

inspection instructions and criteria

depending on the type of protective

coating applied.

This proposed AD would supersede

AD 94–20–01 and require the same

record search and inspection program

but on a more conservative inspection

schedule. The proposed AD would

require the low utilization disks,

regardless of the disk coating, to be

inspected at an interval of 7 years since

new, replated, or corrosion inspected

(YRSNRC) in accordance with the

engine manual. Currently, the

inspection interval for low utilization

disks is based on the disk coating and

the maximum inspection interval ranges

from 9 to 11 YRSNRC depending on the

part number and the type of coating.

The high utilization disk inspection

interval remains unchanged.

The FAA has reviewed and approved

the technical contents of PW Alert

Service Bulletin (ASB) No. 6038,

Revision 5, dated August 17, 1994, that

describes on-wing and shop inspections

to detect corrosion on HPC disks, and

removal from service of HPC disks

corroded beyond serviceable limits.

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

supersede AD 94–20–01 to shorten the

inspection interval for certain low

utilization disks.

There are approximately 11,119

engines of the affected design in the

worldwide fleet. The FAA estimated

that 6,815 engines installed on aircraft

of U.S. registry were affected by AD 94–

20–01, and 2 work hours would be

necessary to determine the utilization

rate and type of surface treatment. Based

on domestic fleet-wide data, the FAA

estimated that approximately 8.7% or

593 engines were considered to have

low utilization rates. Approximately 8.6

work hours would be required to

remove these engines from the aircraft,

500 work hours to tear down, deblade,

and to reassemble the engine, and 8.6

work hours to reinstall the reassembled

engines. The FAA estimated 69% of the

removed engines would require

scrapping the disks. The FAA assumed

that three disks per engine may require

replacement, and the cost of a new disk

would be approximately $7,000. The

average labor rate is $60 per work hour.

Based on these figures, the total cost

impact of AD 94–20–01 on U.S.

operators was estimated to be

$14,279,542. The cost increase between

AD 94–20–01 and this proposed AD is

based on the increased inspections of

some low utilization disks. The FAA

estimates 31% of the low utilization

disks would require an additional

inspection. The cost of these additional

inspections is estimated to be

$4,426,658.

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
Federal Register / Vol. 62, No. 180 / Wednesday, September 17, 1997 / Proposed Rules 48801

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

removing amendment 39–9029 (59 FR

49175, September 27, 1994) and by

adding a new airworthiness directive to

read as follows:

Pratt & Whitney: Docket No. 97–ANE–05.

Supersedes AD 94–20–01, Amendment

39–9029.

Applicability: Pratt & Whitney (PW) JT8D–

1, –1A, –1B, –7, –7A, –7B, –9, –9A, –11, –15,

–15A, –17, –17A, –17R, and –17AR turbofan

engines installed on but not limited to Boeing

737 and 727 series, and McDonnell Douglas

DC–9 series aircraft.

Note 1: This airworthiness directive (AD)

applies to each engine 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 engines 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 (i)

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 fracture of the high pressure

compressor (HPC) disks, which can result in

uncontained release of engine fragments,

inflight engine shutdown, and airframe

damage, accomplish the following:

(a) Within four months of the effective date

of this AD, determine the fleet and sub-fleet

average engine utilization rate for the 12

months of operations prior to August 17,

1994, the issue date of PW Alert Service

Bulletin (ASB) No. 6038, Revision 5, in

accordance with paragraph 2.A of PW ASB

No. 6038, Revision 5, dated August 17, 1994.

(1) For fleet or sub-fleet average utilization

rates that are equal to or greater than 1,300

hours per year, and equal to or greater than

900 cycles per year, perform the following:

(i) For engines or stage 7 through stage 12

HPC disks that were added to a fleet or

subfleet after November 28,1994, and that

were previously designated as low utilization

disks in accordance with PW ASB No. 6038,

Revision 5, dated August 17, 1994, comply

with the requirements of paragraph (d) of this

AD.

(ii) Designate all other stage 7 through stage

12 HPC disks as high utilization disks and

comply with the requirements of paragraph

(b) of this AD.

(2) For fleet or sub-fleet average utilization

rates that are less than 1,300 hours per year

or less than 900 cycles per year, within four

months after the effective date of this AD,

determine the utilization rate for each stage

7 through stage 12 HPC disk in accordance

with paragraph 2.B.(1) of PW ASB No. 6038,

Revision 5, dated August 17, 1994.

(i) For each stage 7 through stage 12 HPC

disk with an initial utilization rate equal to

or greater than 1,300 hours per year, and

equal to or greater than 900 cycles per year,

designate this disk as a high utilization disk

and inspect in accordance with paragraph (c)

of this AD.

(ii) For each stage 7 through stage 12 HPC

disk with an initial utilization rate less than

1,300 hours per year or less than 900 cycles

per year, designate this disk as a low

utilization disk and inspect in accordance

with paragraph (d) of this AD.

(iii) For each stage 7 through stage 12 HPC

disk with an unknown initial utilization rate,

designate this disk as a low utilization disk

and inspect in accordance with paragraph (d)

of this AD.

Note 2: Once a disk is designated as low

utilization, then it must retain this

designation for the life of the disk or until

recoated.

(iv) For recoated or new disks, designate

this disk as a high utilization disk and

inspect in accordance with paragraph (c) of

this AD.

(b) For high average utilization fleets and

sub-fleets, excluding those disks identified in

paragraph (a)(1)(i) of this AD, perform the

following for each stage 7 through stage 12

HPC disk in that fleet or sub-fleet:

(1) Inspect, and recoat or replace if

necessary, at the next part accessibility of the

disk, in accordance with paragraph 2.D.(1)(b)

and Chart A of PW ASB No. 6038, Revision

5, dated August 17, 1994.

(2) Recalculate the fleet or sub-fleet average

utilization rate at 12 month intervals after the

previous date of utilization determination in

accordance with paragraph 2.B of PW ASB

No. 6038, Revision 5, dated August 17, 1994.

(i) For fleet or sub-fleet average utilization

rates that are equal to or greater than 1,300

hours per year, and equal to or greater than

900 cycles per year, continue to designate all

stage 7 through stage 12 HPC disks as high

utilization disks and comply with the

requirements of paragraph (b) of this AD.

(ii) For fleet or sub-fleet average utilization

rates that are less than 1,300 hours per year

or less than 900 cycles per year, within four

months of compliance with paragraph (b)(2)

of this AD, determine the utilization rate for

each stage 7 through stage 12 HPC disk in

accordance with paragraph 2.B.(1) of PW

ASB No. 6038, Revision 5, dated August 17,

1994, as follows:

(A) For each stage 7 through stage 12 HPC

disk with a utilization rate equal to or greater

than 1,300 hours per year, and equal to or

greater than 900 cycles per year, designate

this disk as a high utilization disk and

inspect in accordance with paragraph (c) of

this AD.

(B) For each stage 7 through stage 12 HPC

disk with a utilization rate less than 1,300

hours per year or less than 900 cycles per

year, designate this disk as a low utilization

disk and inspect in accordance with

paragraph (d) of this AD.

(C) For each stage 7 through stage 12 HPC

disk with an unknown utilization rate,

designate this disk as a low utilization disk

and inspect in accordance with paragraph (d)

of this AD.

Note 3: Once a disk is designated as low

utilization, then it must retain this

designation for the life of the disk or until

recoated.

(c) For high utilization stage 7 through

stage 12 HPC disks, perform the following:

(1) Inspect, and recoat or replace if

necessary, at the next part accessibility of the

disk, in accordance with paragraph 2.D.(1)(b)

and Chart A of PW ASB No. 6038, Revision

5, dated August 17, 1994.

(2) Calculate the disk utilization rate at 12

month intervals after the previous date of

utilization determination, or after installation

of new or recoated disks, in accordance with

paragraph 2.B.(3) of PW ASB No. 6038,

Revision 5, dated August 17, 1994.

(i) For stage 7 through stage 12 HPC disks

designated as high utilization in accordance

with (c)(2), comply with the requirements of

paragraph (c)(1) of this AD.

(ii) For stage 7 through stage 12 HPC disks

designated as low utilization in accordance

with (c)(2), comply with the requirements of

paragraph (d) of this AD.

(d) For low utilization stage 7 through stage

12 HPC disks, perform the following:

(1) For Nickel Cadmium coated disks listed

by Part Number (P/N) in Chart B of PW ASB

No. 6038, Revision 5, dated August 17, 1994,

and Aluminide coated disks listed by P/N in

Chart C of PW ASB 6038, Revision 5, dated

August 17, 1994, inspect, and recoat or

remove from service in accordance with PW

JT8D Engine Manual, P/N 481672, at the time

intervals specified in Table A of this AD.
48802 Federal Register / Vol. 62, No. 180 / Wednesday, September 17, 1997 / Proposed Rules

(2) For Nickel Cadmium coated disks listed

by P/N in Chart C of PW ASB No. 6038,

Revision 5, dated August 17, 1994, inspect

and recoat or remove from service in

accordance with PW JT8D Engine Manual, P/

N 481672, at the time intervals specified in

Table B of this AD.

(3) For Aluminide coated disks listed by P/

N in Chart B of PW ASB No. 6038, Revision

5, dated August 17, 1994, inspect and recoat

or remove from service in accordance with

PW JT8D Engine Manual, P/N 481672, at the

time intervals specified in Table C of this AD.

TABLE A.—INSPECTION INTERVAL FOR

LOW UTILIZATION DISKS NICAD

COATED DISKS FROM CHART B OF

PW ASB NO. 6038, REVISION 5,

DATED AUGUST 17, 1994, AND

ALUMINIDE COATED DISKS FROM

CHART C OF PW ASB NO. 6038,

REVISION 5, DATED AUGUST 17,

1994

Years since new, replated or corrosion inspected (YRSNRC)

per engine manual

Remove to inspect

and recoat or replace

Less than or equal to

5.0 YRSNRC.

By 7 YRSNRC.

Greater than 5.0 but

less than or equal

to 6 YRSNRC.

Within 24 months of

the effective date of

this AD.

Greater than 6 but

less than or equal

to 7 YRSNRC.

Within 18 months of

the effective date of

this AD.

Greater than 7 but

less than or equal

to 8 YRSNRC.

Within 15 months of

the effective date of

this AD.

Greater than 8 but

less than or equal

to 9 YRSNC.

Within 12 months of

the effective date of

this AD.

Greater than 9 but

less than or equal

to 10 YRSNRC.

Before reaching 10

YRSNRC.

Greater than 10 years Before further flight.

TABLE B.—INSPECTION INTERVAL FOR

LOW UTILIZATION DISKS NICAD

COATED DISKS FROM CHART C OF

PW ASB NO. 6038, REVISION 5,

DATED AUGUST 7, 1994.

Years since new, replated or corrosion inspected (YRSNRC)

per engine manual

Remove to inspect

and recoat or replace

Less than or equal to

5.0 YRSNRC.

By 7 YRSNRC.

Greater than 5.0 but

less than or equal

to 6 YRSNRC.

Within 24 months of

the effective date of

this AD.

Greater than 6 but

less than or equal

to 7 YRSNRC.

Within 21 months of

the effective date of

this AD.

Greater than 7 but

less than or equal

to 8 YRSNRC.

Within 18 months of

the effective date of

this AD.

Greater than 8 but

less than or equal

to 9 YRSNC.

Within 15 months of

the effective date of

this AD.

TABLE B.—INSPECTION INTERVAL FOR

LOW UTILIZATION DISKS NICAD

COATED DISKS FROM CHART C OF

PW ASB NO. 6038, REVISION 5,

DATED AUGUST 7, 1994.—Continued

Years since new, replated or corrosion inspected (YRSNRC)

per engine manual

Remove to inspect

and recoat or replace

Greater than 9 but

less than or equal

to 10 YRSNRC.

Within 12 months of

the effective date of

this AD.

Greater than 10 but

less than or equal

to 11 YRSNRC.

Before reaching 11

YRSNRC.

Greater than 11 years Before further flight.

TABLE C.—INSPECTION INTERVAL FOR

LOW UTILIZATION DISKS ALUMINIDE

COATED DISKS FROM CHART B OF

PW ASB NO. 6038, REVISION 5,

DATED AUGUST 17, 1994.

Years since new, replated or corrosion inspected (YRSNRC)

per engine manual

Remove to inspect

and recoat or replace

Less than or equal to

5.0 YRSNRC.

By 7 YRSNRC.

Greater than 5.0 but

less than or equal

to 6 YRSNRC.

Within 24 months of

the effective date of

this AD.

Greater than 6 but

less than or equal

to 7 YRSNRC.

Within 18 months of

the effective date of

this AD.

Greater than 7 but

less than or equal

to 8 YRSNRC.

Within 12 months of

the effective date of

this AD.

Greater than 8 but

less than or equal

to 9 YRSNC.

Before reaching 9

YRSNRC.

Greater than 9 years Before further flight.

(e) For stage 7 through stage 12 HPC disks

that have been recoated in accordance with

paragraphs (b)(1), (c)(1), or (d)(1) of this AD,

designate these disks as high utilization and

perform the following:

(1) For disks installed in an engine that is

part of a high utilization fleet, comply with

the requirements of paragraph (b) of this AD.

(2) For disks installed in an engine that is

part of a low utilization fleet, comply with

the requirements of paragraph (c) of this AD.

(f) For the purpose of this AD, recoat of an

HPC disk is defined as removal and

application of new plating or coating in

accordance with Sections 72–36–41, Repair

02; 72–36–42, Repair 02; 72–36–43, Repair

03; 72–36–44, Repair 03; 72–36–45, Repair

03; or 72–36–46, Repair 03, as applicable, of

PW JT8D Engine Manual P/N 481672.

(g) For the purpose of this AD, part

accessibility is defined as the removal of the

disk from the engine and deblading of that

disk.

(h) For the purpose of this AD, a sub-fleet

is defined as any individual aircraft or any

portion of an operator’s fleet that operates in

a separate and unique route structure,

characterized by different flight lengths,

frequencies, or geographic location.

(i) 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. Operators shall submit

their requests through an appropriate FAA

Principal Maintenance Inspector, who may

add comments and then send it to the

Manager, Engine Certification Office.

Note 4: Information concerning the

existence of approved alternative methods of

compliance with this airworthiness directive,

if any, may be obtained from the Engine

Certification Office.

(j) 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 aircraft to

a location where the requirements of this AD

can be accomplished.

Issued in Burlington, Massachusetts, on

September 10, 1997.

Mark C. Fulmer,

Acting Manager, Engine and Propeller

Directorate, Aircraft Certification Service.

[FR Doc. 97–24799 Filed 9–16–97; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF COMMERCE

National Institute of Standards and

Technology

15 CFR Part 295

[Docket No. 970822201–7201–01]

RIN 0693–AB44

Advanced Technology Program

AGENCY: National Institute of Standards

and Technology, Technology

Administration, Commerce.

ACTION: Notice of proposed rulemaking;

request for comments.

SUMMARY: The National Institute of

Standards and Technology requests

comments on proposed revisions to the

regulations which implement the

Advanced Technology Program (ATP),

found at part 295 of title 15 of the Code

of Federal Regulations. Major changes

proposed today include an increase in

the cost-sharing requirement for large

companies applying as single proposers

in future competitions; modification of

the ATP evaluation criteria for project

selection to place greater emphasis on

joint ventures and consortia with a

broad range of participants; and changes

in the valuation of transfers between

separately-owned joint venture

members and applies to transfers of

goods, including computer software,

and services provided by the transferor

related to the maintenance of those

goods, when those goods or services are