Federal Register / Vol. 62, No. 62 / Tuesday, April 1, 1997 / Proposed Rules 15437

Issued in Renton, Washington, on March

25, 1997.

Darrell M. Pederson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 97–8128 Filed 3–31–97; 8:45 am]

BILLING CODE 4910–13–U

14 CFR Part 39

[Docket No. 97–ANE–07]

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 JT8D series turbofan

engines, that currently requires

inspections of low pressure turbine

(LPT) blade sets for blade shroud

crossnotch wear, and removal, if

necessary. In addition, the current AD

requires, as a terminating action to the

inspections, installation of improved

LPT containment hardware, and

installation of an improved No. 6

bearing scavenge pump bracket bushing.

This action would keep the compliance

actions of the current AD intact but

change the compliance time for full

compliance from the current calendar

end-date to December 31, 1998. This

proposal is prompted by a report of a

fourth stage hub manufacturing defect

that led to the failure of the hub and

subsequent release of LPT blades. The

actions specified by the proposed AD

are intended to prevent damage to the

aircraft resulting from engine debris

following an LPT blade, shaft, or hub

failure.

DATES: Comments must be received by

May 1, 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–07, 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

(617) 238–7175, fax (617) 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–07.’’ 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–07, 12 New

England Executive Park, Burlington, MA

01803–5299.

Discussion

On September 22, 1994, the Federal

Aviation Administration (FAA) issued

airworthiness directive AD 94–20–08,

Amendment 39–9036 (59 FR 51842,

October 15, 1994), applicable to Pratt &

Whitney (PW) JT8D–1, –1A, –1B, –7,

–7A, –7B, –9, –9A, –11, –15, –17, and

–17R series turbofan engines, to require

inspections of low pressure turbine

(LPT) blade sets for blade shroud

crossnotch wear, and removal, if

necessary. In addition, the current AD

requires, as a terminating action to the

inspections, installation of improved

LPT containment hardware, and

installation of an improved No. 6

bearing scavenge pump bracket bushing.

That action was prompted by reports of

uncontained engine failures. That

condition, if not corrected, could result

in damage to the aircraft resulting from

engine debris following an LPT blade,

shaft, or hub failure.

Since the issuance of that AD, the

FAA has developed a two-part risk

management plan intended to address

the threat of blade release due to fourth

stage LPT hub failure. One part of the

management plan is a proposed rule,

Docket No. 96–ANE–32 (62 FR 1299,

January 9, 1997), which proposes the

initial and repetitive inspections and

removal from service of defective disks

in a suspect population. The other part

of the risk management plan is this

proposed AD, which reduces the threat

of uncontainment by changing the

compliance date of the current AD, 94–

20–08. The current AD addresses two

threats to uncontainment in a blade

failure and a shaft fracture by requiring

initial and repetitive inspections of

worn shroud crossnotches on third and

fourth stage LPT blades until improved

containment hardware can be installed.

To address the threat of shaft fracture,

the improved containment hardware

installation is required, as well as an

improved No. 6 bearing scavenge pump

bracket bushing to provide for better

rotor meshing. The compliance deadline

for incorporating the improved

containment hardware and the bearing

bracket bushing is currently December

31, 1999, or 7,000 cycles since

November 14, 1994, or 8,000 hours

since November 14, 1994, whichever

occurs later. To address the additional

threat of uncontainment in the form of

a fourth stage LPT hub fracture, which

results in a blade release, the calendar

end-date for completing compliance to

the requirements of the superseded AD

is changed to December 31, 1998, or

7,000 cycles since November 14, 1994,

or 8,000 hours since November 14,

1994, whichever occurs first.

The FAA has reviewed and approved

the technical contents of the following

service documents: PW ASB No. A5913,

Revision 6, dated October 15, 1993, that
15438 Federal Register / Vol. 62, No. 62 / Tuesday, April 1, 1997 / Proposed Rules

describes the third and fourth stage LPT

blade set inspection procedures and

replacement requirements; PW ASB No.

A6110, Revision 1, dated October 15,

1993, that describes procedures for

installation of improved LPT

containment hardware; PW ASB No.

A6131, dated August 24, 1993, that

describes procedures for installation of

an improved No. 6 bearing scavenge

pump bracket bushing; and PW SB No.

5748, Revision 5, dated August 3, 1993,

that describes procedures for removing

material from the inner platform leading

edge on third and fourth stage LPT vane

and vane cluster assemblies, and

remarking these modified vanes with

new identification numbers.

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 94–20–08 to keep the

compliance actions of the current AD

intact but change the compliance time

for full compliance from the current

calendar end-date to December 31, 1998.

The FAA has determined that the

changes to the AD would neither

increase the scope of the required

actions over the current AD, nor

increase the economic burden on

operators over the costs of complying

with the current AD. While the

proposed new AD would alter the

compliance times, operators should still

be able to perform the required actions

at scheduled maintenance. Therefore

the FAA has determined that this new

AD would result in no additional

economic 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

removing amendment 39–9036 (59 FR

51842, October 15, 1994) and by adding

a new airworthiness directive to read as

follows:

Pratt & Whitney: Docket No. 97–ANE–07.

Supersedes AD 94–20-08, Amendment

39–9036.

Applicability: Pratt & Whitney (PW) JT8D–

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

–17, and –17R turbofan engines, installed on

but not limited to Boeing 737 and 727 series

aircraft, 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 (d)

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 damage to the aircraft resulting

from engine debris following a low pressure

turbine (LPT) blade, shaft, or hub failure,

accomplish the following:

(a) For engines that do not contain fan

exhaust inner front duct segment assemblies

that are installed in accordance with PW

Alert Service Bulletin (ASB) No. 6039,

Revision 3, dated October 15, 1993, or earlier

revisions of PW ASB No. 6039, and either

PW honeycomb third stage outer airseal Part

Number (P/N) 801931, 802097, 797594, or

798279; or Pyromet Industries, Inc.,

honeycomb third stage outer airseal P/N

PI9336; or McClain International, Inc.,

honeycomb third stage outer airseal P/N

M2433; or a turbine case shield assembly

installed in accordance with PW ASB No.

6039, Revision 3, dated October 15, 1993, or

earlier revisions of PW ASB No. 6039; or a

third stage blade set that has third stage

turbine blades that were installed in

accordance with PW SB No. 5331, dated

October 27, 1982, accomplish the following:

(1) Conduct initial and repetitive

inspections on installed third and fourth

stage LPT blade sets, and remove and replace

with serviceable blade sets, as necessary, in

accordance with Part 1 of the

Accomplishment Instructions of PW ASB No.

A5913, Revision 6, dated October 15, 1993;

or PW ASB No. 5913, Revision 5, dated

August 10, 1992; or PW ASB No. 5913,

Revision 4, dated February 20, 1992, as

follows:

(i) Initially inspect the blade shroud

crossnotches of the third stage LPT blade set

when specified in paragraphs (a)(1)(i)(A) or

(a)(1)(i)(B) of this AD, whichever occurs later.

Engines that contain a third stage blade set

that have third stage turbine blades that were

installed per the requirements specified in

PW Service Bulletin No. 5331, dated October

27, 1982, do not require the third stage blade

set inspection.

(A) Inspect within 6,000 cycles or 6,000

hours time in service, whichever occurs first,

since new, since the last blade shroud

crossnotch inspection specified in Section

72–53–12 of PW JT8D Engine Manual P/N

481672, or since last blade shroud crossnotch

repair that was accomplished per the

requirements specified in Section 72–53–12

of PW JT8D Engine Manual P/N 481672; or

(B) Inspect within 1,000 cycles or 1,000

hours time in service since November 14,

1994, whichever occurs first.

(ii) Initially inspect the blade shroud

crossnotches of the fourth stage LPT blade set

when specified in paragraph (a)(1)(ii)(A) or

(a)(1)(ii)(B) of this AD, whichever occurs

later. Engines that contain fan exhaust inner

front duct segment assemblies that were

installed per the requirements of PW ASB

No. 6039, Revision 3, dated October 15, 1993,

or earlier revisions of PW ASB No. 6039, do

not require the fourth stage blade set

inspection.

(A) Inspect within 6,000 cycles or 6,000

hours time in service, whichever occurs first,

since new, since the last blade shroud

crossnotch inspection specified in Section

72–53–13 of PW JT8D Engine Manual P/N

481672, or since last blade shroud crossnotch

repair that was accomplished per the

requirements specified in Section 72–53–13

of PW JT8D Engine Manual P/N 481672; or

(B) Inspect within 1,000 cycles or 1,000

hours time in service since November 14,

1994, whichever occurs first.

(iii) Thereafter, inspect the third and fourth

stage LPT blade sets in accordance with the

procedures and intervals specified in PW

ASB No. A5913, Revision 6, dated October

15, 1993;

(2) At the next shop visit after November

14, 1994; but not later than December 31,

1998, or 8,000 hours time in service since

November 14, 1994, or 7,000 cycles since

November 14, 1994, whichever occurs first,

install the improved inner front fan exhaust

duct and associated hardware in accordance
Federal Register / Vol. 62, No. 62 / Tuesday, April 1, 1997 / Proposed Rules 15439

with Part A of the Accomplishment

Instructions of PW ASB No. A6110, Revision

1, dated October 15, 1993.

(3) At the next access to the third stage

turbine air sealing ring after November 14,

1994, but not later than December 31, 1998,

or 8,000 hours time in service since

November 14, 1994, or 7,000 cycles since

November 14, 1994, whichever occurs first,

install the improved third stage turbine air

sealing ring and associated hardware in

accordance with Part B of the

Accomplishment Instructions of PW ASB No.

A6110, Revision 1, dated October 15, 1993.

Note 2: Third stage turbine outer air seal,

P/N M2533, is an acceptable alternative to

PW P/N 811962 for compliance with this

paragraph.

(4) At the next shop visit after November

14, 1994, but not later than December 31,

1998, or 8,000 hours time in service since

November 14, 1994, or 7,000 cycles since

November 14, 1994, whichever occurs first,

install the improved No. 6 bearing scavenge

pump bracket bushing in accordance with

the Accomplishment Instructions of PW ASB

No. A6131, dated August 24, 1993.

(5) Accomplishment of the installations

required by paragraphs (a)(2), (a)(3), and

(a)(4) of this AD constitutes terminating

action to the repetitive inspections required

by paragraph (a)(1) of this AD.

(b) For engines that do contain fan exhaust

inner front duct segment assemblies that are

installed in accordance with PW ASB No.

6039, Revision 3, dated October 15, 1993, or

earlier revisions of PW ASB No. 6039, and

either PW honeycomb third stage outer

airseal P/N 801931, 802097, 797594, or

798279; or Pyromet Industries, Inc.,

honeycomb third stage outer airseal P/N

PI9336; or McClain International, Inc.,

honeycomb third stage outer airseal P/N

M2433; or a turbine case shield assembly

installed in accordance with PW ASB No.

6039, Revision 3, dated October 15, 1993, or

earlier revisions of PW ASB No. 6039; or a

third stage blade set that has third stage

turbine blades that were installed in

accordance with PW SB No. 5331, dated

October 27, 1982, perform the installations

required by paragraphs (a)(2), (a)(3), and

(a)(4) of this AD, at the times specified in

those respective paragraphs.

(c) For the purpose of this AD, a shop visit

is defined as an engine removal, where

engine maintenance entails separation of

pairs of major mating engine flanges or the

removal of a disk, hub, or spool at a

maintenance facility that is capable of

compliance with the instructions of this AD,

regardless of other planned maintenance,

except for field maintenance type activities

performed at this maintenance facility in lieu

of performing them on-wing or at another

peripheral facility.

(d) 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. The request should be

forwarded through an appropriate FAA

Principal Maintenance Inspector, who may

add comments and then send it to the

Manager, Engine Certification Office.

Note 3: Information concerning the

existence of approved alternative methods of

compliance with this airworthiness directive,

if any, may be obtained from the Engine

Certification Office.

(e) 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

March 24, 1997.

James C. Jones,

Acting Manager, Engine and Propeller

Directorate, Aircraft Certification Service.

[FR Doc. 97–8164 Filed 3–31–97; 8:45 am]

BILLING CODE 4910–13–U

14 CFR Part 39

[Docket No. 96–NM–172–AD]

RIN 2120–AA64

Airworthiness Directives; Airbus Model

A310 and A300–600 Series 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 Airbus Model A310 and A300–

600 series airplanes. This proposal

would require a visual inspection to

detect cracks in the aft mount beam

assembly of the engine; and replacement

of any cracked beam with a new beam

or beam assembly. The proposal also

would require a fluorescent penetrant

inspection to detect cracks in the aft

mount beam assembly of the engine,

and various follow-on actions. This

proposal is prompted by reports

indicating that, apparently due to

manufacturing defects during the

forging process, cracking was found in

two engine aft mount beams. The

actions specified by the proposed AD

are intended to detect and correct such

cracking, which could result in reduced

structural integrity of the aft mount

beam assembly of the engine.

DATES: Comments must be received by

May 12, 1997.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–103,

Attention: Rules Docket No. 96–NM–

172–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

Airbus Industrie, 1 Rond Point Maurice

Bellonte, 31707 Blagnac Cedex, France;

or Pratt & Whitney, 400 Main Street,

East Hartford, Connecticut 06108. This

information may be examined at the

FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton,

Washington.

FOR FURTHER INFORMATION CONTACT:

Charles Huber, Aerospace Engineer,

Standardization Branch, ANM–113,

FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton,

Washington 98055–4056; telephone

(206) 227–2589; fax (206) 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 96–NM–172–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–103, Attention: Rules Docket No.

96–NM–172–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

The Direction Ge ́ne ́rale de l’Aviation

Civile (DGAC), which is the