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

64523

Vol. 62, No. 235

Monday, December 8, 1997

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95–ANE–38]

RIN 2120–AA64

Airworthiness Directives; Pratt &

Whitney JT9D–7R4 Series Turbofan

Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Supplemental notice of

proposed rulemaking; reopening of

comment period.

SUMMARY: This notice revises an earlier

proposed airworthiness directive (AD),

applicable to Pratt & Whitney (PW)

JT9D–7R4 series turbofan engines, that

would have required removal of web

material at ten bosses on the diffuser

case assembly, inspections, shotpeening

of the area, and remarking the diffuser

case assemblies with a new part

number. That proposal was prompted

by reports of cracks in the aft corners of

the bosses. This action revises the

proposed rule by adding initial and

repetitive on-wing eddy current

inspections (ECI) of the affected bosses

for cracks, and replacement, if found

cracked, with serviceable parts. In

addition, this action revises the initial

accomplishment time for the previously

proposed actions. Finally, this action

adds further etches, fluorescent

penetrant inspections (FPIs), x-ray

inspections, and shotpeening to the

shop requirements, and provides an

optional terminating action in the form

of a redesigned diffuser case. The

actions specified by this proposed AD

are intended to prevent diffuser case

assembly rupture, which could result in

an uncontained engine failure, engine

fire, and damage to the aircraft.

DATES: Comments must be received by

February 6, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), New England

Region, Office of the Assistant Chief

Counsel, Attention: Rules Docket No.

95–ANE–38, 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, Publications

Department, Supervisor Technical

Publications Distribution, M/S 132–30,

400 Main St., East Hartford, CT 06108;

telephone (860) 565–7700, 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: Tara

Goodman, Aerospace Engineer, Engine

Certification Office, FAA, Engine and

Propeller Directorate, 12 New England

Executive Park, Burlington, MA 01803–

5299; telephone (781) 238–7130, 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 95–ANE–38.’’ 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. 95–ANE–38, 12 New

England Executive Park, Burlington, MA

01803–5299.

Discussion

A proposal to amend part 39 of the

Federal Aviation Regulations (14 CFR

part 39) to add an airworthiness

directive (AD), applicable to Pratt &

Whitney (PW) JT9D–7R4 series turbofan

engines, was published as a notice of

proposed rulemaking (NPRM) in the

Federal Register on August 23, 1995 (60

FR 43730). That NPRM would have

required removing webs of material at

ten bosses on the diffuser case assembly,

performing a fluorescent penetrant

inspection (FPI) and x-ray inspection of

the reworked area, performing furnace

stress relief if a local stress relief had

been previously accomplished,

shotpeening the reworked area, and

remarking the diffuser case assemblies

with a new part number. That NPRM

was prompted by reports of cracks at the

aft corners of bosses on the diffuser case

assembly. No engine failures have

resulted from these cracks. The cracks

occur in webs of material at 10 diffuser

case bosses that were a result of a

machining operation during original

manufacture. The webs of material

create stress concentrations that can

cause a crack to start. That condition, if

not corrected, could result in diffuser

case assembly rupture, which could

result in an uncontained engine failure,

engine fire, and damage to the aircraft.

Since the issuance of that NPRM, the

FAA received three comments regarding

the actions proposed by this AD.

One commenter states basic

concurrence with the intent of the AD,

but recommends a change in the

accomplishment time, from the next

shop visit, not to exceed 6,000 cycles in

service (CIS) after the effective date of

this AD, to the next diffuser module
64524 Federal Register / Vol. 62, No. 235 / Monday, December 8, 1997 / Proposed Rules

disassembly after the effective date of

this AD. The commenter states that the

original accomplishment time causes an

undue scheduling burden, and estimates

that an additional $469,608 will be

incurred without the revision to the

accomplishment time. The FAA

concurs. The FAA has revised the

accomplishment time, and has added

initial and repetitive on-wing and shop

eddy current inspections (ECI) of the

bosses to mitigate any additional safety

risk incurred by the extension of the

accomplishment time.

One commenter recommends a

change to the work hours estimate in the

economic analysis. The commenter

states that 44 work hours of labor are

necessary to perform the actions

required by this AD, instead of the 20

work hours specified in the NPRM, and

indicates that 44 work hours is more

consistent with the maintenance

environment of airlines and repair

facilities. The FAA concurs, and has

revised the economic analysis

accordingly, but has increased the work

hours estimate further in this

supplemental NPRM to include the time

required to accomplish the additional

actions proposed in this supplemental

NPRM.

In addition, since issuance of the

NPRM, the FAA has determined the

need to enhance the AD by adding

further etches, fluorescent penetrant

inspections (FPIs), x-ray inspections,

and shotpeening to the shop

requirements. The FAA estimates that

an additional two hours of labor will be

necessary to access and perform the

enhanced inspection of the diffuser

case. The FAA also has determined the

need to clarify, based on overhaul shop

concerns regarding repairable diffuser

cases, that cracks under the rail are

acceptable as long as total weld bead

length is less than 1.5 inches. This

supplemental NPRM has been revised

accordingly to incorporate these

changes.

Finally, this supplemental NPRM

references PW Service Bulletin (SB) No.

JT9D–7R4–72–527, Revision 3, dated

April 16, 1997, Revision 2, dated July

12, 1996, and Revision 1, dated May 3,

1996, that describes the on-wing ECIs

required by this AD, and SB No. JT9D–

7R4–72–469, Revision 3, dated January

24, 1996, that describes the new shop

procedures required by this AD. In

addition, installation of diffuser case,

part number 815736, in accordance with

the requirements of PW SB No. JT9D–

7R4–72–533, dated August 29, 1996,

constitutes terminating action for this

AD.

Since these changes expand the scope

of the originally proposed rule, the FAA

has determined that it is necessary to

reopen the comment period to provide

additional opportunity for public

comment.

There are approximately 690 engines

of the affected design in the worldwide

fleet. The FAA estimates that 137

engines would be affected by this

proposed AD, that it would take

approximately 46 work hours per engine

to accomplish the proposed actions, and

that the average labor rate is $60 per

work hour. Based on these figures, the

total cost impact of the proposed AD on

U.S. operators is estimated to be

$378,120.

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:

Pratt & Whitney: Docket No. 95–ANE–38.

Applicability: Pratt & Whitney (PW) JT9D–

7R4 series turbofan engines, installed on but

not limited to Airbus A300, A310 series, and

Boeing 747, 767 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 (g)

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 diffuser case assembly rupture,

which could result in an uncontained engine

failure, engine fire, and damage to the

aircraft, accomplish the following:

(a) For assembled diffuser case assembly,

Part Numbers (P/Ns) 789996, 789996–002,

789996–003, 790541, 790541–002, 790541–

003, 798379, 798379–003, 798379–004,

5000366–002, 5000366–021, 5000366–022,

5004770–01, 5004770–022, and 5004770–

023, perform initial on-wing eddy current

inspection (ECI) or initial and repetitive

fluorescent penetrant inspection (FPI) or ECI

shop inspections of the diffuser case bosses

in accordance with PW Service Bulletin (SB)

No. JT9D–7R4–72–527, Revision 3, dated

April 16, 1997, or Revision 2, dated July 12,

1996, or Revision 1, dated May 3, 1996,

within 250 cycles in service (CIS) after the

effective date of this AD, as follows:

(1) For assembled diffuser cases in the

shop, that have not been previously

inspected in accordance with any one of the

requirements of the SBs cited in paragraph

(a) of this AD, perform an initial FPI or ECI

of both rear corners of all 10 diffuser case

mounting bosses and 2 case mount pads in

accordance with any one of the SBs cited in

paragraph (a) of this AD, or,

(i) If cracks are found, perform repairs in

accordance with the applicable Engine

Manual, Chapter/Section 72–41–02, Repair–

28.

(ii) Thereafter, perform inspections within

650 CIS since last inspection, in accordance

with any one of the SBs cited in paragraph

(a) of this AD.

(2) For assembled diffuser cases that are

installed on-wing, that have not been

previously inspected in accordance with any

of the requirements of this AD, perform an

initial ECI of both rear corners of boss six,

located at the six o’clock position, in

accordance with any one of the SBs cited in

paragraph (a) of this AD:
Federal Register / Vol. 62, No. 235 / Monday, December 8, 1997 / Proposed Rules 64525

(i) If a crack indication is found, borescope

or FPI the area where the crack was

indicated, in accordance with any one of the

SBs cited in paragraph (a) of this AD.

Depending on the crack size, accomplish the

following:

(A) The diffuser case may continue in

service provided it is inspected at intervals

not to exceed 50 CIS since last borescope

inspection, if the circumferential crack

dimension ‘‘B’’, is less than 0.5 inches long,

and the axial crack dimension ‘‘A’’ is less

than 0.8 inches long, in accordance with any

one of the SBs cited in paragraph (a) of this

AD.

(B) The diffuser case may continue in

service for a maximum of 5 CIS, if the axial

crack dimension ‘‘A’’ is equal to or greater

than 0.8 inches but less than or equal to 1.0

inch, in accordance with any one of the SBs

cited in paragraph (a) of this AD.

(C) Remove from service prior to further

flight the diffuser case when the axial crack

dimension ‘‘A’’ is greater than 1.0 inch, in

accordance with any one of the SBs cited in

paragraph (a) of this AD.

(ii) Diffuser cases with no cracks at boss

six, perform an ECI at intervals not to exceed

650 CIS since the last boss 6 inspection, in

accordance with any one of the SBs cited in

paragraph (a) of this AD.

(b) At the next diffuser module

disassembly when all hardware is stripped

off the diffuser case, but not to exceed 6,000

CIS after the effective date of this AD, inspect

diffuser cases, P/Ns 790541, 798379, 789996,

5004770–01, or 5000366–02, for existence of

web material at ten boss locations, in

accordance with PW SB No. JT9D–7R4–72–

469, Revision 3, dated January 24, 1996.

(1) Rework the diffuser case assembly in

accordance with PW SB No. JT9D–7R4–72–

469, Revision 3, dated January 24, 1996. This

rework removes web material at 10 boss

locations.

(2) Perform an etch and an ultra-high

fluorescent penetrant inspection (FPI) of the

reworked areas in accordance with PW SB

No. JT9D–7R4–72–469, Revision 3, dated

January 24, 1996, to ensure that there are no

crack indications.

(3) If a crack indication is discovered,

repair, and perform an ECI and an FPI in

accordance with Engine Manual Section 72–

41–02, Repair–28, or remove the diffuser case

from service and replace with a serviceable

part.

(4) Perform an x-ray inspection of the

reworked areas (all 10 boss locations and 2

mount pad locations) in accordance with PW

SB No. JT9D–7R4–72–469, Revision 3, dated

January 24, 1996, to ensure that there are no

crack indications. Additionally, the x-ray

inspection is performed to assure that there

are no cracks, incomplete fusion, incomplete

penetration, voids, porosity, or inclusions

from previous local weld repairs. If any of

these defects are discovered, repair per PW

JT9D–7R4 Engine Manual, Section 72–41–02,

Repair–28, or remove the diffuser case from

service and replace with a serviceable part.

(5) Determine if local stress relief was

performed previously, and if weld repairs

have been performed at any of the boss

locations described in the above SB, through

reviewing maintenance records. If

maintenance records cannot be located, or

maintenance records indicate that a weld

repair with no stress relief or a weld repair

with a local stress relief that has been

performed at any of the 10 boss locations or

2 mount pad locations, perform furnace

stress relief and FPI of the diffuser case

assemblies in accordance with PW SB No.

JT9D–7R4–72–469, Revision 3, dated January

24, 1996.

(6) Shotpeen the reworked areas in

accordance with PW SB No. JT9D–7R4–72–

469, Revision 3, dated January 24, 1996.

(7) Remark the diffuser case assembly with

a new part number in accordance with PW

SB No. JT9D–7R4–72–469, Revision 3, dated

January 24, 1996.

(c) At the next shop visit, but not to exceed

6,000 CIS after the effective date of this AD,

for diffuser case assembly, P/Ns 790541–002,

790541–003, 798379–003, 798379–004,

789996–002, 789996–003, 5000366–021,

5000366–022, 5004770–022, and 5004770–

023, that have been previously reworked to

remove web material at any boss locations

prior to the effective date of this AD in

accordance with the original issue of PW SB

No. JT9D–7R4–72–469, dated October 2,

1992, accomplish the following:

(1) Unless maintenance records indicate

that x-ray inspections were performed at the

last shop visit where diffuser case repairs

were accomplished at the 10 boss locations,

prior to the effective date of this AD, in

accordance with PW JT9D–7R4 Engine

Manual, Section 72–41–02, Repair–28,

perform an x-ray inspection of all 10 boss

locations and 2 mount pad locations in

accordance with the x-ray requirements of

PW JT9D–7R4 Engine Manual, Section 72–

41–02, Repair–28.

(2) Determine if any previous weld repairs

have been performed at any of the boss

locations described in the above SB through

reviewing maintenance records. If

maintenance records cannot be located, or

maintenance records indicate that a weld

repair with no stress relief or with a local

stress relief has been performed at any of the

boss locations, perform furnace stress relief,

FPI, and shotpeen diffuser case assemblies in

accordance with PW SB No. JT9D–7R4–72–

469, Revision 3, dated January 24, 1996.

(d) For the purpose of this AD, shop visit

is defined as separation of diffuser case at

‘‘K’’ and ‘‘M’’ flanges.

(e) For the purpose of this AD, an

assembled diffuser case in the shop is

defined as a diffuser case either mounted or

dismounted from the engine, but with

external hardware removed to perform the

inspections.

(f) Installation of diffuser case, P/N 815736,

in accordance with the requirements of PW

SB No. JT9D–7R4–72–533, dated August 29,

1996, constitutes terminating action for this

AD.

(g) 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 2: Information concerning the

existence of approved alternative methods of

compliance with this airworthiness directive,

if any, may be obtained from the Engine

Certification Office.

(h) 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

November 28, 1997.

Jay J. Pardee,

Manager, Engine and Propeller Directorate,

Aircraft Certification Service.

[FR Doc. 97–31967 Filed 12–5–97; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 71

[Airspace Docket No. 97–ASO–26]

Proposed Amendment to Class E

Airspace; New Bern, NC

AGENCY: Federal Aviation

Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking.

SUMMARY: This notice proposes to

amend the Class E airspace area at New

Bern, NC. The required weather

observation information is available on

a continuous basis to the air traffic

control providing service to New Bern,

Craven County, NC, Airport. Therefore,

the Class E surface area airspace at New

Bern, NC, meets the requirement for

modification from part time to

continuous.

DATES: Comments must be received on

or before January 7, 1998.

ADDRESSES: Send comments on the

proposal in triplicate to: Federal

Aviation Administration, Docket No.

97–ASO–26, Manager, Airspace Branch,

ASO–520, P.O. Box 20636, Atlanta,

Georgia 30320.

The official docket may be examined

in the Office of the Assistant Chief

Counsel for Southern Region, Room 550,

1701 Columbia Avenue, College Park,

Georgia 30337, telephone (404) 305–

5586.

FOR FURTHER INFORMATION CONTACT:

Nancy B. Shelton, Airspace Branch, Air

Traffic Division, Federal Aviation

Administration, P.O. Box 20636,

Atlanta, Georgia 30320; telephone (404)

305–5581.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested parties are invited to

participate in this proposed rulemaking