20194 Federal Register / Vol. 61, No. 88 / Monday, May 6, 1996 / Proposed Rules

(iv) For uninstalled disks on or after the

effective date of this AD, inspect prior to

installation.

(2) Thereafter, perform ECI for cracks at

intervals not to exceed 4,000 CIS since last

ECI.

(3) Prior to further flight, remove cracked

disks and replace with serviceable parts.

(c) Inspect 14th stage HPC disks, P/N’s

704314, 789814, and 790214, in accordance

with NDIP–858, dated November 7, 1995,

attached to PW ASB No. A6232, Revision 1,

dated January 11, 1996, as follows:

(1) Perform an initial ECI for cracks as

follows:

(i) For disks with 2,000 or more CSN, and

2,000 or more CIS since last shop visit, on

the effective date of this AD, inspect within

the next 1,000 CIS after the effective date of

this AD, or at the next shop visit, whichever

occurs first.

(ii) For disks with 2,000 or more CSN, and

less than 2,000 CIS since last shop visit, on

the effective date of this AD, inspect within

3,000 CIS since the last shop visit, or at the

next shop visit, whichever occurs first.

(iii) For disks with 2,000 or more CSN, and

no previous shop visits, inspect within 3,000

CIS after the effective date of this AD, or at

the next shop visit, whichever occurs first.

(iv) For disks with less than 2,000 CSN on

the effective date of this AD, inspect at the

next shop visit after the effective date of this

AD, but before exceeding 3,000 CSN.

(v) For uninstalled disks on or after the

effective date of this AD, inspect prior to

installation.

(2) Thereafter, perform ECI for cracks at

intervals not to exceed 3,000 CIS since last

ECI.

(3) Prior to further flight, remove cracked

disks and replace with serviceable parts.

(d) Within 30 days of inspection, report

inspection results on the form labeled ‘‘14th

and 15th Stage HPC Disk Inspection Report,’’

attached to PW NDIP–858, dated November

7, 1995, attached to PW ASB No. A6232,

Revision 1, dated January 11, 1996, and PW

ASB No. JT9D–7R4–A72–524, dated

December 13, 1995, to the office and fax

number listed on that form. Reporting

requirements have been approved by the

Office of Management and Budget and

assigned OMB control number 2120–0056.

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

is defined as separation of the ‘‘N’’ flange.

(f) 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: Information concerning the existence

of approved alternative methods of

compliance with this airworthiness directive,

if any, may be obtained from the Engine

Certification Office.

(g) 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

April 18, 1996.

Jay J. Pardee,

Manager, Engine and Propeller Directorate,

Aircraft Certification Service.

[FR Doc. 96–11171 Filed 5–3–96; 8:45 am]

BILLING CODE 4910–13–U

14 CFR Part 39

[Docket No. 96–ANE–02]

Airworthiness Directives; Pratt &

Whitney JT8D–200 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–200 series

turbofan engines, that currently requires

periodic inspection of fan blades for

locked rotors and foreign object damage

(FOD), unlocking of shrouds if

necessary, lubrication of fan blade

shrouds, and dimensional restoration of

the fan blade leading edge. This action

would add a requirement to install

improved design fan blades as

terminating action for the inspections.

This proposal is prompted by the

introduction into service of improved

design fan blades. The actions specified

by the proposed AD are intended to

prevent fan blade failure, which can

result in damage to the aircraft.

DATES: Comments must be received by

July 5, 1996.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), New England

Region, Office of the Assistant Chief

Counsel, Attention: Rules Docket No.

96–ANE–02, 12 New England Executive

Park, Burlington, MA 01803–5299.

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:

Mark A. Rumizen, Aerospace Engineer,

Engine Certification Office, FAA, Engine

and Propeller Directorate, 12 New

England Executive Park, Burlington, MA

01803–5299; telephone (617) 238–7137,

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 96–ANE–02.’’ 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. 96–ANE–02, 12 New

England Executive Park, Burlington, MA

01803–5299.

Discussion

On June 5, 1995, the Federal Aviation

Administration (FAA) issued

airworthiness directive (AD) 95–12–19,

Amendment 39–9270 (60 FR 31388,

June 15, 1995), applicable to certain

Pratt & Whitney (PW) JT8D–200 series

turbofan engines, to require a periodic

inspection of fan blades for locked

rotors and foreign object damage (FOD),

unlocking of shrouds if necessary,

lubrication of the fan blade shrouds, and

dimensional restoration of the fan blade

leading edge. That action was prompted

by the determination that fan blades can

fail due to high cycle fatigue (HCF)

cracking. This HCF cracking can be
Federal Register / Vol. 61, No. 88 / Monday, May 6, 1996 / Proposed Rules 20195

caused by FOD, locked shrouds, which

can reduce blade vibratory dampening,

and leading edge erosion, which can

produce blade flutter. That condition, if

not corrected, could result in fan blade

failure, which can result in damage to

the aircraft.

Since the issuance of that AD, the

manufacturer has introduced into

service fan blades with an improved

design configuration that is more

resistant to HCF-induced failures.

The FAA has reviewed and approved

the technical contents of PW Alert

Service Bulletin (ASB) No. A6241, dated

January 25, 1996, that describes

procedures for inspection of fan blades

for locked rotors and FOD, unlocking of

shrouds if necessary, lubrication of fan

blade shrouds, and dimensional

restoration of the fan blade leading edge.

This ASB also provides procedures for

modification or replacement of fan

blades with an improved design

configuration that is more resistant to

HCF-induced failures.

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 95–12–19 to continue to

require the inspection and maintenance

requirements of that AD, and to add a

requirement to modify or install the

improved design fan blades as

terminating action for those inspections

and maintenance requirements.

The FAA estimates that 1,100 engines

installed on aircraft of U.S. registry

would be affected by this proposed AD,

that it would take approximately 19

work hours per engine to accomplish

the proposed actions, and that the

average labor rate is $60 per work hour.

The FAA also estimates that the parts

modification would cost is $2,720 per

engine, which includes a manufacturer’s

discount of $1,700 per engine. Based on

these figures, the total cost impact of the

proposed AD on U.S. operators is

estimated to be $4,246,000.

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 USC 106(g), 40113, 44701.

§ 39.13 [Amended]

2. Section 39.13 is amended by

removing amendment 39–9270 (60 FR

31388, June 15, 1995) and by adding a

new airworthiness directive to read as

follows:

Pratt & Whitney: Docket No. 96–ANE–02.

Supersedes AD 95–12–19, Amendment

39–9270.

Applicability: Pratt & Whitney (PW)

Models JT8D–209, –217, –217A, –217C, and

–219 turbofan engines that have not

incorporated PW Service Bulletin (SB) No.

6193, dated October 31, 1994, or with fan

blade, Part Numbers (P/N’s) 798821, 798821–

001, 808121, 808121–001, 809221, 811821,

851121, 851121–001, 5000021–02,5000021–

022, and 5000021–032 installed. These

engines are installed on but not limited to

McDonnell Douglas MD–80 aircraft.

Note: This 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 use the authority

provided in paragraphs (d) and (e) to request

approval from the FAA. This approval may

address either no action, if the current

configuration eliminates the unsafe

condition, or different actions necessary to

address the unsafe condition described in

this AD. Such a request should include an

assessment of the effect of the changed

configuration on the unsafe condition

addressed by this AD. In no case does the

presence of any modification, alteration, or

repair remove any engine from the

applicability of this AD.

Compliance: Required as indicated, unless

accomplished previously.

To prevent fan blade failure, which can

result in damage to the aircraft, accomplish

the following:

(a) Inspect fan blades and shrouds, unlock

fan blade shrouds, lubricate fan blade

shrouds, restore leading edge dimensions,

and modify or install improved design fan

blades in accordance with the schedule and

procedures described in Parts 1, 2, and 3 of

the Accomplishment Instructions of PW

Alert Service Bulletin (ASB) No. A6241,

dated January 25, 1996.

(b) Modification of fan blades to the

improved design configuration or installation

of improved design fan blades in accordance

with Part 3 of the Accomplishment

Instructions of PW ASB No. A6241, dated

January 25, 1996, constitutes terminating

action to the inspections and maintenance

actions described in Parts 1 and 2 of that

ASB.

(c) For the purpose of this AD, the

accomplishment effective date to be used for

determination of compliance intervals, as

required by Section 2 of PW ASB No. A6241,

dated January 25, 1996, is defined as the

effective date of this AD.

(d) For the purpose of this AD, ‘‘repair’’ as

specified in Part 3, Paragraph A.(1)(b) of the

Accomplishment Instructions of PW ASB No.

A6241, dated January 25, 1996, is defined as

the refurbishment of fan blades in accordance

with Part 3, Paragraph C of the

Accomplishment Instructions of PW ASB No.

A6241, dated January 25, 1996.

(e) Alternative methods of compliance that

have been approved for AD 95–12–19 are

applicable for this AD and additional

approval is not required.

(f) 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: Information concerning the existence

of approved alternative methods of

compliance with this airworthiness directive,

if any, may be obtained from the Engine

Certification Office.

(g) 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

April 1, 1996.

Jay J. Pardee,

Manager, Engine and Propeller Directorate,

Aircraft Certification Service.

[FR Doc. 96–11168 Filed 5–3–96; 8:45 am]

BILLING CODE 4910–13–U