9068 Federal Register / Vol. 62, No. 39 / Thursday, February 27, 1997 / Rules and Regulations

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–ANE–01; Amendment 39–

9936; AD 97–04–12]

RIN 2120–AA64

Airworthiness Directives; Pratt &

Whitney Canada PT6 Series Turboprop

Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule; request for

comments.

SUMMARY: This amendment adopts a

new airworthiness directive (AD) that is

applicable to certain Pratt & Whitney

Canada (PWC) PT6 series turboprop

engines. This action requires a one-time

visual inspection of compressor bleedoff valves (BOVs) to determine if an

affected supplier’s code number is on

the cover; and, if so, this AD requires

the removal of the bleed valve cover

assembly from the compressor bleed

valve housing assembly and inspection

of the cotter pin and the guide shaft pin.

If the cotter pin or guide shaft pin is not

acceptable, this AD requires modifying

the compressor BOV or replacing it with

a serviceable part. This amendment is

prompted by reports of two

malfunctions of compressor BOVs that

resulted in inflight engine power

reduction. The actions specified in this

AD are intended to prevent engine

power reduction due to malfunction of

the compressor BOV, which could result

in a forced landing and loss of the

aircraft.

DATES: Effective March 14, 1997.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of March 14,

1997.

Comments for inclusion in the Rules

Docket must be received on or before

April 28, 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–01, 12 New England Executive

Park, Burlington, MA 01803–5299.

The service information referenced in

this AD may be obtained from Pratt &

Whitney Canada, 1000 Marie-Victorin,

Longueuil, Quebec, Canada J4G 1A1;

telephone (514) 677–9411, fax (514)

647–3620. This information may be

examined at the FAA, New England

Region, Office of the Assistant Chief

Counsel, 12 New England Executive

Park, Burlington, MA; or at the Office of

the Federal Register, 800 North Capitol

Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Diane Cook, Aerospace Engineer, Engine

Certification Office, FAA, Engine and

Propeller Directorate, 12 New England

Executive Park, Burlington, MA 01803–

5299; telephone (617) 238–7134, fax

(617) 238–7199.

SUPPLEMENTARY INFORMATION: Transport

Canada, which is the airworthiness

authority for Canada, recently notified

the FAA that an unsafe condition may

exist on certain Pratt & Whitney Canada

(PWC) PT6 series turboprop engines

installed on single engine aircraft.

Transport Canada advises that it has

received reports of two malfunctions of

compressor bleed-off valves (BOVs) on

PWC PT6A–25C series engines,

resulting in inflight engine power

reduction. The investigation revealed

that the cause of the compressor BOV

malfunction was broken cotter pins. The

debris from the cotter pins interfered

with the movement of the BOV piston,

which resulted in the BOV remaining in

the closed position. The cotter pins

broke due to stress loading from the

guide shaft pin, which was improperly

installed and loose. Further

investigation indicates the compressor

BOVs from the two malfunctions are

from the same supplier. All BOVs

produced from this supplier, which is

approximately 1,000 compressor BOVs

since January 1995, are the suspect

population. The compressor BOVs are

common to all PWC PT6 series engine

models. This condition, if not corrected,

could result in engine power reduction

due to malfunction of the compressor

BOV, which could result in a forced

landing and loss of the aircraft.

Pratt & Whitney Canada has issued

the following Service Bulletins (SBs):

14251, Revision 1, dated December 2,

1996; 13287, Revision, dated December

2, 1996; 12134, Revision 1, dated

December, 1996; 4204, dated December

10, 1996, Original; 3344, Revision 1,

dated December 3, 1996; and 1538,

Revision 3, dated December 2, 1996.

The SBs describe procedures for

visually inspecting BOVs to determine if

the affected supplier’s code number

(No.) is on the cover. If the code No. is

present, the SB describes the procedures

for the removal of the bleed valve cover

assembly from the bleed valve housing

assembly, the inspection of the cotter

pin and the guide shaft pin, the

installation of a new compressor valve

cover assembly if necessary, the

reassembly of the bleed valve cover

assembly to the bleed valve assembly,

and the reidentification of the bleed

valve assembly. Transport Canada

classified these SBs as mandatory and

issued Emergency AD CF–96–24, which

is applicable to all PT6A engines

installed in single engine aircraft, in

order to assure the airworthiness of

these engines in Canada.

This engine model is manufactured in

Canada and is type certificated for

operation in the United States under the

provisions of section 21.29 of the

Federal Aviation Regulations (14 CFR

21.29) and the applicable bilateral

airworthiness agreement. Pursuant to

this bilateral airworthiness agreement,

Transport Canada has kept the FAA

informed of the situation described

above. The FAA has examined the

findings of Transport Canada, reviewed

all available information, and

determined that AD action is necessary

for products of this type design that are

certificated for operation in the United

States.

Since an unsafe condition has been

identified that is likely to exist or

develop on other engines of the same

type design registered in the United

States, the proposed AD would require,

within 100 hours time in service after

the effective date of this AD, but no later

than April 2, 1997, a one-time visual

inspection of compressor BOVs to

determine if the affected supplier’s code

No. 8070, is on the cover. No further

action is required if code No. 8070 is not

on the cover, or if the compressor BOV

has been marked with the

reidentification ‘‘RE71’’ adjacent to the

part number. If code No. 8070 is found

and the compressor BOV has not been

marked for reidentification, this AD

requires inspecting the cotter pin for

any wear indications and the guide shaft

pin for any movement described in the

applicable SB. If the cotter pin or guide

shaft pin is not acceptable, this AD

requires, prior to further flight,

modifying the compressor BOV or

replacing it with a serviceable part. If

the conditions of the cotter pin and the

guide shaft pin are acceptable, this AD

requires the replacement of the cotter

pin, and the reidentification of the bleed

valve assembly in accordance with the

PW SB. The calendar end-date of April

2, 1997, was determined based upon

safety considerations and parts

availability. The actions would be

required to be accomplished in

accordance with the SBs described

previously.

Since a situation exists that requires

the immediate adoption of this

regulation, it is found that notice and

opportunity for prior public comment

hereon are impracticable, and that good
Federal Register / Vol. 62, No. 39 / Thursday, February 27, 1997 / Rules and Regulations 9069

cause exists for making this amendment

effective in less than 30 days.

Comments Invited

Although this action is in the form of

a final rule that involves requirements

affecting flight safety and, thus, was not

preceded by notice and an opportunity

for public comment, comments are

invited on this rule. Interested persons

are invited to comment on this 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

under the caption ADDRESSES. All

communications received on or before

the closing date for comments will be

considered, and this rule may be

amended in light of the comments

received. Factual information that

supports the commenter’s ideas and

suggestions is extremely helpful in

evaluating the effectiveness of the AD

action and determining whether

additional rulemaking action would be

needed.

Comments are specifically invited on

the overall regulatory, economic,

environmental, and energy aspects of

the rule that might suggest a need to

modify the 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 that

summarizes each FAA-public contact

concerned with the substance of this AD

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–01.’’ The

postcard will be date stamped and

returned to the commenter.

The regulations adopted herein will

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 final rule does

not have sufficient federalism

implications to warrant the preparation

of a Federalism Assessment.

The FAA has determined that this

regulation is an emergency regulation

that must be issued immediately to

correct an unsafe condition in aircraft,

and is not a ‘‘significant regulatory

action’’ under Executive Order 12866. It

has been determined further that this

action involves an emergency regulation

under DOT Regulatory Policies and

Procedures (44 FR 11034, February 26,

1979). If it is determined that this

emergency regulation otherwise would

be significant under DOT Regulatory

Policies and Procedures, a final

regulatory evaluation will be prepared

and placed in the Rules Docket. A copy

of it, if filed, may be obtained from the

Rules Docket at the location provided

under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation

safety, Incorporation by reference,

Safety.

Adoption of the Amendment

Accordingly, pursuant to the

authority delegated to me by the

Administrator, the Federal Aviation

Administration amends 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

adding the following new airworthiness

directive:

97–04–12 Pratt & Whitney Canada:

Amendment 39–9936. Docket 97–ANE–

01.

Applicability: Pratt & Whitney Canada

(PWC) PT6 series turboprop engines

manufactured after January 1, 1995, or any

PT6 series engines that have had their

compressor bleed-off valve (BOV) changed

after January 1, 1995, and which are installed

in single-engine aircraft including, but not

limited to the following aircraft: Air Tractor

AT, Ayres Turbo Thrush Commander, Cessna

208 Caravan, Argo Aircraft G169B, Embraer

EMB–312 Tucano, Frakes AF–CAT, Pilatus

PC–6, PC–7, PC–9, and PC–12, Schweitzer

AG–CAT, Aerospatiale Socata TBM–700, and

Raytheon (Beech) T–34C.

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 (e)

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 engine power reduction due to

malfunction of the compressor BOV, which

could result in a forced landing and loss of

the aircraft, accomplish the following:

(a) Within 100 hours time in service (TIS)

after the effective date of this AD, but no later

than April 2, 1997, perform a visual

inspection of compressor BOVs to determine

if the affected supplier’s code number (No.)

8070, is on the cover, in accordance with the

following PWC Service Bulletins (SBs), as

applicable: 14251, Revision 1, dated

December 2, 1996; 13287, Revision 1, dated

December 2, 1996; 12134, Revision 1, dated

December 2, 1996; 4204, dated December 10,

1996, Original; 3344, Revision 1, dated

December 3, 1996; and 1538, Revision 3,

dated December 2, 1996.

(b) No further action is required if code No.

8070 is not on the cover of the compressor

BOV, or if the compressor BOV has been

marked with the reidentification ‘‘RE71’’

adjacent to the part number.

(c) For compressor BOVs with code No.

8070 and no reidentification ‘‘RE71’’

marking, prior to further flight remove and

inspect the cotter pin for any wear

indications and inspect the guide shaft pin

for any movement in accordance with the

applicable SB listed in paragraph (a) of this

AD.

(1) If the cotter pin or guide shaft pin is not

acceptable in accordance with the applicable

SB listed in paragraph (a) of this AD, prior

to further flight, modify the compressor BOV

in accordance with the applicable SB listed

in paragraph (a) of this AD, or replace it with

a serviceable part.

(2) If the cotter pin and the guide shaft pin

are acceptable in accordance with the

applicable SB listed in paragraph (a) of this

AD, prior to further flight, replace the cotter

pin with a serviceable part.

(d) Assemble and install the compressor

bleed valve cover assembly on the housing

assembly and reidentify the bleed valve

assembly with ‘‘RE71’’ in accordance with

the applicable SB listed in paragraph (a) of

this AD.

(e) 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, 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.

(f) 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.

(g) The actions required by this AD shall

be accomplished in accordance with the

following PWC SBs:
9070 Federal Register / Vol. 62, No. 39 / Thursday, February 27, 1997 / Rules and Regulations

Document No. Pages Revision Date

14251 ................................................................................................................................................... 1–9 1 ............. December 2, 1996.

Total pages: 9.

13287 ................................................................................................................................................... 1–11 1 ............. December 2, 1996.

Total pages: 11.

12134 ................................................................................................................................................... 1–8 1 ............. December 2, 1996.

Total pages: 8.

4204 ..................................................................................................................................................... 1–11 Original .. December 10, 1996.

Total pages: 11.

3344 ..................................................................................................................................................... 1–11 1 ............. December 3, 1996.

Total pages: 11.

1538 ..................................................................................................................................................... 1–9 3 ............. December 2, 1996.

Total pages: 9.

This incorporation by reference was

approved by the Director of the Federal

Register in accordance with 5 U.S.C. 552(a)

and 1 CFR part 51. Copies may be obtained

from Pratt & Whitney Canada, 1000 MarieVictorin, Longueuil, Quebec, Canada J4G

1A1; telephone (514) 677–9411, fax (514)

647–3620. Copies may be inspected at the

FAA, New England Region, Office of the

Assistant Chief Counsel, 12 New England

Executive Park, Burlington, MA; or at the

Office of the Federal Register, 800 North

Capitol Street, NW., suite 700, Washington,

DC.

(h) This amendment becomes effective on

March 14, 1997.

Issued in Burlington, Massachusetts, on

February 18, 1997.

James C. Jones,

Acting Manager, Engine and Propeller

Directorate, Aircraft Certification Service.

[FR Doc. 97–4993 Filed 2–26–97; 9:21 am]

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