Airworthiness Directives; Jetstream Model ATP Airplanes

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 94-NM-199-AD; Amendment 39-9086; AD 94-25-02]

Airworthiness Directives; Jetstream Model ATP Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that

is applicable to certain Jetstream Model ATP airplanes. This action

requires inspections to detect cracking in certain oil coolers, and

replacement of cracked coolers with serviceable coolers. The amendment

also provides for termination of the inspections by installing certain

reworked and re-identified oil coolers. This amendment is prompted by

reports of cracking in the welded seams of certain oil coolers. The

actions specified in this AD are intended to prevent loss of engine oil

due to cracking in the oil cooler, which may lead to a forced shutdown

of the engine.

DATES: Effective December 22, 1994.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of December 22, 1994.

Comments for inclusion in the Rules Docket must be received on or

before February 6, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-103,

Attention: Rules Docket No. 94-NM-199-AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055-4056.

The service information referenced in this AD may be obtained from

Jetstream Aircraft, Inc., P.O. Box 16029, Dulles International Airport,

Washington, DC. This information may be examined at the FAA, Transport

Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at

the Office of the Federal Register, 800 North Capitol Street, NW.,

suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: William Schroeder, Aerospace Engineer,

Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,

1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone (206)

227-2148; fax (206) 227-1320.

SUPPLEMENTARY INFORMATION: The Civil Aviation Authority (CAA), which is

the airworthiness authority for the United Kingdom, recently notified

the FAA that an unsafe condition may exist on certain Jetstream Model

ATP airplanes. The CAA advises that it has received reports of cracking

in the welded seams of certain engine oil coolers that are cooled by

ram air. Investigation revealed that these oil coolers were welded

incorrectly during the manufacturing process. These defective welds

have been isolated to oil coolers manufactured by Normalair-Garrett

Limited and having part numbers (P/N) 8248C000, 8439C000, and 8714C000.

Such cracking, if not corrected, could result in loss of engine oil,

which may lead to a forced shutdown of the engine.

Jetstream has issued Service Bulletin ATP-79-23, dated August 26,

1994, which describes procedures for repetitive detailed visual

inspections to detect cracking in certain engine oil coolers that are

cooled by ram air. This service bulletin also describes procedures for

replacement of cracked oil coolers with serviceable oil coolers. The

CAA classified this service bulletin as mandatory in order to assure

the continued airworthiness of these airplanes in the United Kingdom.

Jetstream has also issued Service Bulletin ATP-79-24-10360A, dated

September 4, 1994, which describes procedures for rework and re-

identification of oil coolers having P/N's 8248C000, 8439C000, and

8714C000, that are manufactured by Normalair-Garrett Limited.

This airplane model is manufactured in the United Kingdom 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, the CAA has kept the FAA

informed of the situation described above. The FAA has examined the

findings of the CAA, 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 airplanes of the same type design registered

in the United States, this AD is being issued to prevent loss of engine

oil that may lead to a forced shutdown of the engine. This AD requires

repetitive detailed visual inspections to detect cracking in oil

coolers having P/N 8248C000, 8439C000, or 8714C000, and replacement of

cracked oil coolers with serviceable oil coolers. Installation of oil

coolers that have been reworked and re-identified terminates the

requirement for repetitive detailed visual inspections. The actions are

required to be accomplished in accordance with the service bulletins

described previously.

As a result of recent communications with the Air Transport

Association (ATA) of America, the FAA has learned that, in general,

some operators may misunderstand the legal effect of AD's on airplanes

that are identified in the applicability provision of the AD, but that

have been altered or repaired in the area addressed by the AD. The FAA

points out that all airplanes identified in the applicability provision

of an AD are legally subject to the AD. If an airplane has been altered

or repaired in the affected area in such a way as to affect compliance

with the AD, the owner or operator is required to obtain FAA approval

for an alternative method of compliance with the AD, in accordance with

the paragraph of each AD that provides for such approvals. A note has

been included in this final rule to clarify this requirement.

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 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 shall 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 rule must submit a self-addressed,

stamped postcard on which the following statement is made: ``Comments

to Docket Number 94-NM-199-AD.'' 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 that it 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 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

94-25-02 Jetstream Aircraft Limited (Formerly British Aerospace

Commercial Aircraft Limited): Amendment 39-9086. Docket 94-NM-199-

AD.

Applicability: Model ATP airplanes having constructor's numbers

2002 through 2063, inclusive; and equipped with Normalair-Garrett

Limited oil coolers having part number 8248C000, 8439C000, or

8714C000; certificated in any category.

-Note 1: This AD applies to each airplane 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 airplanes 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 paragraph (c) 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 airplane from the applicability of this AD.

Compliance: Required as indicated, unless accomplished

previously.

To prevent loss of engine oil that may lead to a forced shutdown

of the engine, accomplish the following:

(a) Prior to the accumulation of 2,000 total landings on the

engine oil cooler that is cooled by ram air on the left and right

engine, or within 50 hours time-in-service after the effective date

of this AD, whichever occurs later, perform a detailed visual

inspection to detect cracking in the oil cooler, in accordance with

British Aerospace Service Bulletin ATP-79-23, dated August 26, 1994.

(1) If no cracking is detected, repeat this inspection

thereafter at intervals not to exceed 75 hours time-in-service.

(2) If any cracking is detected, prior to further flight,

replace the oil cooler with a serviceable oil cooler having either

part number (P/N) 8439C000-002 or 8714C000-002, in accordance with

British Aerospace Service Bulletin ATP-79-23, dated August 26, 1994,

or with an oil cooler than has been reworked and re-identified in

accordance with British Aerospace Service Bulletin ATP-79-24-10360A,

dated September 4, 1994.

(b) Installation of an oil cooler that has been reworked and re-

identified as either P/N 8714C000-002 or 8439C000-002, in accordance

with British Aerospace Service Bulletin ATP-79-24-10360A, dated

September 4, 1994, constitutes terminating action for the inspection

requirements of this AD.

Note 2: Reworked oil coolers have an initial life limit of 9,000

landings. This life limit and any changes to it are specified in the

Limitations Section in Chapter 5 of the ATP Maintenance Manual.

(c) 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, Standardization Branch, ANM-113,

FAA, Transport Airplane Directorate. Operators shall submit their

requests through an appropriate FAA Principal Maintenance Inspector,

who may add comments and then send it to the Manager,

Standardization Branch, ANM-113.

Note 3: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Standardization Branch, ANM-113.

(d) 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 airplane to a location where

the requirements of this AD can be accomplished.

(e) The inspection shall be done in accordance with Jetstream

Service Bulletin ATP-79-23, dated August 26, 1994, and the rework

and re-identification shall be done in accordance with Jetstream

Service Bulletin ATP-79-24-10360A, dated September 4, 1994. 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 Jetstream Aircraft, Inc., P.O. Box

16029, Dulles International Airport, Washington, DC. Copies may be

inspected at the FAA, Transport Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington; or at the Office of the Federal

Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(f) This amendment becomes effective on December 22, 1994.

Issued in Renton, Washington, on November 30, 1994.

James V. Devany,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-29918 Filed 12-6-94; 8:45 am]

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