AD 94-25-02 ACTIVE

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.

Final rule; request for comments

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 thatprovides 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, D.C. 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.

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 thelegal 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 finalrule 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 submittedwill 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.

39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive:

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.

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.