AD 95-16-09 ACTIVE

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Jetstream Model BAe ATP airplanes. This action requires modification of the electrical connections at the switches of the scavenge oil filter and pressure oil filter. This amendment is prompted by reports indicating that the electrical connections were miswired at the switches of the scavenge oil filter and pressure oil filter. The actions specified in this AD are intended to prevent the circulation of unfiltered oil through the engine without warning to the flightcrew, due to miswiring of electrical connections. Unfiltered oil containing contaminants could lead to a precautionary shutdown of the engine.

Final rule; request for comments

95-16-09 JETSTREAM AIRCRAFT LIMITED (Formerly British Aerospace Commercial Aircraft, Limited.): Amendment 39-9329. Docket 95-NM-129-AD.
Applicability: Model BAe ATP airplanes having constructor's numbers 2002 through 2056 inclusive, 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 (b) of this AD 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 the flightcrew from being unaware that unfiltered oil is being circulated through the engine, which may result in a precautionary shutdown of the engine due to the circulation of contaminants in unfiltered oil, accomplish the following:

(a) Within 60 days after the effective date of this AD, modify the wiring connections at the switches of the scavenge oil filter of the reduction gearbox (RGB) and of the pressure oil filter, of both the left and right engines, in accordance with Jetstream BAe ATP Service Bulletin ATP-79-25-10382A, Revision 1, dated May 25, 1995.

(b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved bythe 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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(c) 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.

(d) The modification shall be done in accordance with Jetstream Aircraft Limited BAe ATP Service Bulletin ATP-79-25-10382A, Revision 1, dated May 25, 1995, which contains the following effective pages:

Page number
Revision Level
Shown on page
Date
Shown on page
1, 3, 7
1
May 25, 1995
2,4-6, 8-13
Original
February 10, 1995

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 20041-6029. 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.

(e) This amendment becomes effective on August 18, 1995.

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 BAe ATP airplanes. The CAA advises that it has received reports indicating that the amber light on the central warning panel did not illuminate to warn the flight crew that the engine oil filter would be bypassed. Investigation revealed that the light did not illuminate because the electrical connections were miswired at the switches of the scavenge oil filter of the reduction gearbox (RGB) and of the pressure oil filter. The miswiring configuration was inadvertently included as part of the original wiring design plan for these airplanes and, thus, the miswiring occurred during production. Such miswiring could lead to the circulation of unfiltered oil through the engine without warning to the flightcrew, which could result in a precautionary shutdown of the engine due to contaminants in the unfiltered oil.

Jetstream has issued Service Bulletin ATP-79-25-10382A, Revision 1, dated May 25, 1995, which describes procedures for modification of the electrical connections at the switches of the scavenge oil filter of the RGB and of the pressure oil filter, of the left and right engines. The modification entails rerouting of the 28-volt DC. wiring from pin A to pin C of the switches. The CAA classified this service bulletin as mandatory in order to assure the continued airworthiness of these airplanes in the United Kingdom.

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 the circulation of unfiltered oil through the engine without warning to the flightcrew, which could lead to a precautionary shutdown of the engine due to contaminants in the unfiltered oil. This AD requires modification of the wiring connections at the switches of the scavenge oil filter of the RGB and of the pressure oil filter, of the left and right engines. The actions are required to be accomplished in accordance with the service bulletin 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 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 95-NM-129-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 byreference, 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), 40101, 40113, 44701.

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. 95-NM-129-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 20041-6029. 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.

Gregory Dunn, Aerospace Engineer, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 227-2799; fax (206) 227-1149.