AD 95-12-13

This amendment adopts a new airworthiness directive (AD), applicable to certain Jetstream Model ATP airplanes, that requires installation of modified engine de-ice timers, modification of the electrical wiring for the duct heat of the engine air intake, and installation of a time delay for the de-ice system in the air intake duct of the right engine. This amendment also requires associated revisions to the Airplane Flight Manual. This amendment is prompted by reports of ice that accreted in the engine air intake ducts and was ingested into the engine; this resulted in engine power rollback (loss of engine power). The actions specified by this AD are intended to prevent loss of multiple engine power during flight in icing conditions.

Final rule

95-12-13 JETSTREAM AIRCRAFT LIMITED (Formerly British Aerospace Commercial Aircraft, Limited): Amendment 39-9263. Docket 94-NM-168-AD.
Applicability: Model Model ATP airplanes having constructor numbers 2002 through 2063 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 (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 onthe 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 engine power rollback during flight in icing conditions, due to ingestion of accreted ice, accomplish the following:

(a) For airplanes having constructor numbers 2002 through 2056 inclusive: Within 90 days after the effective date of this AD, install modified de-ice timers for the left and right engines (Modification 30146A), in accordance with Jetstream Aircraft Limited Service Bulletin ATP-30-39-30146A, dated July 29, 1994; and revise the FAA-approved Airplane Flight Manual (AFM) to include the information specified in Temporary Revision T/41, Issue 1, dated November 15, 1994.

NOTE 2: The revision of the AFM required by this paragraph may be accomplished by inserting a copy of Temporary Revision T/41 in the AFM. When this temporary revision has been incorporated into general revisions of the AFM, the general revisions may be inserted in the AFM, provided that the information contained in the general revisions is identical to that specified in Temporary Revision T/41.

(b) For airplanes having constructor numbers 2002 through 2063 inclusive: Within 90 days after the effective date of this AD, accomplish paragraphs (b)(1) and (b)(2) of this AD:

(1) Install the modified electrical wiring for the flexible ducts and lips of the engine air intake (Modification 30143A) in accordance with Jetstream Aircraft Limited Service Bulletin ATP-30-37-30143A, dated August 1, 1994, or Revision 1, dated September 5, 1994.

(2) Install the automated 20-second delay system (Modification 35285A) to ensure that the left engine de-ice systems are turned on prior to turning on the right engine de-ice systems, in accordance with Jetstream Aircraft Limited Service Bulletin ATP-30-30-35285A, dated July 15, 1994; and revise the FAA-approved AFM to include the information specified in Temporary Revision T/40, Issue 1, dated August 3, 1994.

NOTE 3: The revision of the AFM required by this paragraph may be accomplished by inserting a copy of Temporary Revision T/40 in the AFM. When this temporary revision has been incorporated into general revisions of the AFM, the general revisions may be inserted in the AFM, provided that the information contained in the general revisions is identical to that specified in Temporary Revision T/40.

(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 4: Information concerning theexistence 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 installation shall be done in accordance with the following Jetstream service bulletins, as applicable, which contain the specified effective pages:

Service Bulletin
Referenced and Date
Page Number
Revision Level
Shown on Page
Date
Shown on Page
ATP-30-39-30146A
Original Issue
July 29, 1994
1-7
Original
July 29, 1994
ATP30-37-30143A
Original Issue
August 1, 1994
1-15
Original
August 1, 1994
ATP30-37-30143A
Revision 1

September 5, 1994
1-3, 5-10,
14-17

4, 11-13
1

Original
September 5, 1994

August 1, 1994
ATP-30-30-35285A
Original Issue
July 15, 19941-19
Original
July 15, 1994

The amendment of the AFM shall be done in accordance with Temporary Revision T/41, Issue 1, dated November 15, 1994; or Temporary Revision T/40, Issue 1, dated August 3, 1994; as applicable. 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.

(f) This amendment becomes effective on July 26, 1995.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Jetstream Model ATP airplanes was published in the Federal Register on December 20, 1994 (59 FR 65516). That action proposed to require installation of new de-ice timers and an associated revision to the AFM; installation of a system that automates a 20-second delay between turning on the left engine intake de-ice system and turning on the right engine intake de-ice system; and installation of modified electrical wiring for the flexible ducts and lips of the engine air intake.

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the single comment received.

The commenter supports the proposed rule.

After careful review of the available data, including the comment noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

The FAA estimates that 10 airplanes of U.S. registry will be affected by this AD, that it will take approximately 72 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts would be provided by the manufacturer at no cost to the operators. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $43,200, or $4,320 per airplane.

The total cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

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.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it 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 AmendmentAccordingly, 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: