AD 94-22-11

This amendment adopts a new airworthiness directive (AD), applicable to certain British Aerospace Model ATP airplanes, that requires modification of the power supply for the communications system. This amendment is prompted by reports of loss of power to the communications system due to an electrical fault in the ground crew jack box or the handset of the public address (PA) system. The actions specified by this AD are intended to prevent the inability of the flight crew to communicate with passengers via the PA system and with air traffic control due to loss of power to the communication system, which may lead to unsafe operation of the airplane.

Final rule

94-22-11 BRITISH AEROSPACE: Amendment 39-9061. Docket 94-NM-41-AD.
Applicability: Model ATP airplanes having constructor's numbers 2002 through 2063 inclusive, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent the inability of the flight crew to communicate with passengers via the public address system and with air traffic control due to loss of power to the communication system, which may lead to unsafe operation of the airplane, accomplish the following:

(a) Within 675 hours time-in-service after the effective date of this AD, modify the power supply of the communications system (Modification 35288A) in accordance with Jetstream Service Bulletin ATP-23-21-35288A, Revision 2, dated February 15, 1994.

NOTE 1: Jetstream Service Bulletin ATP-23-21-35288A Erratum No. 1, dated March 14, 1994; Erratum No. 2, dated April 25, 1994; and Erratum No. 4, dated June 1, 1994; describe certain editorial corrections to Jetstream Service Bulletin ATP-23-21-35288A, Revision 2.

(b) 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 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 Service Bulletin ATP-23-21-35288A, Revision 2, dated February 15, 1994, which contains the following list of effective pages:

Page Number
Revision Level
Shown on Page
Date
Shown on Page

1, 3, 6, 15
2
February 15, 1994

2, 4, 5, 7-14,
1
February 1, 1994
16-19

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, Incorporated, 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 December 12, 1994.

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 British Aerospace Model ATP airplanes series airplanes was published in the Federal Register on May 11, 1994 (59 FR 24382). That action proposed to require modification of the power supply for the communications system.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public.

Since issuance of the notice, Jetstream has issued errata sheets Numbers 1, 2, and 4, pertaining to Service Bulletin ATP-23-21-35288A. Erratum No. 1 was issued March 14, 1994, and adds an additional part number to the list of pertinent cable looms that appeared in Revision 2 of Jetstream Service Bulletin ATP-23-21-35288A. Erratum No. 2 was issued April 25, 1994, and corrects certain editorial errors that appeared in that same service bulletin. Erratum No. 4 was issued June 1, 1994, and includes an additional reference to the fuse and circuit breaker index that appeared in that same service bulletin. The final rule has been revised to add a note referencing the existence of these errata sheets. These errata sheets do not require any further work by operators who have previously complied with Jetstream Service Bulletin ATP-23-21-35288A, Revision 2, dated February 15, 1994.

After careful review of the available data, the FAA has determined that air safety and the public interest require the adoption of the rule with the change previously described. The FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD.

The FAA estimates that 10 airplanes of U.S. registry will be affected by this AD, that it will take approximately 30 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will be provided by the manufacturer at no cost to the operator. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $18,000, or $1,800 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 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: