# AD 94-19-04: Modify Control Circuit Wiring For Thrust Reversers

- Type: Airworthiness directive
- Status: Current
- Products: Textron BAe.125 Series 1000A
- Effective: October 21, 1994
- Published: September 21, 1994
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-9026
- Docket: 94-NM-35-AD
- Registered aircraft: 22 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/49485C9313B6988C86256A09005E4D3F.0001
- DRS record last changed: January 21, 2026
- Page: https://openairdocs.org/ad/94-19-04

## Summary

This amendment adopts a new airworthiness directive (AD), applicable to certain Raytheon Corporate Jets Model BAe 125-1000A series airplanes, that requires modification of the control circuit wiring for the engine thrust reversers and of the wiring for annunciation of rudder bias status. This amendment is prompted by a report that a single dormant electrical fault in the control circuit of the thrust reversers could cause a thrust reverser to deploy if the pilot selects reverse thrust during the approach phase of flight; and by reports that if an asymmetric thrust reverser condition occurs, the correct rudder bias may not be annunciated before the flight crew applies high reverse thrust. The actions specified by this AD are intended to prevent adversely affected controllability of the airplane.

## The airworthiness directive

94-19-04 RAYTHEON CORPORATE JETS, INC.: Amendment 39-9026. Docket 94-NM-35-AD.

Applicability: Model BAe 125-1000A series airplanes; serial numbers 258151, 258159, and 259003 through 259044 inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent in-flight deployment of a thrust reverser, which could adversely affect the controllability of the airplane, accomplish the following:

  (a) Within 8 months after the effective date of this AD, modify the control circuit wiring for the left and right engine thrust reversers and rudder bias status annunciation, in accordance with Raytheon Corporate Jets Service Bulletin SB.78-9-3662B, dated January 7, 1994.

  (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: 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 Raytheon Corporate Jets Service Bulletin SB.78-9-3662B, dated January 7, 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 Raytheon Corporate Jets Inc., 3 Bishops Square, St. Albans Road West, Hatfield, Hertfordshire, AL109NE, United Kingdom. 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 October 21, 1994.

## Rule preamble

### Supplementary information

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 Raytheon Corporate Jets Model BAe 125-1000A series airplanes was published in the Federal Register on April 29, 1994 (59 FR 22141). That action proposed to require modification of the control circuit wiring for the engine thrust reversers and of the wiring for annunciation of rudder bias status.

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. The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

The FAA estimates that 19 airplanes of U.S. registry will be affected by this AD, that it will take approximately 60 work hours per airplane to accomplish the required actions, and that theaverage labor rate is $55 per work hour. Required parts will cost approximately $1,000 per airplane. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $81,700, or $4,300 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) isnot 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 readas 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:

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A3EU](https://openairdocs.org/tcds/A3EU): Textron Aviation Inc.; names 1 of 50 models: BAe.125 Series 1000A

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 22 (22 by airframe model, 0 by engine model)
- Makers: British Aerospace 9, Corporate Jets 9, Raytheon Corporate Jets 4

Models with the most aircraft:

- [British Aerospace BAE 125 SERIES 1000A](https://openairdocs.org/model/british-aerospace-bae-125-series-1000a): 9 aircraft (airframe model)
- [Corporate Jets BAE 125-1000A](https://openairdocs.org/model/corporate-jets-bae-125-1000a): 9 aircraft (airframe model)
- [Raytheon Corporate Jets BAE 125-1000A](https://openairdocs.org/model/raytheon-corporate-jets-bae-125-1000a): 4 aircraft (airframe model)

All 4 models: https://openairdocs.org/ad/94-19-04/models.md
Every aircraft: https://openairdocs.org/ad/94-19-04/aircraft.md

Its text cites no advisory circulars or STCs.

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