# AD 85-07-08: Audio Communication System

- Type: Airworthiness directive
- Status: Current
- Products: BH.125 Series 400A, BH.125 Series 600A, DH.125 Series 1A, DH.125 Series 1A/R-522, DH.125 Series 1A/S-522, DH.125 Series 1A-522, DH.125 Series 3A, DH.125 Series 3A/R, DH.125 Series 3A/RA, DH.125 Series 400A, HS.125 Series 600A and HS.125 Series 700A
- Effective: May 13, 1985
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-5032
- Registered aircraft: 26 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/7979FD1578A9E393862569F3004C9807.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/85-07-08

## The airworthiness directive

85-07-08 BRITISH AEROSPACE: Amendment 39-5032. Applies to Model HS/BH/DH 125 series airplanes with the serial numbers listed in the applicability statement of British Aerospace HS 125 Service Bulletin 23-21-(8765), dated March 22, 1983. Compliance is required within 180 days after the effective date of this AD, unless previously accomplished. To prevent failure of the audio communication system, accomplish the following:

A. Modify the power supply system in accordance with the accomplishment instructions of British Aerospace HS 125 Service Bulletin 23-21-8765, dated March 22, 1983.

B. Alternate means of compliance which provide an acceptable level of safety may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region.

C. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of inspections and/or modifications required by this AD.

Thisamendment becomes effective May 13, 1985.

## 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 12 of 50 models: HS.125 Series 600A, HS.125 Series 700A, DH.125 Series 1A/R-522, BH.125 Series 400A, BH.125 Series 600A, DH.125 Series 400A, DH.125 Series 3A/R, DH.125 Series 1A…

## 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: 26 (26 by airframe model, 0 by engine model)
- Makers: British Aerospace 14, Hawker Siddeley 11, Raytheon 1

Models with the most aircraft:

- [British Aerospace HS 125-700A](https://openairdocs.org/model/british-aerospace-hs-125-700a): 14 aircraft (airframe model)
- [Hawker Siddeley HS.125 SERIES 700A](https://openairdocs.org/model/hawker-siddeley-hs-125-series-700a): 7 aircraft (airframe model)
- [Hawker Siddeley BH.125-400A](https://openairdocs.org/model/hawker-siddeley-bh-125-400a): 2 aircraft (airframe model)
- [Hawker Siddeley DH.125-3A/RA](https://openairdocs.org/model/hawker-siddeley-dh-125-3a-ra): 2 aircraft (airframe model)
- [Raytheon HS 125-700A](https://openairdocs.org/model/raytheon-hs-125-700a): 1 aircraft (airframe model)

All 5 models: https://openairdocs.org/ad/85-07-08/models.md
Every aircraft: https://openairdocs.org/ad/85-07-08/aircraft.md

Its text cites no advisory circulars or STCs.

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