# AD 84-20-05: Landing Gear and Brakes

- 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: October 14, 1984
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-4910
- Registered aircraft: 26 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/7396C15123ECBAC3862569F3004C24D8.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/84-20-05

## The airworthiness directive

84-20-05 BRITISH AEROSPACE: Amendment 39-4910. Applies to Model DH/HS/BH 125 airplanes, series and serial numbers listed in the Planning Information section of the service bulletins referenced below, certificated in all categories. Compliance is required as indicated, unless previously accomplished.

To prevent landing gear and brake failure, within the next 90 days after the effective date of this AD, accomplish the following:

A. Incorporate British Aerospace modification No. 251714 to the landing gear emergency selector shaft assembly in accordance with the instructions of British Aerospace HS 125 Service Bulletin 32-59-(1714), Revision 3, dated June 23, 1983.

B. Replace the knife edges of the brake control valves that have been overhauled by Dunlop Aviation Incorporated (California), with new parts in accordance with the instructions of British Aerospace HS 125 Service Bulletin 32-193, Revision 1, dated July 26, 1983.

C. Inspect the main landing gear jacks forcracks, and replace the jacks if necessary, in accordance with the instructions of British Aerospace HS 125 Service Bulletin 32-A197, dated August 29, 1983.

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

E. 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.

This amendment becomes effective October 14, 1984.

## 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/84-20-05/models.md
Every aircraft: https://openairdocs.org/ad/84-20-05/aircraft.md

Its text cites no advisory circulars or STCs.

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