# AD 81-24-02: Hydraulic System Fluid Flow

- Type: Airworthiness directive
- Status: Current
- Products: Gulfstream Aerospace G-1159 and G-1159A
- Effective: November 23, 1981
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-4259
- Registered aircraft: 73 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/1EC321902BEFB643862569F100678B55.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/81-24-02

## The airworthiness directive

81-24-02 GULFSTREAM AMERICAN CORPORATION (GRUMMAN AMERICAN AVIATION CORPORATION): Amendment 39-4259. Applies to Model G-1159 Serial Numbers 1 through 248, 250, 251, 253 through 258 and 775; Model G-1159A Serial Numbers 249, 252, 300 through 338 and 875.

Compliance required within the next 75 hours time in service after the effective date of this AD, unless already accomplished. To prevent the loss of fluid flow in the auxiliary hydraulic system following a complete loss of fluid in the combined hydraulic system, install a check valve in the reservoir system in accordance with Gulfstream American Aircraft Service Change (ASC) No. 295 (for the Model G-1159) and ASC No. 21 (for the Model G-1159A), both dated September 1, 1981. An equivalent method of compliance may be approved by the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration, Southern Region.

This amendment becomes effective November 23, 1981.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A12EA](https://openairdocs.org/tcds/A12EA): Gulfstream Aerospace Corporation; names 2 of 7 models: G-1159A, G-1159

## 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: 73 (73 by airframe model, 0 by engine model)
- Makers: Gulfstream Aerospace 32, Gulfstream American 29, Grumman 8, Grumman American Avn. 4

Models with the most aircraft:

- [Gulfstream Aerospace G-1159A](https://openairdocs.org/model/gulfstream-aerospace-g-1159a): 32 aircraft (airframe model)
- [Gulfstream American G-1159A](https://openairdocs.org/model/gulfstream-american-g-1159a): 27 aircraft (airframe model)
- [Grumman G-1159](https://openairdocs.org/model/grumman-g-1159): 8 aircraft (airframe model)
- [Grumman American Avn. G-1159](https://openairdocs.org/model/grumman-american-avn-g-1159): 4 aircraft (airframe model)
- [Gulfstream American G-1159](https://openairdocs.org/model/gulfstream-american-g-1159): 2 aircraft (airframe model)

All 5 models: https://openairdocs.org/ad/81-24-02/models.md
Every aircraft: https://openairdocs.org/ad/81-24-02/aircraft.md

Its text cites no advisory circulars or STCs.

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