# AD 59-07-02: Auxiliary Hydraulic Pump

- Type: Airworthiness directive
- Status: Current
- Products: L. B. Smith C-46A, C-46D and C-46F
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Registered aircraft: 6 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/1F40C4359EDC2A9E862569A7007566AC.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/59-07-02

## The airworthiness directive

59-07-02 CURTISS-WRIGHT: Applies to all L.B. Smith C46/CW20-T aircraft not having this modification incorporated.

To be accomplished not later than August 1, 1959.

Service experience has indicated that the auxiliary hydraulic pump is unsatisfactory for use in compliance with the minimum gear retraction time.

To provide reliable continuous hydraulic pressure during landing gear retraction, the auxiliary hydraulic pump and motor must be removed from the hydraulic system and replaced by a hydraulic by-pass system in accordance with L. B. Smith Aircraft Corporation Report No. RX5.130.01 dated April 16, 1958, or an equivalent system. Airplane Flight Manual Revision, dated July 11, 1958, is required with this modification.

(L. B. Smith Service Modification No. SM20T-6 dated June 23, 1958, covers this same subject.)

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-789](https://openairdocs.org/tcds/A-789): L. B. Smith Aircraft Corporation; names 3 of 3 models: C-46D, C-46F, C-46A

## 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: 6 (6 by airframe model, 0 by engine model)
- Makers: Curtiss Wright 6

Models with the most aircraft:

- [Curtiss Wright C-46F](https://openairdocs.org/model/curtiss-wright-c-46f): 4 aircraft (airframe model)
- [Curtiss Wright C-46A](https://openairdocs.org/model/curtiss-wright-c-46a): 1 aircraft (airframe model)
- [Curtiss Wright C-46D](https://openairdocs.org/model/curtiss-wright-c-46d): 1 aircraft (airframe model)

All 3 models: https://openairdocs.org/ad/59-07-02/models.md
Every aircraft: https://openairdocs.org/ad/59-07-02/aircraft.md

Its text cites no advisory circulars or STCs.

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