# AD 53-12-02: Hydraulic Hand Pump Seals

- Type: Airworthiness directive
- Status: Current
- Products: Viking Air DHC-2 Mk.I, DHC-2 Mk.II and DHC-2 Mk.III
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 140 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/817D90AE52B3C19286256A34006B722A.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/53-12-02

## The airworthiness directive

53-12-02 de HAVILLAND: Applies to Model DHC-2 (Beaver) Aircraft, Serial Numbers 1 to 451 Inclusive.

Compliance required as indicated.

Cases have been reported of loss of seals in the flap hydraulic hand pump No. 430RDH. To prevent the above condition a modification (No. 2/926) was incorporated on production aircraft and should be incorporated on aircraft in service as soon as possible but not later than the next 100 hours.

The FAA concurs in this mandatory action by the Canadian Department of Transport.

(de Havilland Technical News Sheet, Series B, No. 63 dated March 19, 1953, available from de Havilland Aircraft of Canada, Ltd., Toronto, Ontario, Canada, covers this same subject and describes method of repair.)

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-806](https://openairdocs.org/tcds/A-806): De Havilland Aircraft of Canada Limited; names 3 of 3 models: DHC-2 Mk.II, DHC-2 Mk.III, DHC-2 Mk.I

## 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: 140 (140 by airframe model, 0 by engine model)
- Makers: Dehavilland 135, Dehavilland Acft Of Canada 3, Dehavilland-Shawano 2

Models with the most aircraft:

- [Dehavilland DHC-2 MK. I(L20A)](https://openairdocs.org/model/dehavilland-dhc-2-mk-i-l20a): 91 aircraft (airframe model)
- [Dehavilland DHC 2 MK III](https://openairdocs.org/model/dehavilland-dhc-2-mk-iii): 24 aircraft (airframe model)
- [Dehavilland DHC-2 MK.I](https://openairdocs.org/model/dehavilland-dhc-2-mk-i): 20 aircraft (airframe model)
- [Dehavilland Acft Of Canada DHC-2 MK I](https://openairdocs.org/model/dehavilland-acft-of-canada-dhc-2-mk-i): 3 aircraft (airframe model)
- [Dehavilland-Shawano DHC-2 MK.I](https://openairdocs.org/model/dehavilland-shawano-dhc-2-mk-i): 2 aircraft (airframe model)

All 5 models: https://openairdocs.org/ad/53-12-02/models.md
Every aircraft: https://openairdocs.org/ad/53-12-02/aircraft.md

Its text cites no advisory circulars or STCs.

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