# AD 55-25-03: Earth Post Corrosion

- Type: Airworthiness directive
- Status: Current
- Products: de Havilland Aircraft Co., Ltd., The D.H. 104 Dove Series 1A, D.H. 104 Dove Series 2A, D.H. 104 Dove Series 5A, D.H. 104 Dove Series 5BA, D.H. 104 Dove Series 6A, D.H. 104 Dove Series 6BA, D.H. 104 Dove Series 7A, D.H. 104 Dove Series 7AXC, D.H. 104 Dove Series 8A and D.H. 104 Dove Series 8AXC
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 3 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/3C0785447CE9B59286256A34006BAD52.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/55-25-03

## The airworthiness directive

55-25-03 de HAVILLAND: Applies to All Model 104 "Dove" Aircraft.

Compliance required as soon as practical but not later than February 15, 1956, unless already accomplished.

A case has recently occurred where the presence of corrosion at the main earth connection, situated on the fuselage nose decking in the vicinity of nose frame 4, has reduced the efficiency of this earthling point sufficiently to cause overheating of the cockpit lighting cables.

The de Havilland Service strongly recommends that the following inspection be carried out at the earliest opportunity in order to ascertain the condition of this connection with which the FAA concurs and considers mandatory.

Method. 1. Examine earth post situated in nose floor, and ascertain if it has a protective coating of blue oil base paint D.T.D. 827. (If it is protected, do not disturb unless it appears to be in a bad condition.)

2. If no protection is evident, dismantle terminal, clear floor surface locally at the terminal with a stiff bristle brush, to ensure removal of any corrosion and to provide good electrical contact between mating faces of terminal assembly. Reassemble terminal, using corrosion washers D.H.S. 439 G in place of lead plated brass washer 4F.781. All other mating surfaces must be clean and free from corrosion. If steel washer shows signs of deterioration, it must be replaced by another one, cadmium plated. Completed assembly must be painted liberally with blue oil base paint D.T.D. 827 to prevent ingress of moisture.

(de Havilland Technical News Sheet CT (104), No. 121, Issue 2, dated July 14, 1955, also covers this same subject.)

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-807](https://openairdocs.org/tcds/A-807): Acro Aeronautical Services Ltd; names 10 of 10 models: D.H. 104 Dove Series 8A, D.H. 104 Dove Series 7A, D.H. 104 Dove Series 1A, D.H. 104 Dove Series 5A, D.H. 104 Dove Series 7AXC, D.H. 104 Dove Series 8AXC, D.H. 104 Dove Series 2A, D.H. 104 Dove Series 5BA…

## 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: 3 (3 by airframe model, 0 by engine model)
- Makers: Dehavilland 3

Models with the most aircraft:

- [Dehavilland DH104 DOVE 6A](https://openairdocs.org/model/dehavilland-dh104-dove-6a): 3 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/55-25-03/models.md
Every aircraft: https://openairdocs.org/ad/55-25-03/aircraft.md

Its text cites no advisory circulars or STCs.

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