# AD 51-20-01: Cockpit Light

- Type: Airworthiness directive
- Status: Current
- Products: Airlift International C-46A, C-46D, C-46F, C-46R, C-46E, C-46A, C-46D, C-46E, C-46F, C-46A, C-46D, C-46F and 3 more
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Registered aircraft: 7 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/448C6AED728D938186256CC4006AEC7B.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/51-20-01

## The airworthiness directive

51-20-01 CURTISS-WRIGHT Applies to Model C-46 Series aircraft equipped with C-4 Cockpit Light Assembly.

Compliance required within 100 hours' time in service after the effective date of this amendment unless already accomplished.

To eliminate an electrical fire hazard existing in the pilot's compartment, the following rework must be accomplished:

1. Rework the C-4 cockpit light rheostat assembly in accordance with Figure 2. Fabricate insulator strip per Figure 2(a), and install as shown in Figure 2(b).

SECTIONAL VIEW OF COCKPIT LIGHT CASE - TYPE C-4A & C-4, WITH RHEOSTAT INSULATOR INSTALLED FIGURE 2

(U.S.A.F.T.O. No. 03-5G-12, dated September 8, 1950, covers this same subject.)

2. Revise the wiring to the C-4 lamp assembly as shown in Figure 3.

(Page 410D, Figure 301B of AN 01-25L-2 covers this same subject.)

Revised December 28, 1964.

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 2A5](https://openairdocs.org/tcds/2A5): Tempo Design Corporation; names 2 of 2 models: C-46/CW20-T, Super C-46/CW20-T
- [TCDS 3A2](https://openairdocs.org/tcds/3A2): Airlift International Inc.; names 1 of 4 models: C-46R

## 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: 7 (7 by airframe model, 0 by engine model)
- Makers: Curtiss Wright 7

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)
- [Curtiss Wright C-46R](https://openairdocs.org/model/curtiss-wright-c-46r): 1 aircraft (airframe model)

All 4 models: https://openairdocs.org/ad/51-20-01/models.md
Every aircraft: https://openairdocs.org/ad/51-20-01/aircraft.md

Its text cites no advisory circulars or STCs.

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