# AD 72-18-01: Fuel Selector Valve Warning Light

- Type: Airworthiness directive
- Status: Current
- Products: Textron 35, A35, B35 and C35
- Effective: August 29, 1972
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-1505
- Registered aircraft: 831 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/C7D27683532EB43386256A0800733FC7.0001
- DRS record last changed: January 21, 2026
- Page: https://openairdocs.org/ad/72-18-01

## The airworthiness directive

72-18-01 BEECH: Amdt. 39-1505. Applies to Models 35, A35, B35 and C35 airplanes (Serial Numbers D-1 through D-2900) with a P/N 35-924065 fuel unit modified by the installation of Beech Kit No. 35-5030S (Serial Numbers 100 through 989) or any equivalent installation using a warning light with a dimming feature. (NOTE: Installation of either Beech Kit No. 35-5030S or P/N 35-924230 fuel unit is required by AD 69-18-01.)

To prevent dimming of fuel selector valve disengagement warning light, unless already accomplished, accomplish the following:

A) Effective immediately until Paragraph B has been accomplished, adjust the dimming lens on the fuel selector valve disengagement warning light to maximum bright.

B) Within the next 25 hours' time in service after the effective date of this AD, either replace MS 25041-2 light indicator assembly with MS 25041-6 light indicator assembly or replace the dimming lens assembly of the MS 25041-2 light assembly with the non-dimming lens assembly from an MS 25041-6 light assembly. Any equivalent method of compliance must be submitted to and approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region.

This amendment becomes effective August 29, 1972.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-777](https://openairdocs.org/tcds/A-777): Textron Aviation Inc.; names 4 of 9 models: A35, B35, C35, 35

## 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: 831 (831 by airframe model, 0 by engine model)
- Makers: Beech 831

Models with the most aircraft:

- [Beech 35](https://openairdocs.org/model/beech-35): 266 aircraft (airframe model)
- [Beech C35](https://openairdocs.org/model/beech-c35): 258 aircraft (airframe model)
- [Beech A35](https://openairdocs.org/model/beech-a35): 159 aircraft (airframe model)
- [Beech B35](https://openairdocs.org/model/beech-b35): 148 aircraft (airframe model)

All 4 models: https://openairdocs.org/ad/72-18-01/models.md
Every aircraft: https://openairdocs.org/ad/72-18-01/aircraft.md

Its text cites no advisory circulars or STCs.

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