# AD 47-33-03: Tail Cone Drain Holes

- Type: Airworthiness directive
- Status: Current
- Products: Textron Army AT-11 and C18S
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 13 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/5FE50DEE780485B186256A1C00720DA7.0001
- DRS record last changed: January 21, 2026
- Page: https://openairdocs.org/ad/47-33-03

## The airworthiness directive

47-33-03 BEECH: (Was Mandatory Note 5 of AD-757-2 and Mandatory Note 4 of AD- 582-2.) Applies to AT-11 and C18S Aircraft.

To be accomplished prior to certification or, if certificated, on next periodic inspection but not later than November 1, 1947.

In order to provide better tail cone drainage, add two drain holes in the tail cone and two 1/4-inch drain holes in the fuselage bulkhead No. 15 as shown in Figure 2.

(Beech Service Bulletin No. C18-7 covers this same subject.)

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-2-582](https://openairdocs.org/tcds/A-2-582): Textron Aviation Inc.; names 1 of 2 models: Army AT-11
- [TCDS A-757](https://openairdocs.org/tcds/A-757): Textron Aviation Inc.; names 1 of 1 models: C18S

## 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: 13 (13 by airframe model, 0 by engine model)
- Makers: Beech 13

Models with the most aircraft:

- [Beech C18S](https://openairdocs.org/model/beech-c18s): 13 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/47-33-03/models.md
Every aircraft: https://openairdocs.org/ad/47-33-03/aircraft.md

Its text cites no advisory circulars or STCs.

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