# AD 47-34-02: Tail Cone Drain Holes

- Type: Airworthiness directive
- Status: Current
- Products: Textron D18C, D18C-T and D18S
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 55 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/CF0CE4255D2950CF86256A1C0072E995.0001
- DRS record last changed: January 21, 2026
- Page: https://openairdocs.org/ad/47-34-02

## The airworthiness directive

47-34-02 BEECH: (Was Mandatory Note 3 of AD-770-1 and Mandatory Note 4 of AD- 765-1.) Applies to D18S, D18C and D18C-T Airplanes Which Do Not Have Drain Provisions at Bulkhead No. 15.

Compliance required prior to December 1, 1947.

To provide additional drainage, to prevent freezing of trapped moisture in the tail cone which could jam the elevator control system, a 3/4-inch diameter hole should be drilled near the front of the tail cone outer section on the centerline of the lower surface. A suitable marine grommet should be installed to provide for negative pressures. Also a 1/2-inch diameter hole should be drilled on each side of the jack pad through the lower part of bulkhead No. 15.

(Beech Service Bulletin D18-46 covers this same subject.)

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-765](https://openairdocs.org/tcds/A-765): Textron Aviation Inc.; names 2 of 17 models: D18S, D18C
- [TCDS TC 770](https://openairdocs.org/tcds/TC%20770): Hawker Beechcraft Corporation; names 1 of 2 models: D18C-T

## 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: 55 (55 by airframe model, 0 by engine model)
- Makers: Beech 55

Models with the most aircraft:

- [Beech D18S](https://openairdocs.org/model/beech-d18s): 55 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/47-34-02/models.md
Every aircraft: https://openairdocs.org/ad/47-34-02/aircraft.md

Its text cites no advisory circulars or STCs.

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