# AD 65-11-01: Instrument Static System

- Type: Airworthiness directive
- Status: Current
- Products: Textron 23
- Effective: June 19, 1965
- Published: May 20, 1965
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-67
- Registered aircraft: 147 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/9AF85B781323CB6086256A080071A7A2.0001
- DRS record last changed: January 21, 2026
- Page: https://openairdocs.org/ad/65-11-01

## The airworthiness directive

65-11-01 BEECH: Amdt. 39-67 Part 39 Federal Register May 20, 1965. Applies to Model 23 Aircraft Serial Numbers M-1 through M-334 except M-62.

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

To prevent water from entering the static lines through the fuselage static air ports and causing a system malfunction, accomplish the following or an FAA-approved equivalent:

  (a) Remove the tee fitting from the static line connection just aft of the rear cabin bulkhead.

  (b) Connect a 52-inch length of 0.25-inch O.D. by 0.040-inch wall polyethylene tubing to the static line running under the floorboard with a 262-P-1/4 union.

  (c) Place the pack nut and plastic ferrule not used with the union on the other end of the tubing and connect the tee fitting.

  (d) Remove the clips which originally secured the static lines to the cabin bulkhead and use one to attach the static line to the top of the bulkhead just aft of the cabin bulkhead Station 239.00.

  (e) Shorten the tubing from each static port to provide gentle curves and to prevent any low places in the line that could trap water between the static ports and the tee. Reconnect the two shortened static port lines to the tee fitting using either the original plastic ferrules and pack nuts or new like parts.

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

This directive effective June 19, 1965.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A1CE](https://openairdocs.org/tcds/A1CE): Textron Aviation Inc.; names 1 of 14 models: 23

## 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: 147 (147 by airframe model, 0 by engine model)
- Makers: Beech 147

Models with the most aircraft:

- [Beech 23](https://openairdocs.org/model/beech-23): 147 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/65-11-01/models.md
Every aircraft: https://openairdocs.org/ad/65-11-01/aircraft.md

Its text cites no advisory circulars or STCs.

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