# AD 55-13-01: Idler Bellcrank Installation

- Type: Airworthiness directive
- Status: Current
- Products: Piper PA-23
- Published: December 4, 1956
- Issued: December 4, 1956
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Registered aircraft: 155 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/13C4FCFA2DEBFAFC8625698B007648E7.0001
- DRS record last changed: November 21, 2025
- Page: https://openairdocs.org/ad/55-13-01

## The airworthiness directive

55-13-01 PIPER: Applies to Model PA-23, Serial Numbers 23-160 to 23-162 Inclusive, 23-166 to 23-168 Inclusive, 23-170, 23-172, 23-177, 23-193 to 23-219 Inclusive, 23-221 to 23- 224 Inclusive, 23-226 to 23-229 Inclusive, 23-231 to 23-234 Inclusive, and 23-237.

Compliance required by August 1, 1955.

It has been found that all the PA-23 Models listed above have installed two flexible fuel valve controls that have been found to flex excessively at the splice. The addition of an idler bellcrank should be accomplished by the use of Piper Kit No. 754 103 and the instructions included. Owners of PA-23's with auxiliary fuel tanks must not operate the auxiliary fuel system until this modification has been accomplished.

(Piper Immediate Action Service Bulletin No. 139 applies to this malfunction.)

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 1A10](https://openairdocs.org/tcds/1A10): Piper Aircraft Inc.; names 1 of 6 models: PA-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: 155 (155 by airframe model, 0 by engine model)
- Makers: Piper 155

Models with the most aircraft:

- [Piper PA-23](https://openairdocs.org/model/piper-pa-23): 155 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/55-13-01/models.md
Every aircraft: https://openairdocs.org/ad/55-13-01/aircraft.md

Its text cites no advisory circulars or STCs.

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