# AD 72-21-07: Longitudinal Stability

- Type: Airworthiness directive
- Status: Current
- Products: Piper PA-23-250 (Navy UO-1)
- Effective: April 29, 1976
- Published: April 26, 1976
- Issued: April 15, 1976
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-2586
- Registered aircraft: 899 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/63DA4FBB6166277B86256E1200498A14.0001
- DRS record last changed: November 21, 2025
- Page: https://openairdocs.org/ad/72-21-07

## The airworthiness directive

72-21-07 PIPER AIRCRAFT CORP: Amendment 39-1540 as amended by Amendment 39-2586. Applies to PA23-250 airplanes, S/Ns 27-4575 to 27-4587 inclusive, 27-4589 to 27- 4620 inclusive, 27-4622 to 27-4672 inclusive, 27-4674 to 27-4682 inclusive, and 27-4684 to 27- 4694 inclusive, and PA-23-250 airplanes which have been altered by substitution of Piper P/N 32958-00, Section Assembly - Fuselage, Nose, 34552-00, Section Assembly - Fuselage, Nose, or 33346-05, Radome Assembly for Piper P/N 30517-00, Section Assembly - Fuselage, Nose, or 30517-06, Section Assembly - Fuselage, Nose, certificated in all categories.

Compliance required within 30 days after the effective date of this AD, unless already accomplished.

To improve the longitudinal stability characteristics and to prevent longitudinal stick force reversal during certain flight conditions, accomplish the alteration contained in Piper Service Bulletin No. 345, dated 7 Oct. 1971; or an equivalent method approved by the Chief,Engineering and Manufacturing Branch, FAA Eastern Region.

Upon request through a maintenance inspector, accompanied by substantiating data, the compliance time specified in the AD may be increased by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.

Amendment 39-1540 was effective October 19, 1972.

This amendment 39-2586 is effective April 29, 1976.

## 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-23-250 (Navy UO-1)

## 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: 899 (899 by airframe model, 0 by engine model)
- Makers: Piper 899

Models with the most aircraft:

- [Piper PA-23-250](https://openairdocs.org/model/piper-pa-23-250): 894 aircraft (airframe model)
- [Piper PA-23-250 (6PCLM)](https://openairdocs.org/model/piper-pa-23-250-6pclm): 5 aircraft (airframe model)

All 2 models: https://openairdocs.org/ad/72-21-07/models.md
Every aircraft: https://openairdocs.org/ad/72-21-07/aircraft.md

Its text cites no advisory circulars or STCs.

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