# AD 81-15-05: Engine and Airplane Modifications

- Type: Airworthiness directive
- Status: Current
- Products: Cessna P210N
- Effective: July 27, 1981
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-4168
- Registered aircraft: 421 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/0DC590F8EB88CFE0862569B9004D391D.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/81-15-05

## The airworthiness directive

81-15-05 CESSNA: Amendment 39-4168. Applies to Model P210N (Serial Numbers P21000001 through P2100069O) airplanes certificated in any category.

COMPLIANCE: Required as indicated unless already accomplished.

To further reduce the possibility of engine detonation and improve the airplane climb performance within the next 100 hours time-in-service after the effective date of this AD, accomplish the following:

A) Perform the engine and airplane modifications in accordance with Cessna Single- Engine Customer Care Service Information Letter SE81-35 dated May 29, 1981, and SE81-35 Supplement # 1 dated June 29, 1981.

B) Install the cabin pressurization sonic nozzle identified as Cessna Assembly Part Number 2150001-11 in accordance with the aircraft service manual.

NOTE: This part, previously required by Airworthiness Directive (AD) 81-01- 04, was installed on all airplanes manufactured subsequent to the airplane serial numbers included in AD 81-01-04.

C) Airplanes may be flown in accordance with FAR 21.197 to a location where this AD may be accomplished.

D) Any equivalent method of compliance with this Airworthiness Directive must be approved by the Chief, Aircraft Certification Program Office, FAA Central Region, Room 238, Mid-Continent Airport, Wichita, Kansas 67209; telephone (316) 942-4285.

Cessna Single-Engine Customer Care Service Letter SE81-35, applicable to this AD, recommends compliance by November 1, 1981.

This AD supersedes AD 81-01-04, Amendment 39-4007.

This amendment becomes effective July 27, 1981.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 3A21](https://openairdocs.org/tcds/3A21): Textron Aviation Inc.; names 1 of 28 models: P210N

## 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: 421 (421 by airframe model, 0 by engine model)
- Makers: Cessna 421

Models with the most aircraft:

- [Cessna P210N](https://openairdocs.org/model/cessna-p210n): 421 aircraft (airframe model)

All 2 models: https://openairdocs.org/ad/81-15-05/models.md
Every aircraft: https://openairdocs.org/ad/81-15-05/aircraft.md

Its text cites no advisory circulars or STCs.

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