# AD 73-01-02: Alternate Air System

- Type: Airworthiness directive
- Status: Current
- Products: Cessna 310N, 310P and 310Q
- Effective: January 5, 1973
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-1579
- Registered aircraft: 393 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/5E2A015D18B96EEE86256A34006373BC.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/73-01-02

## The airworthiness directive

73-01-02 CESSNA: Amdt. 39-1579. Applies to Model 310N (Serial Numbers 310N0001 thru 310N0198), Model 310P (Serial Numbers 310P0001 thru 310P0240), and Model 310Q (Serial Numbers 310Q0001 thru 310Q0130) airplanes.

NOTE: This AD is not applicable to Model T310 airplanes which fall within these serial number ranges.

Compliance: Required as indicated, unless already accomplished.

To prevent moisture from possibly entering the alternate air system and freezing on powerplant induction system components when operating in below freezing temperatures, accomplish the following:

Within 50 hours' time in service after the effective date of this AD, install deflector baffles over the alternate air inlet in the vertical baffle and enlarge the warm air cut out in the induction air canister in accordance with Cessna Service Letter ME70-43 and Service Kit SK310-82D, or any other method approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region.

Thisamendment becomes effective January 5, 1973.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 3A10](https://openairdocs.org/tcds/3A10): Textron Aviation Inc.; names 3 of 23 models: 310P, 310Q, 310N

## 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: 393 (393 by airframe model, 0 by engine model)
- Makers: Cessna 393

Models with the most aircraft:

- [Cessna 310Q](https://openairdocs.org/model/cessna-310q): 277 aircraft (airframe model)
- [Cessna 310P](https://openairdocs.org/model/cessna-310p): 61 aircraft (airframe model)
- [Cessna 310N](https://openairdocs.org/model/cessna-310n): 55 aircraft (airframe model)

All 3 models: https://openairdocs.org/ad/73-01-02/models.md
Every aircraft: https://openairdocs.org/ad/73-01-02/aircraft.md

Its text cites no advisory circulars or STCs.

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