# AD 71-05-03: Known Icing Conditions

- Type: Airworthiness directive
- Status: Current
- Products: Textron 99, 99A, 99A (FACH), A60, A99, A99A, B99 and C99
- Effective: July 16, 1971
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-1244
- Registered aircraft: 138 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/4CEF76645500908F86256E01005AD064.0001
- DRS record last changed: January 21, 2026
- Page: https://openairdocs.org/ad/71-05-03

## The airworthiness directive

71-05-03 BEECH: Amendment 39-1159 as amended by Amendment 39-1222 is further amended by Amendment 39-1244. Applies to Models A60 (Serial Numbers P123, P127 through P167), and all 99 series airplanes (Serial Numbers U-1 through U-136) approved for flight into known icing conditions.

Compliance: Required as indicated, unless already accomplished.

To prevent operation under unsafe environmental conditions, accomplish the following:

A) Effective immediately, operation of the airplane in known icing conditions is prohibited.

B) Prior to further flight, modify the existing operating limitations placard located on the righthand side wall adjacent to the copilot oxygen outlet on Beech Model A60 airplanes and located on the overhead panel on all Beech 99 series airplanes to read as follows:

THIS AIRPLANE IS NOT APPROVED FOR FLIGHT IN KNOWN ICING CONDITIONS.

C) On Beech Models A60 airplanes, install either transducer unit, P/N 3E1793, P/N 190-1, or P/N 190-2 in accordance with Beech Service Instruction 0430-355, Rev. 1, or by the accomplishment of any equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region.

D) On all Beech 99 series airplanes, install transducer unit P/N 795-1 in accordance with Beechcraft Service Instructions No. 0378-355, or by the accomplishment of any equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region.

E) Upon accomplishment of the modifications provided in Paragraphs C or D, compliance with the provisions of Paragraphs A and B is no longer required.

NOTE: The Airplane Flight Manuals and Type Certificate Data Sheets for these model airplanes will be amended to reflect these changes.

Amendment 39-1159 became effective March 2, 1971.

Amendment 39-1222 became effective June 3, 1971.

This Amendment 39-1244 becomes effective July 16, 1971.

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A14CE](https://openairdocs.org/tcds/A14CE): Textron Aviation Inc.; names 6 of 12 models: A99, A99A, C99, B99, 99A, 99
- [TCDS A12CE](https://openairdocs.org/tcds/A12CE): Textron Aviation Inc.; names 1 of 3 models: A60

## 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: 138 (138 by airframe model, 0 by engine model)
- Makers: Beech 138

Models with the most aircraft:

- [Beech C-99](https://openairdocs.org/model/beech-c-99): 54 aircraft (airframe model)
- [Beech A60](https://openairdocs.org/model/beech-a60): 43 aircraft (airframe model)
- [Beech 99](https://openairdocs.org/model/beech-99): 23 aircraft (airframe model)
- [Beech 99A](https://openairdocs.org/model/beech-99a): 11 aircraft (airframe model)
- [Beech B-99](https://openairdocs.org/model/beech-b-99): 6 aircraft (airframe model)
- [Beech A99](https://openairdocs.org/model/beech-a99): 1 aircraft (airframe model)

All 6 models: https://openairdocs.org/ad/71-05-03/models.md
Every aircraft: https://openairdocs.org/ad/71-05-03/aircraft.md

Its text cites no advisory circulars or STCs.

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