# AD 66-14-02: Windshield Deicing Systems

- Type: Airworthiness directive
- Status: Current
- Products: Learjet 23 and 24
- Effective: June 1, 1966
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-242
- Registered aircraft: 13 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/ABBC64C8FF16B63086256D500042A173.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/66-14-02

## The airworthiness directive

66-14-02 LEARJET: Amdt. 39-242 Part 39 Federal Register June 1, 1966. Applies to Models 23 and 24 Airplanes.

Compliance required as indicated, unless already accomplished.

  (a) On Model 23 airplanes, before further flight remove windshield deicing alcohol cans.

  (b) On Model 23 airplanes, the following applies to all Serial Numbers except 003, 011, 016, 020, 024, 026, 033, 035, 039, 043, 044, 047, 050, 051, 062, 065A, 069, 070, 072, 073, 074, 075, 076, 077, 078, 079, 080, 081, 082, 083, 087, 090, 092, 093: further flight is limited to day VFR meteorological conditions and to flight levels below 240 until installation of an attitude indicator (gyro horizon) usable by the pilot and powered by a source separate from the airplane's primary electrical system.

  (c) Modify the electrical system on Model 23 airplanes, and on Model 24 airplanes S/N 24-100 through 24-129, in accordance with Lear Jet Engineering Change Record No. 340, 227, 230 or 233 (as applicable) or equivalent data approved by the Chief, Engineering and Manufacturing Branch, Central Region within the next 550 hours' time in service after the effective date of this AD. The affected airplanes and applicable data are as follows:

  (1) Serial Numbers 23-012 and 23-031, Engineering Change Record No. 340.

  (2) Serial Numbers 23-003 through 23-011, 23-013 through 23-030, and 23- 032 through 23-099, Engineering Change Record No. 340, 227, 230, 233.

  (3) Serial Numbers 24-100 through 24-129, Engineering Change Record No. 340.

This directive effective upon publication in the Federal Register for all persons except those to whom it was made effective immediately by telegram dated May 21, 1966.

Revised August 4, 1966.

Revised November 22, 1966.

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A10CE](https://openairdocs.org/tcds/A10CE): Learjet Inc.; names 1 of 29 models: 24
- [TCDS A5CE](https://openairdocs.org/tcds/A5CE): Learjet Inc.; names 1 of 1 models: 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: 13 (13 by airframe model, 0 by engine model)
- Makers: Learjet 13

Models with the most aircraft:

- [Learjet 24](https://openairdocs.org/model/learjet-24): 7 aircraft (airframe model)
- [Learjet 23](https://openairdocs.org/model/learjet-23): 6 aircraft (airframe model)

All 2 models: https://openairdocs.org/ad/66-14-02/models.md
Every aircraft: https://openairdocs.org/ad/66-14-02/aircraft.md

Its text cites no advisory circulars or STCs.

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