AD/RAD/37 Narco VHF Nav Obs Gear Assembly Modification Cancelled (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive AD/RAD/37.

Radio Communication and Navigation Equipment

AD/RAD/37 Narco VHF NAV OBS
Gear Assembly - Modification 4/2009

Requirement:

CANCELLED.

This AD is cancelled on 9 April 2009.

Background:

This unique Australian AD was raised in 1978 against Narco Avionics Service Bulletin (SB) - centreline Nav. No. 6 requiring a modification of Narco Nav receivers type Nav-121, 122,122A and indicators type ID-124 to prevent slippage between gears of centreline Nav. OBS potentiometers and azimuth cards.

Compliance was within 100 hours TIS after 30 September 1978.

Given the extended period this AD has been promulgated, and that affected Nav receivers would have been modified by now, this AD is considered to be no longer required.

James Coyne
Delegate of the Civil Aviation Safety Authority

24 February 2009