AD/INST/25 Aerosonic Encoding Altimeters Replacement 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/INST/25.

Instruments and Automatic Pilots

AD/INST/25 Aerosonic Encoding
Altimeters - Replacement 3/2009

Requirement:

CANCELLED.

This AD is cancelled on 12 March 2009.

Background:

This unique Australian AD raised in 1978 required replacement of series 1014 Aerosonic Encoding Altimeters having serial numbers other than 26320C to 28921C.  Requirement also contained in Piper Service Bulletin (SB) SB No. 600-67.  Replacement required following manufacturer notification that Encoding Altimeters (series 1014) had been found to read approximately 100 feet high after a warm-up period of approximately 15 minutes.

Compliance was within 100 hours TIS after 30 April 1978.

Given the extended period this AD has been promulgated, and that the cost of replacement of Encoding Altimeters units was borne by Aerosonic and would have been replaced by now, this AD is considered to be no longer required.

James Coyne
Delegate of the Civil Aviation Safety Authority

27 January 2009