AD/PHZL/58 Piston Nut B474 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/PHZL/58.

Propellers - Variable Pitch - Hartzell

AD/PHZL/58 Piston Nut B474 4/2009

Requirement:

CANCELLED.

This AD is cancelled on 9 April 2009.

Background:

This unique Australian AD was raised in1989 against Hartzell Service Bulletin (SB) No. 163 requiring inspection and replacement of the B-474 nut of Hartzell Propeller HC-A6A-3 installed on SD3-60-300 aircraft due manufacturer advice that the nut may not fully contact the piston when correctly torqued which could cause an inadvertent blade angle change.

Compliance was:

Inspection: Within 100 hours TIS from 19 May 1989, or by 9 June 1989 whichever occurs first.  Thereafter re-inspect at intervals not exceeding 100 hours TIS until propeller is modified.

Modification: At next propeller overhaul or by 30 June 1991, whichever occurs first.

Given the extended period this AD has been promulgated, and that affected B-474 nuts would have been replaced by now, this AD is considered to be no longer required.

James Coyne
Delegate of the Civil Aviation Safety Authority

19 February 2009