COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Schweizer (Grumman) G-164 (Ag-Cat) Series Aeroplanes
AD/G164/15
Amdt 1
Rudder Main Spar 4/94
Applicability: Model G-164 with serial numbers 1 through 400.
Model G-164A with serial numbers 401 through 1674. Model G-164B with serial numbers 1B through 79B.
Requirement: 1. Action in accordance with Grumman Service Bulletin 61.
2. Visually inspect the interior and exterior of the rudder main tubular spar for corrosion.
Note: The hole fabricated through the bottom of the rudder fitting during compliance with SB 61, is required to be sealed after the spar is inspected and corrosion inhibited.
Compliance: 1. Unless already accomplished, prior to 30 June 1994.
2. (a) For aircraft operating in a salt water environment:
Prior to 31 March 1995, and thereafter at intervals not to exceed one calendar year.
2. (b) For all other aircraft:
Prior to 31 March 1995, and thereafter at intervals not to exceed three calendar years.
Background: The manufacturer received reports of significant corrosion on the main tubular spar of the rudder assembly. Amendment 1 is issued to introduce a calendar time compliance in lieu of operating time, a separate compliance for aircraft that are operating in a severe corrosive environment, and an additional internal inspection of the spar for corrosion in response to a local report of a rudder main spar failure that was precipitated by internal corrosion.