1AD/DHC-1/14 - Flap Hinge Arms - Inspection and Modification

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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De Havilland DHC-1 (Chipmunk) Series Aeroplanes

AD/DHC-1/14 Flap Hinge Arms - Inspection and Modification

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Applicability: All models. Requirement: 1. Inspecting:

(a) Remove the flap centre hinge arms (P/N C1.W.353 and C1.W.354) and inspect internally for the presence of corrosion.

(b) Hinge arms in which small areas of shallow surface corrosion are present shall be cleaned internally by sand blasting (or other effective means) and coated with a suitable protective medium before further flight.

(c) Hinge arms corroded in excess of the limits specified above shall be replaced with serviceable items before further flight.

Note: The internal inspection can be performed readily by inserting a 1/8 inch diameter intrascope or similar optical aid, through on of the 3/8 inch diameter holes in the base plate of the hinge arm. The hole may be elongated slightly to allow the probe of the intrascope to be inserted to the full depth of the hinge arm.

2. Modification: Drill a 1/8 inch diameter drain hole in the lower surface of the hinge arm at a distance of 0.75 inch from the ball race centreline.

Compliance: Inspection - At intervals not exceeding 12 months. Modification - Forthwith.