1AD/PA-25/36 Amdt 3 - Fuselage Wing Spar Attachment Fittings

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Piper PA-25 (Pawnee) Series Aeroplanes

AD/PA-25/36

Amdt 3

Fuselage Wing Spar Attachment Fittings 11/99

Applicability: PA-25 (PA-25-150 & PA-25-180), PA-25-235 and PA-25-260 aeroplanes all serial numbers.

Requirement: 1. Gain access to the forward wing spar to fuselage and aft wing spar to fuselage attachment fittings. Remove any cracked, flaking or bubbling paint and any chemical build up.

Perform a close detailed visual inspection of the front and rear fuselage tubular cluster wing attach fittings. Inspect for cracks, corrosion and general condition. Pay particular attention to the areas indicated in Figure 1.

2. Remove the wings from the aircraft. Thoroughly clean the forward wing spar fuselage attachment fitting. Carry out the following inspections:

(a) Visually inspect the forward fitting for corrosion and general condition. The bore of the lugs of the fitting should be particularly examined for evidence of corrosion occurring between the lug laminates.

(b) Perform a Magnetic Particle inspection of the forward fittings for cracks in accordance with CAO 108.8 using the magnetic flow technique. Pay particular attention to the areas indicated in Figure 1. Replace any cracked fittings.

Note 1: FAA AD 95-12-01 and FAA AD 93-21-12 refers.

Note 2: In assessing serviceability of a fitting after corrosion removal, consideration should be made of the possibility of corrosion between the laminates. In a number of cracked fittings provided to the Authority, interlaminate corrosion has been significant, even though it was not apparent in the bore of the fitting.

Note 3: Numerous proposals for repair by welding of cracked fittings have been received by CASA, the FAA and the manufacturer. Because of difficulties ensuring complete crack removal and alteration of the strength and fatigue properties of the fitting by welding, repair is not viable, and cracked fittings must be replaced.

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

SCHEDULE OF AIRWORTHINESS DIRECTIVES

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Compliance: 1. Inspect in accordance with Requirement 1 of this Directive within 100 hrs time in service or 900 landings whichever occurs first after 4 January 1996.

Re-inspect at intervals not exceeding 100 hours time in service or 900 landings, whichever occurs first.

2. Initially inspect in accordance with Requirement 2 of this Directive within 2000 hrs time in service of forward fitting installation or within 100 hrs time in service after 4 January 1996, whichever occurs last;