73-22-02 AIRCRAFT PARTS and DEVELOPMENT CORP.: Amendment 39-1737. Applies to Models A-9, A- 9A, and A-9B.
Compliance required within the next 100 hours' time in service after the effective date of this AD, unless already accomplished.
To prevent water accumulation in the wing lift struts and associated detrimental effects, accomplish the following:
(a) Inspect visually for welds on both sides of the four wing lift struts at the P/N 10671 eye fittings. A 360 degree fillet weld is required around the eye fitting shank on both sides of the lift strut to seal the strut against moisture. These fittings provide for attachment of the lift struts to the stabilizing struts.
(b) If the welds between the eye fittings and the lift struts do not provide a complete seal as specified above, the lift strut should be removed and checked for water ingestion visually and for corrosion by x-ray, ultrasonic or equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA, Southwest Region.
(1) If no water or corrosion is present in the strut, weld the eye fitting to the strut 360 degrees on both sides of the strut and reinstall the strut.
(2) If water is present in the strut (without corrosion), dry the strut, flush with linseed oil, weld the eye fitting to the strut 360 degrees on both sides of the strut and reinstall the strut.
(3) If corrosion is found, before further flight, the affected lift strut must be replaced or corrosion must be removed in accordance with a procedure approved by the Chief, Engineering and Manufacturing Branch, FAA, Southwest Region.
(c) If the welds between the eye fittings and the lift struts provide a complete seal as specified above, no further action is required.
(APDC Service Bulletin No. A-23 covers this same subject.)
This amendment becomes effective November 20, 1973.