64-04-05: Outer Wing Panel

64-04-05 NAVION: Amdt. 684 Part 507 Federal Register February 11, 1964. Applies to All Navion D, E, F, and G Aircraft, Serial Numbers NAV-4-2 and up. Compliance required within 10 hours' time in service after the effective date of this AD and thereafter within every 100 hours'-time in service. (a) Visually inspect wing panel outboard of Wing Stations 130 (outboard edge of flap) for loose rivets. Replace loose rivets with the next larger size. Where this is impractical due to edge distance, interference, etc., install a protruding head rivet of the same diameter located between the loose rivet and the next adjacent rivet. (b) Install 4 AD 4 protruding head rivets both top and bottom skin equally spaced between the last 5 rivets in stringer No. 3. This is at the front tip tank attachment. (c) This inspection is no longer necessary if the skin with flush rivets is replaced with new skin of equivalent strength and protruding head rivets of the original size are used. Other modifications must be approved by a Regional FAA Engineering and Manufacturing Branch. (Navion Service Letter No. 85 covers this same subject.) This directive effective February 17, 1964.