74-24-04 LOCKHEED: Amendment 39-2015. Applies to all Model 382 series airplanes, Serial Numbers 3946 and 4101 through 4298, certificated in all categories, except those airplanes which have been modified in accordance with STC ST441SO, or equivalent.
Compliance required within the next 200 hours' time in service after the effective date of this AD, unless already accomplished.
To prevent cracks in the lower center wing section, modify the wing in accordance with Lockheed Service Bulletin 382-121, or later FAA approved revision, or an equivalent approved by the Chief, Engineering and Manufacturing Branch, FAA, Southern Region.
This amendment becomes effective November 20, 1974.