61-13-03 SCHLEICHER: Amdt. 299 Part 507 Federal Register June 24, 1961. Applies to Model K7 Gliders With Serial Numbers Up To and Including 935 and Serial Number 984.
Compliance required prior to next flight unless already accomplished.
To preclude the buckling of fuselage steel tube members on each side at the rear of the fuselage, replacement of five tubes with tubes having greater wall thickness is required. Replace the existing steel tube diagonal members, counting forward from the tail post as follows, using Civil Aeronautics Manual 18 repair procedures or manufacturer's recommendation.
(a) Right side only, third member: Replace with 12 MMS. (15/32"), outside diameter, 1MM. (.040") wall thickness tubes.
(b) Right and left side, fourth and sixth members: Replace with 14 MMS. (9/16") outside diameter, 1 MM. (.040") wall thickness tubes.
(Schleicher Drawing No. L-211.10-A4 dated March 15, 1961, covers this subject.)
This directive effective June 24, 1961.