69-11-07 SLINGSBY: Amdt. 39-771. Applies to all Slingsby Model T.53.B Gliders.
Before further flight after the effective date of this AD, modify the fuselage center section structure in accordance with Slingsby Technical Instruction No. 39, dated March 1969, or later ARB-approved issue or FAA-approved equivalent.
This amendment becomes effective June 2, 1969.