Summary
This document proposes to adopt a new airworthiness directive (AD) that would apply to certain Scheibe Flugzeugbau GmbH (Scheibe) SF34 and SF34B gliders. The proposed action would require adding armature (supportive covering) to both wings, modifying the root rib of the left wing, and incorporating changes and operating limitations to the flight manual. Failure of the left wing root rib on one of the affected gliders while in flight prompted the proposed action. The actions specified by the proposed AD are intended to prevent fatigue failure of the wing, which could result in loss of control of the glider.