Airworthiness Directive · Amendment 39-22972 · Doors
Schempp-Hirth Flugzeugbau GmbH Gliders
This AD applies to Schempp-Hirth Flugzeugbau GmbH Model Duo Discus gliders serial numbers (S/Ns) 1 through 422 (inclusive) and Duo Discus T gliders S/Ns 1 through 96 (inclusive), certificated in any category.
The FAA is adopting a new airworthiness directive (AD) for certain Schempp-Hirth Flugzeugbau GmbH Model Duo Discus and Duo Discus T gliders. This AD was prompted by reports of gliders' canopies opening during air tow. This AD requires modifying the canopy locking mechanism. The FAA is issuing this AD to address the unsafe condition on these products.
Within 12 months after the effective date of this AD, modify the canopy locking mechanism by installing a compression spring in the canopy locking mechanism, installing spring washers at the canopy actuating levers, modifying the front actuating lever to include a magnet and applying a red mark to the front and aft inside the left canopy frame; or installing a front actuating lever that has a magnet, in accordance with the applicable technical note specified in paragraph (g)(1) or (2) of this AD.
(1) For Model Duo Discus gliders: Appendix to Technical Note No. 380-1/396-6 attached to Schempp-Hirth Flugzeugbau GmbH Technical Note No. 380-1, No. 396-6 dated July 27, 2004 (issued as one document).
(2) For Model Duo Discus T gliders: Appendix to Technical Note No. 868-4/890-5 attached to Schempp-Hirth Flugzeugbau GmbH Technical Note No. 868-4, No. 890-5 dated February 23, 2005 (issued as one document).
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
