Aircraft
Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration
CE-08-07
November 26, 2007
This is information only. Recommendations
aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin informs you of an
airworthiness concern regarding the canopy locking mechanism for the
following Schempp-Hirth sailplane models: Duo Discus, serial numbers 1
through 422; and Nimbus-4D, serial numbers 1 through 11.
Background
One of the above-referenced sailplanes experienced fuselage
deformation resulting from acceleration, which perhaps lowered the
friction in the canopy locking mechanism. It may then be possible for
the canopy locking mechanism to move into the open position. In another
case, the canopy opened shortly after takeoff on aerotow.
Neither the European Aviation Safety Agency (EASA), which is the
Technical Agent for the Member States of the European Community, nor
the German aviation authority, Luftfahrt-Bundesamt have issued an
airworthiness directive (AD) for those sailplanes registered for
operation in Europe. However, Schempp-Hirth has issued Technical Note
No. 380-1 / 396-6, dated July 2, 2004, to address this condition.
At this time, this airworthiness concern is not an unsafe condition
that would warrant AD action under Title 14 of the Code of Federal
Aviation Regulations (14 CFR) part 39.
Recommendations
We recommend all owners and operators comply with actions outlined
in Schempp-Hirth Technical Note No. 380-1 / 396-6, dated July 2, 2004.