Aircraft
Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration
CE-07-32
April 26, 2007
This is information only. Recommendations
aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin informs you of an
airworthiness concern of all variants of DG Flugzeugbau Model DG 300
sailplanes. The European Aviation Safety Agency (EASA) issued emergency
airworthiness directive (AD) number 2007-0100-E, dated April 12, 2007,
and corrected April 13, 2007, for those sailplanes registered for
operation in Europe. That AD is based on DG Flugzeugbau Technical Note
No. 359/24, which was EASA approved on April 11, 2007.
Background
During the execution of a major repair on a DG 300 sailplane, a
manufacturing defect in the wing spar caps was found. Severe undulation
of the glass fiber rovings have resulted in EASA issuing the
above-referenced AD, which requires an immediate reduction in the
operating limitations until further notice. With these undulations, an
adequate factor of safety during full operation is not ensured.
Strength tests have been performed with the undulations resulting in
determined reductions of the operating limitations that enable safe
operation of all DG 300’s without repair of the spar caps.
These sailplanes are not type certificated in the United States and,
therefore, the condition is not addressed by FAA AD action. However,
these sailplanes could be operating in the United States with an
experimental airworthiness certificate or other means.
Recommendations
We recommend any DG 300 sailplane operating in the United States
have the actions outlined in DG Flugzeugbau Technical Note No. 359/24
incorporated.