Aircraft
Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration
CE-10-26
April 14, 2010
This is information only. Recommendations
aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin informs you of and
airworthiness concern on Schempp-Hirth Models Nimbus-4M, Nimbus-4DM,
and Ventus 2cM powered sailplanes.
These sailplanes are not type certificated in the United States (U.S.)
and, therefore, the condition is not addressed by Federal Aviation
Administration Airworthiness Directive (AD) action. However, these
sailplanes could be operating in the U.S. with an experimental
airworthiness certificate or other means.
Background
On a Ventus-2cM, a crack was detected on the starter ring gear at the
edge of a lightening hole. Cracks were detected on starter ring gears
of powered sailplanes of another manufacturer with a very similar
design, which led to a loosening of parts. It must be expected that
similar damage can occur on the above-mentioned aircraft. Schempp-Hirth
has issued Technical Note 825-49/868-20 to address this condition.
The European Aviation Safety Agency (EASA) issued Emergency
Airworthiness Directive 2010-0039-E, dated March 11, 2010. This
airworthiness directive requires an inspection of the starter ring gear
and the accomplishment of the relevant corrective actions as necessary.
The actions specified by the EASA AD are intended to prevent substantial damage to the aircraft.
Recommendations
We recommend all owners and operators comply with actions outlined in EASA AD 2010-0039-E and Technical Note 825-49/868-20.