Aircraft
Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration
CE-08-23
May 22, 2008
This is information only. Recommendations
aren’t mandatory.
Introduction
This Special Airworthiness Information Bulletin informs you of an
airworthiness concern for Alexander Schleicher powered and non-powered
sailplane Models ASW 22, ASW 22B, ASW 22BL,
ASH 25, and ASH 25E, all serial numbers. The European Aviation Safety
Agency (EASA) has issued Airworthiness Directive (AD) number 2008-0059,
dated March 26, 2008, for those sailplanes registered for operation in
Europe. That AD is based on Alexander Schleicher Technical Note No.
16/20/28, EASA-approved on March 18, 2008.
Background
A partially broken lever of a flap control system on a Model ASH 25
was discovered during a service inspection. Further investigations
performed on a few sailplanes of a similar design have revealed gaps
between the bearing flange and the lever plate, which indicates a bent
lever, and/or blackcolored borders around the rivet heads, which
evidences deterioration of the lever. Rupture of such a lever, located
in the fuselage behind the rear cross tube, would lead to a symmetrical
failure of the flap system and would result in a limited
controllability and higher minimum speeds.
The EASA AD requires an inspection and replacement of the flap control
lever with one of improved design, as instructed in the above
referenced Alexander Schleicher Technical Note.
Recommendations
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. However, we
recommend all owners and operators comply with actions outlined in
Alexander Schleicher Technical Note No. 16/20/28.