DG 100 elevator control fails on aerotow — maintenance defect
On June 1, 2009, during an aerotow launch from Pasewalk, a DG 100 exhibited untypical elevator movements on the takeoff roll. After the towplane lifted off, the pilot released the cable; the glider rolled at high speed off the east boundary into a grain field, destroying both wings. The elevator bellcrank's mounting bolt had pulled out of its laminate — installed without the required washer specified by 1978 AD 78-164. AD compliance was logged in the records, but the washer was missing.
- Aerotow takeoff roll: During an aerotow launch from Pasewalk, the DG 100 began its takeoff roll behind an ultralight tug.
- Elevator linkage failure: A previously unrecognized defect in the elevator control system manifested when the elevator bellcrank mounting bolt, inadequately secured in the laminate, detached during the takeoff roll.
- Improper bellcrank mounting: The elevator bellcrank mounting bolt had been laminated without the required washer, contrary to the technical directive and airworthiness directive, weakening its attachment.
- Unstable pitch behavior: Witnesses observed the glider briefly lifting off multiple times with untypical elevator movements, indicating degraded elevator control as the towplane became airborne.
- Tow release on roll: After the towplane had lifted off, the glider pilot released the tow rope to abort the aerotow due to the abnormal behavior.
- Overrun into field: Following the tow release, the glider continued at high speed, rolling beyond the eastern airfield boundary into an adjacent grain field about 10 meters outside the airfield.
- Crash - no injury: The glider came to rest in the grain field with both wings destroyed, while the pilot exited the aircraft uninjured.