What happened
On 23 April 2021, a Silent 2 Electro motor glider, registration G-CIRK, was performing a self-launched takeoff at Wormingford Airfield in Essex. During the initial ground roll, the aircraft's left wing touched the runway after the wing runner released the right wing. Shortly after, the propeller struck the runway surface, leaving several marks on the pavement.
Following the strike, the aircraft continued to accelerate and lifted off. However, the flight path transitioned from a shallow climb to an increasingly steep ascent. The aircraft reached a maximum altitude of approximately 100 ft before the airspeed dropped to 30 KTAS. At this point, the glider entered a stall and began a rapid left roll, entering an incipient spin. The aircraft struck the ground nose-first in a field near the runway. The pilot sustained one serious injury, and the aircraft was destroyed.
The investigation
Investigators examined GPS data from multiple flight loggers and ground-based FLARM recordings, alongside witness accounts and video footage of a previous flight. The data confirmed that the propeller strike occurred roughly 12 seconds into the takeoff roll but did not significantly impede the aircraft's acceleration.
Technical analysis of the Silent 2 Electro revealed that the aircraft lacked an energy-absorbing structure in front of the pilot's seat, which contributed to the severity of the pilot's injuries. The investigation also reviewed the manufacturer's Flight and Maintenance Manual, noting that it lacked specific instructions regarding target liftoff or recommended climb speeds.
Findings
- The primary cause of the accident was an excessive aft stick input during the climb, which was not corrected by the pilot.
- The steep climb resulted in a stall that was either not recognized or reacted to too late.
- Factors such as pilot workload, stress, or distraction likely contributed to the improper control input.
- The aircraft's handling characteristics, specifically low stick forces and minimal sensory feedback, made the situation harder to manage.
- Poor stall warning indications and the lack of a separate pitch trim lever further complicated the pilot's ability to maintain control.
Safety action
Following the investigation, the British Gliding Association (BGA) issued a safety briefing to owners of the Silent 2 Electro in the UK and the European Gliding Union. This briefing provides guidance on managing the aircraft's specific stick force characteristics, stall recognition, and takeoff handling techniques.