Accident Overview
On 24 April 2021 at approximately 19:15 local time, an unregistered homebuilt motorized deltaplane (microlight) crashed near Riidaja Airfield (EERD), Estonia. The aircraft was destroyed and the pilot sustained serious bodily injuries.
Aircraft and Pilot Information
The aircraft was a homebuilt motorized deltaplane consisting of an Apogee 14 'Flash' wing, an Apollo DeltaJet2 trike, and a Suzuki G16 engine. It was not registered and did not possess a valid airworthiness certificate.
The pilot, a 55-year-old male, did not hold a UL class A pilot license. He had 35 hours of total flight experience on a 'Polaris' motorized deltaplane, but only 0.5 hours on the accident aircraft as of the accident date.
Sequence of Events
From approximately 16:00 local time, the pilot conducted practice flights on the upwind portion of the runway, performing short, repeated low passes. At around 19:14, during a flight, the aircraft unexpectedly gained altitude, climbing to approximately 20 meters above ground.
To avoid landing in a field, the pilot decided to continue the flight, execute a left turn over a forest at the end of the runway, and land on the downwind portion of the runway. During the maneuver, the aircraft encountered a downdraft (tailwind) and turbulence generated by local obstacles (forest). It rapidly lost airspeed and crashed around 19:15 on a field near the runway end.
Investigation Findings
The Estonian Safety Investigation Bureau (OJK) examined the aircraft's structural damage, which was consistent with ground impact. No pre-existing technical failures or inflight structural breakups were identified.
The investigation determined that all damage resulted from the collision with the ground, ruling out mechanical or structural failures as contributing factors.
Probable Cause
The pilot's decision to perform a maneuver in an unfavorable location, altitude, and airspeed.
Safety Recommendations
The OJK recommended that the Transport Administration enhance awareness among ultralight aircraft operators regarding the importance of obtaining a UL class A pilot license, registering the aircraft, and ensuring its airworthiness.