What happened
On the morning of October 15, 1967, a pilot operating an SF 24 B Motorspatz-I, registration D-KIDU, took off from Spreitenbach, Switzerland. The aircraft, which the pilot had recently acquired, climbed to approximately 300 meters before encountering moderate turbulence.
During the flight, near the village of Niederrohrdorf, the aircraft was observed flying at a very low altitude, approximately 80 meters above the ground. Witnesses noted that the propeller was intermittently spinning and stopping, indicating repeated attempts to restart the engine. While executing a turn of more than 180 degrees, the aircraft entered a steep descent and struck a garden, nearly hitting a bystander. The impact resulted in the destruction of approximately 95% of the aircraft.
The investigation
The investigation examined the pilot's flight experience, the airworthiness of the SF 24 B Motorspatz-I, and the environmental conditions. The pilot had recently transitioned to motor glider operations, with only one recorded training flight on this specific type.
Investigators reviewed the engine's reliability, noting that on a previous flight, the engine had required multiple attempts to start at low altitudes. The investigation also considered the weather, which included significant mechanical turbulence caused by the local terrain and wind conditions. Due to the pilot suffering from retrograde amnesia following the crash, the investigation relied heavily on eyewitness accounts and flight logs.
Findings
- The pilot employed an inappropriate flight tactic by attempting to restart the engine at an altitude too low to safely manage the aircraft.
- The pilot likely focused too much on the engine restart process, neglecting the necessary preparations for an emergency forced landing.
- The aircraft entered a loss of airspeed during a maneuver, leading to the stall and subsequent crash.
- While the exact cause of the speed loss could not be definitively determined due to the pilot's memory loss, the aircraft was in an airworthy condition prior to the accident.