What happened
On 13 June 1998, a Scheibe SF25B, registration G-AXEO, was being operated for private circuit training at the Milfield Gliding Site in Northumberland. The flight included the pilot and one passenger. Prior to the accident, the pilot had observed two other departures and noted that the takeoff runs appeared unusually long, though the aircraft climbed adequately.
During the departure, the aircraft was operating from a grass strip into a 10-knot wind. As the aircraft accelerated, it experienced several bounces before becoming airborne at approximately 50 mph. Despite a gradual increase in airspeed, the aircraft failed to establish a climb, leading to concerns regarding obstacle clearance at the end of the runway. The pilot attempted to raise the nose, but the aircraft stalled at an altitude of roughly 10 to 15 feet. The resulting impact caused substantial damage to the aircraft, including a broken propeller and structural cracking in the wings.
The investigation
The investigation examined the environmental conditions, the aircraft's performance, and the pilot's actions. At the time of the accident, a weather front was approaching, bringing drizzle and wave cloud formation. The investigation also reviewed the pilot's interpretation of the airspeed indicator (ASI) and the aircraft's aerodynamic characteristics during the takeoff roll.
Findings
- The takeoff occurred on a damp grass surface, which contributed to a longer takeoff run.
- There was the possibility of a downdraft caused by the approaching weather front or terrain features near the end of the strip.
- The pilot misread the airspeed indicator, mistakenly interpreting a reading of 50 mph as 50 knots due to previous experience with instruments calibrated in knots.
- The aircraft lacked a prominent stall warning, such as aerodynamic buffet, to alert the pilot to the impending stall.