What happened
On 14 February 2011, a Bolkow BO 208C Junior, registration G-ATRI, was performing a private flight from Kingsmuir Airfield in Fife. During the takeoff roll, the aircraft reached an airspeed of 50 kt, which was just below the required takeoff speed of 55 to 60 kt. At this stage, the pilot noticed the airspeed indicator reading 40 kt, even though there was no visible change in the aircraft's groundspeed.
In response to the unusual instrument reading, the pilot attempted to abort the takeoff by applying heavy braking. However, the aircraft overran the 620 m runway and entered a ploughed field. As the aircraft moved off the prepared surface, the nosewheel sank into the soft ground, causing the aircraft to nose over onto its back. The two occupants, the pilot and one passenger, were able to exit the aircraft without any injuries.
The investigation
Investigators examined the circumstances surrounding the sudden change in airspeed readings and the aircraft's behavior during the overrun. The pilot noted that a heavy rain shower had occurred shortly before the incident. The investigation established that a sudden change in wind direction and strength had occurred during the takeoff run. This shift caused the initial slight headwind to transition into a significant tailwind, which affected the aircraft's performance and the pilot's perception of the takeoff parameters.
Findings
- The aircraft sustained damage to the propeller, the nose leg, the left wing skin, and both the front and rear canopies.
- The primary factor in the accident was a sudden change in wind direction and strength, which resulted in a significant tailwind during the takeoff roll.