What happened
On 7 May 1999, a Pitts S-1S, registration G-IIIX, was conducting a private flight from Breighton Airfield to Welshpool Airfield. During the flight, the pilot encountered deteriorating weather conditions, characterized by heavy rain and a cloud base that had dropped to approximately 500 feet. Due to these conditions, the pilot opted to divert to Derby Airfield.
Upon approaching Derby, the pilot was assisted by a radio operator who provided advisory headings to help the pilot locate the airfield visually. The aircraft was positioned for landing on Runway 23, a grass strip with a displaced threshold and a Landing Distance Available of 341 metres. The weather at the airfield was marked by heavy rain and a wind of 200°/7 kt. After an initial unsuccessful approach and a subsequent left-hand circuit, the pilot attempted a second landing.
Following touchdown, the pilot found that the braking action was insufficient. Fearing an overrun and having decided against a go-around due to the poor visibility, the pilot switched off the magnetos. The aircraft subsequently exited the runway into undergrowth, where the tail lifted and the Pitts S-1S overturned onto its back. There were no injuries to the pilot, though the airframe sustained damage, including a crack in the top right main spar.
The investigation
Investigators examined the circumstances surrounding the landing and the aircraft's performance on the grass surface. Observations from individuals at the airfield suggested that the aircraft had landed significantly beyond the runway threshold. The investigation also considered the pilot's decision-making regarding the approach and the use of the available runway area.