What happened
On 26 June 1999, an Aeronca 7AC Champion, registration G-AJON, was performing a local private flight departing from Oaklands Farm Strip near Stonesfield, Oxfordshire. During the final stages of the flight, the pilot attempted an approach to Runway 12, a grass strip measuring 400 metres in length.
At the time of the incident, weather conditions were favorable, with the pilot estimating surface winds from 200 degrees at between 5 and 12 knots. As the aircraft approached the runway, it encountered power lines situated roughly 150 metres from the threshold. To maintain safety, the pilot had increased engine power to ensure sufficient vertical clearance over these cables. However, the aircraft encountered turbulence and a loss of lift caused by the lee of nearby farm buildings. Despite the application of full power, the aircraft struck a cable, causing the windscreen to shatter. The pilot sustained minor injuries, specifically a cut above the eye, which caused blood to obstruct his vision. The pilot was subsequently able to execute a go-around and complete a successful circuit and landing.
The investigation
The investigation was based on the aircraft accident report form provided by the pilot. The inquiry focused on the flight path relative to the obstacles on the approach and the aerodynamic effects of the surrounding structures. The investigation established that the presence of farm buildings created localized turbulence that contributed to the aircraft's descent toward the cables.