What happened
On 11 August 1998, a LBL 180A Balloon, registered G-EVNT, was conducting a public transport flight near Colerne Airfield in Wiltshire. As the aircraft approached the landing site, the pilot observed via GPS that the wind speed at 50 feet was 14 knots, which was higher than the forecasted surface winds of 7 to 8 knots.
The flight path for the final approach took the balloon over a row of trees positioned perpendicular to the direction of flight. While passing over this obstacle, the balloon encountered a sudden downdraft. This downward air movement caused a rapid increase in the rate of descent that the pilot could not counteract. Consequently, the balloon made a heavy landing on the airfield. The impact caused the balloon to bounce before it eventually came to a rest. While there was no damage to the aircraft, one passenger sustained serious injuries, specifically two broken legs.
The investigation
The investigation examined the meteorological conditions and the flight path during the approach to Colerne Airfield. Investigators reviewed the pilot's observations regarding wind speed discrepancies between the forecast and the actual conditions recorded by the GPS at low altitude. The investigation also focused on the impact of the terrain and vegetation on the local airflow during the final stages of the flight.