What happened
On 12 June 2005, a Cameron Z-250 balloon, registration G-CDIN, was conducting a passenger flight in Kent. After assessing weather conditions at Leeds Castle and Headcorn, the pilot commenced the flight from Headcorn. As the balloon ascended, the pilot noted that wind speeds at 2,500 feet were significantly stronger than anticipated, reaching between 15 and 20 knots.
While attempting to navigate toward Challock Airfield, the balloon crossed a ridge of elevated terrain. At a low altitude, the aircraft encountered a downdraft and sinking air on the lee side of the hill. This caused the burner frame to strike a concrete and brick bunker. The impact was followed by a secondary strike against an embankment, after which the basket slid into an elderberry tree. The balloon eventually came to rest against a tree in a hedgerow. The incident resulted in 3 serious and 8 minor injuries to passengers, and the pilot sustained a serious injury involving a dislocated shoulder.
The investigation
Investigators examined the aircraft's technical condition and the meteorological data available to the pilot. The Cameron Z-250 was found to be in good working order, with no evidence of incorrect rigging or mechanical failure. The burners and fuel supply were functional, with sufficient gas remaining for further flight.
Data recovered from the pilot's GPS confirmed the flight path and the timing of the impact. The investigation also reviewed the accuracy of the weather forecasts used for flight planning. While the pilot had consulted both the Met Office Ballooning forecast and a commercial service, the actual wind speeds at 2,000 feet were higher than those predicted by these sources.