What happened
On 11 January 1998, a Fournier RF3, registration G-BNHT, was performing a private flight from Saltby, Lincolnshire, to LittleGransden, Cambridgeshire. During the transit, the pilot encountered worsening weather conditions, characterized by a dropping cloud base that eventually reached an overcast level of 1,500 feet. Visibility was estimated at 15 km with surface winds of 220/10 kt.
To avoid the deteriorating weather, the pilot elected to divert to the nearest available airfield, Sibson Airport near Peterborough. Because the aircraft lacked radio equipment, the pilot focused on flying a tight circuit pattern to signal intentions to air traffic control and to maintain a high level of vigilance for parachutists operating at the airfield. During this approach, the pilot failed to extend the landing gear, resulting in a wheels-up landing on Runway 25. The aircraft sustained minor damage to the propeller tips and came to a stop on the runway. The pilot escaped the incident without injury.
The investigation
The investigation examined the circumstances of the diversion and the mechanical state of the aircraft following the event. While the aircraft was repaired following the incident, investigators discovered a discrepancy in the landing gear warning system. During ground testing after repairs, the warning switch provided the correct visual and aural alerts. However, during a subsequent ferry flight, these warning indications failed to function when the aircraft was in the approach configuration.