The maritime patrol aircraft was demonstrating low-level single engine flight at the Farnborough Air Show. The aircraft sideslipped at low altitude, a wing tip hit the roof of a hangar and the pilot was unable to recover. The aircraft crashed into airfield buildings. Cause: “As a result of the undercarriage having been left extended, it is possible that the air speed at the time of unfeathering the port prop was less than normal, and less than intended by the pilot. This in itself would not have resulted in an accident. Possibly because of [a] control jam, the rudder deflection necessary at this speed to balance the asymmetric thrust of the starboard engine and the drag of the unfeathered port propeller, was not applied. This was the most important cause, and allowed yaw, sideslip and roll to develop to the extent that the pilot had inadequate control of the port turn which he had initiated. The aircraft’s height and speed were insufficient to permit recovery by a reduction of power on the starboard engine. Bank therefore increased beyond the point at which level flight could be sustained, and the aircraft stalled in the turn and crashed.