During the approach to land the tower controller advised the crew of the BAe146 that the aircraft appeared to be trailing smoke. The crew responded that there was no cockpit indication of fire, but asked the controller "to keep an eye on it". The rescue firefighting service was then alerted and placed on local standby.
During the landing roll a fire service officer advised that there was smoke in the area of the auxiliary power unit (APU) jet pipe but that no flame was evident. The aircraft was taxied in normally, after which the passengers were disembarked through the forward entry door. During the disembarkation, flames were observed from the APU jet pipe and were quickly extinquished.
The crew advised that the APU had "overtemped and hung" during the startup sequence. It was soon after this time that the Tower controller reported smoke behind the aircraft. The APU was shut down and the integrity of the APU fire warning system confirmed. There was no indication of smoke in the cockpit or cabin.
Initial examination revealed a significant internal failure of the APU turbine. The subsequent fire was contained within the core of the APU and there was no external damage to the engine or to the air conditioning bay. The APU was removed from service for detailed bulk strip examination.