Substantially damaged 16-2-1991 when made a wheels-up landing at Hatfield, Hertfordshire. No injuries sustained to the two persons on board (instructor and pilot under training). According to the following extract from the official AAIB report into the accident: “The aircraft had positioned from Biggin Hill to carry out crew training at Hatfield and had flown a missed approach to Runway 24 and a touch-and-go on Runway 06 during which engine failures had been simulated. Following the touch-and-go, the instructor reduced power on the left engine, and told the pilot to assume that he only had emergency brakes available to bring the aircraft to a stop on the next landing. An approach was flown to Runway 06 and the aircraft landed with its undercarriage retracted. The accident happened in daylight (13:39 Local Time) and in VMC. During the final circuit, the instructor had been explaining the procedure for a landing without the normal brakes being available, at the time the undercarriage would normally have been selected down, and, as a result of this, the undercarriage was not extended. After the accident, the crew reported that the undercarriage warning horn had sounded each time the instructor had reduced power, and that the instructor had cancelled it each time. During the last approach, the horn sounded again and the instructor automatically cancelled it.” Damage to airframe: Per the AAIB report “damage to fuselage underside, rear pressure bulkhead, and flaps”