CIRCUMSTANCES: At 1025 hours Eastern Summer Time on 14 February 1991 Gulfstream Aerospace AC 681 aircraft VH-NYG was entering the downwind leg of the circuit for a landing on runway 30 at Tamworth New South Wales when the pilot requested a clearance to land on a cross runway runway 18. When the aircraft was about 300 ft above the threshold of runway 18 the pilot advised that he was going to conduct a left orbit. During the orbit a high rate of descent developed. The aircraft crashed in a wings-level attitude 350 m short of the threshold of runway 18. The aircraft was destroyed by impact forces and the pilot its sole occupant was killed. Findings 1. The pilot was medically fit correctly licensed and qualified to undertake the flight. 2. Meteorological conditions and sun angle at the time of the accident were not significant. 3. The fuel planning figure given by the endorsing pilot was incorrect. 4. Neither the company nor the pilot established the correct fuel usage rate for the aircraft. 5. The engines' fuel flow indications were incorrect. 6. The fuel quantity gauge indications may have been erroneous. 7. The 'fuel level low' warning system was probably not functional. 8. The aircraft was not loaded with sufficient fuel to complete the flight. 9. Both engines failed due to fuel exhaustion. 10. The pilot probably did not realise that the fuel was exhausted. 11. The initial impact with the ground was not survivable. RECCOMENDATIONS: Early in the investigation the Civil Aviation Authority was advised of certain apparent operational irregularities. Consequently no new recommendations arising from the investigation were considered necessary.