The aircraft departed Sydney on 8 August 1987, with the pilot and eight French tourists, for a twelve day Air Safari. The trip was uneventful until about 35 km west of Mt Isa, when the left engine failed during the descent. The pilot did not attempt to lower the landing gear and flap until the aircraft was on final approach. However, the landing gear did not extend. A go-around was carried out and on the subsequent circuit the pilot attempted to release the hydraulic hand pump so that he could manually pump the gear down. He was unable to release the handle. This fact, combined with an indication of rising temperatures on the operating engine necessitated a reduction in power on that engine, with a resultant loss of aircraft performance. The pilot then decided to carry out a "wheels-up landing" on the grassed area adjacent to the main runway. During the approach and landing the cowl flaps on the operating engine remained closed. An inspection of the aircraft revealed that the engine failed due to the separation of the induction system when the number 3 cylinder hold down bolts broke. These bolts failed as a result of fatigue probably as a result of the studs either not being torqued correctly at installation or becoming loose in service. The landing gear failed to extend by the normal method due to too low a hydraulic pressure possibly caused by low fluid level in the reservoir. It was found that the hydraulic hand pump handle required a two-handed effort to release it. This was due to it being clogged with dirt and old grease.
