The aircraft was undergoing its first flight following an accident in which the landing gear had been torn off. As the gear was selected up after take-off, a loud bang was heard and shortly afterwards the low hydraulic pressure warning light illuminated. The crew observed that the nosegear was in a partially extended position, and all attempts to raise or lower it to a locked position were unsuccessful. Touchdown was made on the mainwheels and the aircraft slid to a halt on its nose when the nosegear collapsed. The nosegear doors were found to be incorrectly rigged, and the hydraulic system relief valve had been set to a higher than recommended pressure. An hydraulic line had burst, and the consequent loss of pressure prevented the nosegear from extending or retracting. The emergency gear lowering system had failed to operate when a retaining clamp did not prevent the actuating cable assembly from slipping.
