The aircraft had not flown since December 1985 and had been parked in the open. The Maintenance Release had expired, and a Permit to Fly was obtained to allow the aircraft to be ferried to Parafield for maintenance. When the gear was lowered for landing, only the nosegear indicated that it was down and locked. Recycling the system did not result in locked indications being obtained for the maingear, although to persons on the ground it appeared to be down. During the subsequent landing roll the right gear collapsed. The aircraft had been inspected prior to the flight and the engineers had noted that the gear bearings were dry and slightly corroded. They did not bring this to the attention of the pilot and he did not detect the condition during the preflight inspection. When the gear failed to fully extend prior to landing, because of lack of lubrication and corrosion, the pilot discussed the situation with an engineer on the aircraft and they decided that the fault was probably in the gear position indication system. As a result no attempt was made to lower the gear using the emergency system.
