What happened
During the landing phase, the aircraft dropped approximately 10 feet onto the runway. The impact was forceful enough to cause concern for both the pilot and the operator. Following the touchdown, the gear warning horn activated. The pilot inspected the landing gear and bent the squat switches in an attempt to silence the horn before performing a test flight.
Although three green gear down lights were visible prior to landing, the left landing gear collapsed during the aircraft's rollout. Before coming to a complete stop, the aircraft struck a sign and three runway lights. There were no injuries reported.
The investigation
An inspection of the landing gear was conducted by the FAA and a technical representative from Raytheon Aircraft Company. The technical representative determined that the downlock plates were bent as a result of the hard landing.
A review of the aircraft logbooks revealed that the aircraft had not received a primary 150-hour inspection since August 1993, meaning the aircraft was in an unairworthy condition. Due to the significant damage sustained by the landing gear components, investigators were unable to identify any preexisting anomalies within those parts.