What happened
On the day of the accident, a Piper Aerostar 601, registration N3645D, was on approach to the airport while a Bell 412 helicopter, registration N78S, was performing a departure. During the approach, the crew of N3645D noted that the nose gear indicator light failed to illuminate, leaving them unable to confirm if the nose gear was properly locked in the down position.
As the helicopter crossed under the flight path of the fixed-wing aircraft, the crew of N78S observed the Piper Aerostar 601 and reported that the nose gear appeared to be extended. This observation was corroborated by air traffic control personnel, who also noted the gear appeared to be down. After being cleared for a downwind turn, the captain of N3645D accepted an offer from the helicopter crew to fly in close proximity to inspect the landing gear.
During this maneuver, the helicopter moved from the left rear of the aircraft to the right side to conduct a visual inspection. While the helicopter crew initially reported that the gear appeared functional, a collision occurred between the two aircraft shortly thereafter. Both aircraft crashed to the ground. The accident resulted in five fatalities, including all three occupants of the Piper Aerostar 601 and both pilots of the Bell 412. Additionally, four individuals on the ground sustained injuries, one of which was serious.
Findings
Investigations revealed that no mechanical failures were responsible for the crash. A primary contributing factor was that neither pilot had received training for flying in close proximity to another aircraft. Furthermore, the captain of the Piper Aerostar 601 demonstrated a lack of proficiency regarding aircraft systems. The operator was also noted to have lacked sufficient FAA oversight. Additionally, the emergency procedures within the Aerostar flight manual did not provide adequate instructions for managing an emergency gear extension.