Incident Overview
During the approach phase, the pilot selected to extend the landing gear but did not receive a green light confirming that all three landing gear were down and locked. The pilot then checked the electrical fuses and performed several cycles of gear extension without any change in the landing gear position indication. Subsequently, the pilot pumped the emergency gear extension hand pump.
Low Fly-By and Visual Verification
The pilot advised air traffic control and was instructed to perform several low fly-bys. Tower and fire rescue personnel visually verified that all three landing gear were down.
Landing Gear Collapse
As the airplane's main landing gear touched the runway in a soft field-landing configuration, the right main landing gear collapsed.
Statement from the Pilot
The pilot stated that he pumped the emergency gear extension pump handle until he felt resistance. He could not recall the exact number of strokes, estimating between two and three strokes.
Post-Incident Operational Checks
The main landing gears were operationally checked once using the airplane's own battery power and twice using the emergency landing gear extension hydraulic hand pump for manual extension. The main landing gears extended and locked into position within 12 to 15 pumps of the emergency landing gear extension hydraulic hand pump. No defects were observed in the operation of the extension and locking of the main landing gears by hand pump.
Examination of Landing Gear Actuators and Locking Systems
An examination of the main landing left and right gear actuators and locking systems revealed no anomalies.
Flight Instructor's Account
Avion's chief flight instructor stated that close to a month before the accident, on the same airplane, he had to perform an emergency extension of the landing gear using the hand pump. He noted that it took anywhere from 10 to 20 pumps to lower the gear and into the lock position.
Checkout Procedures
According to the chief pilot who checked out the pilot, only verbal instructions on how to extend the landing gear by hand pump were given during the check ride in the airplane.