Amateur/Home Built/Experimental
Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 30; Flight Crew Total 470; Flight Crew Type 150
Situational Awareness; Troubleshooting
Aircraft Equipment Problem Critical
Aircraft Aircraft Damaged; General Maintenance Action
Aircraft
The nose gear of a canard pusher experimental aircraft collapsed on touchdown and landing rollout. Touchdown was not harder than usual. I shut down the engine and advised ATC by radio that this had occurred; and the following aircraft was sent around. I advised ATC that I would have to get out of the aircraft and push it clear of the runway. They acknowledged and asked that I report clear; I did so. Tower asked me to monitor Ground Control frequency as I pushed the aircraft further about 200 FT to the ramp. I did as requested and Ground Control called to confirm that I was 'in the parking area'. I confirmed that I was clear of the movement area; pushed the aircraft to my hangar and secured it. The Rutan-style canard pusher aircraft (VariEze and Long EZ) feature a hand-cranked worm gear mechanism as the standard method of raising and lowering the gear. On examination of the mechanism it was evident that the worm gear had stripped its teeth and this was the cause of the collapse. This has been known to occur with other Rutan-style canard pusher aircraft using the same mechanism; with no obvious warning signs. Suggest preventative replacement of the gear with one made from a stronger/tougher alloy.
A VEZE nose gear collapsed on touchdown because the worm gear extension teeth were stripped.