Aircraft: Fusioncopter JK-2 Nano
Serial no: FCG014
Engine: Hirth F23
Serial no:MO-01000570
TIS: 25 hours
History: On pre-flight run-up checks, one ignition was found to be inoperative.
Analysis: One ignition kill wire was permanently grounded.
Traced to the 3PDT ignition master switch- one pole permanently made irrespective of switch position.
Switch was disassembled and one pole rocker was found welded in the made position.
The other ignition kill pole rocker also showed signs of arcing.
The switch is rated at 2A/260VAC- but the ignition circuit generates voltages well in excess of that.
The failure mode is most likely arcing/welding at the moment just prior to the switch closure to kill the ignition.
Corrective action:
The switch was replaced with the same type as an interim fix until a higher rated compatible switch is found.
Recommend that Fusioncopter upgrade the switch rating.
After Stuart reported the problem we decided to use a different switch. Currently, a switch corresponding to engine requirements is installed as standard. However, on my gyroplane, I stayed with the old one to see if the problem would also occur in mine. It's working fine so far.