Accidental Gear Retraction
 

Hello! Recently we had an incident when gear was accidentally retracted (C-172 RG) during preflight check ont he ramp. It was said that gear lever was in down position and nose gear sudenly retracted when master switch was pressed on... Has anyone idea what could be wrong? Thank You! ;)

Have you considered searching for an "Aircraft Engineer" and asking him or her to have a look?

I'd never have thought to search for one on the Engineer's forum at Proon :p

I haven't worked on a 172RG for many years so I'm a bit hazy.
There's a squat switch on the nose gear that's supposed to prevent retraction on the ground (and it might even cut out the power pack operation, I don't remember).
Did the gear warning horn sound when the master switch was selected (assuming the throttle was retarded)?
What gear indication lights were showing after the incident?

In the past the very few times I have seen it happen its usaully because the previous pilot has done something silly and not told anyone.