A private owner of a B206 upgraded to an AS350 - it was a Sneaky Rebuild from Canada, where the dataplate from a wreck, and one or two serviceable parts from it are surrounded by a brand new aircraft, thus avoiding the payment of the New Build Tax. This bird was a left-hand-drive, with a bench seat across the front and a nice set of Squirrel Cheeks for extra storage in the cargo compartment.
I went out with an experienced qfi to get an official endorsement on it - being LHD, the throttles etc were on the floor at the left door, inaccessible to the qfi on the RH bench seat, so for the GF sequences, I sat on the left side, and for the emergency bits we swapped seats.
All went swimmingly until it was time for some power terminated autos. We swapped sides, and after a perfect circuit for positioning, qfi pulled the throttle, I lowered the lever, and set up for the auto. On finals it was, of course, looking excellent. Here comes the flare, nicely judged, now a little pitch pull...... oh poo, the collective won't move!
"It's stuck! Collective stuck!" I called, and qfi also tries to pull, looks down and sees the collective lock had applied itself. He tries to unlock it, but he needs to push it down to do so, and I am pulling up like crazy - I win.
All this in 2 poofteenths of a second, I had already nosed over to retain some speed, and we hit the ground in a level attitude and with maybe 10kt. We bounced over a raised taxiway (really lucky as catching the toes would have rolled us over forwards) and landed next to a ditch on the ground on the other side. We slid to a stop in a cloud of dust and a hearty "hi-ho Silver!" whereupon I unstrapped, walked around to the left door, opened it, unlatched the collective lock, and broke it off so it would never offend again.
After an inspection to let us know the bird was perfectly fine, I hopped on the phone to the local Eurocopter representative to let him know that his collective lock design was defective and potentially deadly. He enquired which machine it was, and his reply was "Zat ees a Caneedian 'elicopter, eet ees not our concern." Which only reinforced my opinion of ze French support in Oz.