in answer to sasless the student pilot flys in the right seat and the removable duals are on the left hand side, the student therefor has the fixed controls.
a student pilot is not a rated helicopter pilot but when under instruction of an FI can operate the machine solo after a suitable briefing of what he is actually authorised to do.
there is much more to it than that , especially now here in the UK after JAR changes - i now have to fill in almost the same sortie details on 8 different forms for each flight!
rotorbike is quite right about the old design of collective locking , it was a little sprung clip that went around the lever and each end went into a hole in the lever through the sleeve - also the clip was free to detach so could get lost if the duals had been removed!
whirly the duals fit any machine so it wouldnt matter that much if they went in the 'wrong' a/c but leaving them under the seat is just begging for the pilot to put them back in to, Quote ' let his mate have a little go'!