the added (non factory) bungee cord or other collective locking devices developed for australian bush helicopters is the norm.
these devices are installed because the factory frictions are not strong enough to hold the collective down for extended periods.
we have to exit the machines regularly during the course of a normal working day to get or give directions from the ground crew and it is not practical to shut down during the more difficult stages of cattle mustering. we exit the helicopter about four times a day, rotors running.
when we used bells there was not such a big problem but robinsons collectives have a habit of rising if they are not held down. with the overcorrellation of the r22 throttle and the increase in rpm that follows a rising collective there have been a few instances of machines becoming airborne and flogging themselves to death.
people have forgotten to use these added devices and have suffered the conseqences but generally since their introduction the accident rate has dropped to nearly zero.
this is not a big deal.