On the ground, in 747, we occasionally shut down the engines with these.
To see... if they work.
Often an excellent idea - With the mob I used to work for, that was tried on one of the 747's on engine #1. After twenty seconds or so at idle power (most people don't know it takes that long at idle after you pull the handle to get shutdown) the #2 engine quietly shut-down, with #1 still running away nicely.
Oh joy .....
