You need to be careful when doing this - if only when it comes to briefing your colleague.
When I was doing my multi-engined training in the RAF we used the Jetstream to train on and sometimes took 2 trainees and 1 instructor up for a 3 hour flight as this saved airframe/engine cycles. On the occasion in question, I had flown the first 1 1/2 hours under training and my mate was taxying in after flying his 90 minutes.
Just as we pulled into the parking apron, making the final right turn onto stand, the instructor shut down the righthand engine (the one inside the turn) without warning us. My mate in the lefthand seat though "s*it" and shut down the left engine thinking we had a problem. This left the instructor to explain to the engineers why we were shutdown in the middle of the pan waiting for a tug.
Now, 30 seconds of briefing...................
I shall not embarrass the gents in question by telling you where they are working now.
As for the merits of shutting down - on a lightweight VC10 it is a good move as it allows you to lay off the brakes, the remaining engines will not need to come above idle and there is little or no nosewheel scrub (the fuselage is a great place to fit the engines). Either shut down one or one from each side (usually inners as the outers have the reversers) and you still have all electrics and full hydraulics.
Anything that makes a VC10 even a tiny bit quieter has to be a good move.
[ 12 November 2001: Message edited by: moggie ]