"Mxsmanic" wrote

I note that the Baron (and presumably other twins) has a prop sync switch
that
somehow synchronizes the prop speeds on both engines. From recordings
I've
heard of the interior noise of the aircraft, it does sound as though props
that are just slightly out of sync can produce a very irritating
intermittent
noise as they move in and out of phase.

Slightly out isn't as bad as way out IMO. One of our guys likes to fly with
that wow-wow-wow-wow going on for hours and it drives me nuts when I'm the
passenger. It's all I can do to prevent myself from reaching over and
adjusting the props myself.

Also, how does the prop sync work? Does it actually move pitch or
throttle
levers or something?

In our aircraft there are pulse generators that monitor engine rpm and feed
a computer. The computer directly controls the right engine prop governor.
The system only works if the engines are already within 50 rpm of each
other. Even then, the system can take up to a minute to sync the props -
it's much easier and quicker to do it manually. Ours has never worked all
that well and we really don't use it, or need it for that matter.

BDS