it is constant speed props on the Arrow and Cardinal..
and there is still a harmonic vibration range

BT

"Morgans" wrote in message
...

"Dudley Henriques" wrote

The Lockheed Electra sure could have used a prop AD for this one!

So there was a RPM restriction on the Electra?

What do you recall? Didn't a constant speed prop pretty much bypass it?
--
Jim in NC