To: imabell
Nothing was said about a Bell 47 helicopter. Although you didn’t see it, the engine / transmission combination moves up and down to the limits allowed by the two Dynafocal mounts attached to the engine /transmission support cage. The movement is minimal but it is there. There is however something common on the 47 that happens on all of the other Bell 2-blade helicopters and that is the 2-per rev, which gives you a vertical beat.
Also on the 47, the pylon (Mast) and engine will deflect to the limits of the Dynafocal mounts and if the pilot takes it beyond those limits he will come up against the sprague cables on the bottom of the engine. If he goes any further, the mast will bend and cause a growling of the gears in the transmission.
------------------
The Cat