Ray 'ere,
Anyone ever thought about installing canards on the F-16....They work a dream on a Stryker according to a guy around here...!!

Meanwhile back on the heli ranch....
I have a problem with my 400:
She went ploughing the other weekend and ended up striking the ground on her sidebut....visibly didn't damage much so, to play safe, I stripped the transmission down and replaced the main driveshaft, flybar and feathering shaft. Also replaced the coupling bolts between the main gear and the shaft and the shaft and head assembly. Installed new CNC blade grips too.
I went carefully through the setup of the flybar and its blades and it is a good as I can get it.....but......

I put a little power to her without main blades and I have a one time "chirp" sound accompanied by a tail twitch counter clockwise just as she picks up speed....just one click on the trim between start and stop. It's not periodic...just at slow spoolup.
My backlash is good and belt tension is OK
I'm feeling near a millimetre end play if I lift up the motor outer cage...is that a problem...?
Any help you can offer would be greatly appreciated.
Meanwhile, I'm gonna tear her down again and add one component between spoolups at a time to see if that will zero me in on the problem.
Ray