Hi Lu,
unfortunately my theory on helicopter design is rather very limited. I try to argue based more on common sense......
Though I have a mechanical engineering education it just lets me understand the basics what you and guys like Nick Lappos are talking about when the going gets deep...
But I am glad I do not disintegrate in the air when the friction values on the Robinson head change for whatever reason (like those poor guys in their Apaches...).
I had the unfortune to fly one Robinson 44 with one completely lose coning hinge once. It just jumps with one per rev.........
I still could fly it back to the shop.
The unlucky son of a b... of a mechanic did not heed the advice in the maintance manual, that the hinges have to be ABSOLUTELY clean during assembly. Grease - even fat from your own fingers are too much for teflonbased friction bearings. That happens when people (mechanics, pilots, etc.) know it all better than the guys who built the machine and write the manuals!!
3top
PS: Lu, as you are the "one" who started the 18 degree offset discussion: Do you still have all the arguments and responses?
I got to late into PPRUNE to catch that forum. However I would like to read about it. If you can send me an e-mail with some info on that!
Thanks
