I find that RVSM is fine, but a little nervy in turbulence!. .I don't understand why they introduced it at alternate levels though. It would have been a better idea, in my point of view, to introduce the levels in pairs, eg. f350 and f360 westbound, f370 and f380 eastbound and so on. This way transition between rvsm and non rvsm would be much smoother, as less level changes would be required, and the old semi-circular rules would still work, making life easier for airmen and controllers alike in knowing if they were at the correct level. It seems silly to me that f350, an old westbound level is now an eastbound level. Any comments...? <img src="confused.gif" border="0">