hi backender
try doing a search for r22 blades & you'll get plenty of hits
of particular interest might be this fairly recent one: here
http://www.pprune.org/forums/showthr...ght=r22+blades
i'm not aware of any definitive study on the topic , but surely someone here would have some good directions, particularly the anti-Rxx crowd who seem to be able to come up with all the technical data