Posted Sunday, April 12, 2009 @ 01:01 AM
Beware of using carbon-fibre propellers on direct drive engines.
They're OK on geared motors (Rotax etc) but dangerous on direct drive because they can come apart very quickly (milliseconds) in flight due to the engine's pulses.
Carbon fibre sheathed woden props might be OK, but remember Rolls Royce went bust when they put carbon fibre fan blades on the RB 211 (fan rpm around 1,500 to 2,000 rpm). The blades went furry and broke up when encountering rain.
A wooden prop on a wooden airplane sounds to me like tried-and-trusted technology.