Capt.Doug
December 1st 06, 02:35 AM
>"Mark Levin" wrote in message
> As was pointed out to me the Beechcraft Baron does not use contra-rotating
> propellers. A bit of research showed me that most U.S. built light twins
do
> not use them either.
> My question is why?
Cost has been pointed out, however the Piper Navajo Chieftain has
counter-rotating props (as opposed to contra-rotating) and no one mentions
that they didn't buy a Chieftain because of the extra cost. The internal
engine parts that differ from each side are well stocked by parts suppliers
and therefore differ little in price from each other.
Not mentioned by other posters is that stability in twins can be affected by
which way the props rotate. The P-38 Lightning and Ted Smith Aerostar are
examples of this. Counter-rotate the props one way and get better
performance at the cost of stability. Turn the props in the opposite
direction and get better stability at the cost of performance.
D.
> As was pointed out to me the Beechcraft Baron does not use contra-rotating
> propellers. A bit of research showed me that most U.S. built light twins
do
> not use them either.
> My question is why?
Cost has been pointed out, however the Piper Navajo Chieftain has
counter-rotating props (as opposed to contra-rotating) and no one mentions
that they didn't buy a Chieftain because of the extra cost. The internal
engine parts that differ from each side are well stocked by parts suppliers
and therefore differ little in price from each other.
Not mentioned by other posters is that stability in twins can be affected by
which way the props rotate. The P-38 Lightning and Ted Smith Aerostar are
examples of this. Counter-rotate the props one way and get better
performance at the cost of stability. Turn the props in the opposite
direction and get better stability at the cost of performance.
D.