Light twins not using contra-rotating propellers

The cost of manufacturing two versions of the engine and
recertification of the design is not worth the small
advantage. Most light twins were designed and certified
over 40 years ago.


"Mark Levin" wrote in message
...
| Hello,
|
| 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?
|
| It seems silly to me not to take advantage of having
various propeller
| effects cancel each other out unless there were overriding
engineering or
| cost issues.
|
| For single engine operations it seems that you would want
to match rotation
| to which side the engine is on so as to let propeller
caused turning
| tendencies to help offset the asymmetrical thrust. Though
I can imagine
| that asymmetrical thrust is so much greater than propeller
caused turning
| tendencies that this isn't really an issue.
|
| Are the added engineering/manufacturing/maintenance issues
for
| contra-rotating props that great?
|
| inquiring minds
| ml