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Guess I took ten minutes too long writing the above and should've waited for SoD to get done.
My explanation, if they were having turbulence problems due to the center section, would then just be an unintended or at the least collateral benefit.
Ah well, I should be in bed anyway.
Gary
A counter-rotating prop, i.e. clockwise rotation as viewed from behind, is just the opposite as far as torque and p-factor. Thus in a homebuilt with a Rotax engine with a PSRU, you need LEFT rudder during a takeoff because the prop rotates opposite to the norm.
As a Brit i`m not used to american terminology. To me a counter rotating prop is two props one behind the other eg:An 70,Spitfire F.Mk 21 or the Fairey Gannet.
VERY COOL!>Fly twins?
Quite regrettably I don't have multi engine ratings but I have flown in one, a DC-3 from the right seat. You can see my left shoulder. It was fun, of course.
A counter-rotating prop, i.e. clockwise rotation as viewed from behind, is just the opposite as far as torque and p-factor. Thus in a homebuilt with a Rotax engine with a PSRU, you need LEFT rudder during a takeoff because the prop rotates opposite to the norm.
What isGary McCL referring to. Two engines turning in different directions.
simply stated - if a rotor or prop turns (top to bottom) one way, the fuselage holding the sucker wants to rotate the other way ... so aileron and rudder (or tail rotor thrust) needed to 'counteract' that nasty 'ol prop.
Of couse in case of Helo, some tail rotors 'pull' into fuse and others 'thrust'. An imbedded tail rotor simplifies the aerodynamics of the tail rotor. 'lose a tail rotor and you can kiss your ass goodbye if you have any altitude at all. Very bad 'thing'. It has been a very long time but I believe the King Cobra at Bell had a huge (4 bladed -two engine) rotor system delivering 600,000(??) pounds of torque. (Don't hold me to the very big number - my memory is not reliable here)
Joe dead on on reducing power on TO for a lost fan on a 38... because as he explained it the asymmetrical thrust for live engine (and lift on live wing) turns everything to dead engine - a very bad thing. Of couse it has to be done slowly..
SoD correct about the actual design reasons for 38 prop rotation scheme due to effect on centerbody/wing area..
Counter rotating props is termed when you have props turning opposite directions from each other - it is not related to the direction of rotation of a single propeller. We term contra-rotating props two props rotating in opposite directions on the same axis.
In the US, at least for mil aircraft, props generally rotate clockwise. In our helos the rotors generally spin CCW.
That's what I thought, but GaryMcl seems to be saying that counter-rotating means counter-clockwise-rotating...
Counter rotating props is termed when you have props turning opposite directions from each other - it is not related to the direction of rotation of a single propeller. We term contra-rotating props two props rotating in opposite directions on the same axis.
In the US, at least for mil aircraft, props generally rotate clockwise. In our helos the rotors generally spin CCW.