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--- Scott Owen  wrote:

> your understanding of helicopter aerodynamics is off a just little
> bit.

Well, maybe - I have a bunch of ratings (commercial, instrument, ground
instructor, etc.) but they're all for fixed-wing aircraft.

> ALL the U.S. helicopters I have flown had left main rotor rotation.

"Left" is a bit ambiguous (depends on what part of the helicopter
you're using for reference, or is there a standard for that in the
sling-wing world?)

> The primary issue of main rotor rotation direction is to have
> a tail rotor design that counteracts main rotor torque.  In short,
> the  purpose of the tail rotor is to counteract main rotor rotational
> torque.

Correct.

> Whoa... I don't buy the pilot sits on the left side to "balance out
> the forces of the tail  rotor"... this is just wrong.

I don't buy that either, but that wasn't what I said...

> Most modern helicopter designs have a main rotor shaft that is
> slightly tilted to counteract aircraft drift in a hover.

Which is what I said...

> This main rotor tilt does little to prevent the helo from hovering
> with one skid low.

Exactly.

> In all left rotating main rotor helos the left skid will be low in a
> hover hence the "pilot" position is on the right side because this
> position is  "higher" and that "pilot seat" has better visibility
> forward in a hover.

Well, that explanation makes sense too - I was just repeating what I'd
been told (and I only have a couple hours of rotary time, so I'll defer
to your expertise on that if you've got a different theory).

> The only helo that doesn't hover with one skid low is one that has
> counter-rotating main rotors and then there is NO tail rotor as it
> isn't needed.

Correct, the torque from both main rotors cancel each other other.

--
GregR


>
> Hmmm... well I know this is off topic and if Frank wants he can not
> let
> this through; but Greg, your understanding of helicopter aerodynamics
> is
> off a just little bit.
>
> Greg R. wrote:
>
> > The Eurocopter (French) models are designed to rotate in the
> opposite
> > direction of most of the ones from North America, and (without
> going
>
> Fine.  ALL the U.S. helicopters I have flown had left main rotor
> rotation.  The primary issue of main rotor rotation direction is to
> have
> a tail rotor design that counteracts main rotor torque.  In short,
> the
> purpose of the tail rotor is to counteract main rotor rotational
> torque.
>
> > into a lot of nitty-gritty detail) the pilot sits on the left side
> to
> > balance out the forces from the tail rotor (plus the fact that the
> main
>
> Well the devil is in the details isn't it.  Whoa... I don't buy the
> pilot sits on the left side to "balance out the forces of the tail
> rotor"... this is just wrong.  There are two pilots seats left and
> right
> and there location in the airframe only deals with the best position
> fore and aft for weight and balance around the CG of the airframe and
>
> has nothing to do with "balancing tail rotor forces".
>
> > rotor is tilted slightly to compensate for the sideways thrust of
> the
> > tail rotor) - otherwise the 'copter would hover with one skid low
> on
> > the side that the main rotor was tilted towards.
>
> Most modern helicopter designs have a main rotor shaft that is
> slightly
> tilted to counteract aircraft drift in a hover.  This main rotor tilt
>
> does little to prevent the helo from hovering with one skid low.  In
> all
> left rotating main rotor helos the left skid will be low in a hover
> hence the "pilot" position is on the right side because this position
> is
> "higher" and that "pilot seat" has better visibility forward in a
> hover.
>   If the french helo has right main rotor rotation then that helo
> hovers
> right skid low and the "pilot" position would then be on the left
> because this is the "higher" seat in a hover.  The only helo that
> doesn't hover with one skid low is one that has counter-rotating main
>
> rotors and then there is NO tail rotor as it isn't needed.
>
> --Scott
>
> >
>


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