Re: Light-Sport Aircraft Yahoo group Answer to Rich's Question

I guess I'm just not getting the point and what it has to do with the discussion about what turns the airplane.  You mentioned crab in the previous post and since I had always heard the word crab used in relation to a crosswind I had no idea what you were talking about and I still don't.  I think we have a definition problem that is not allowing us to communicate.  I don't know what crab means in the context you are using it.  I also don't understand what you mean by looping vector. 

 

But definitely, rolling the lift vector to the left or right does turn the plane IF we have lift associated with the vector.  We go where our lift vector takes us.  In the movies, fighter pilots are always looking through their gunsight because that looks cool on the big screen.  In reality, they spend their life looking straight out the top of the canopy, because that's where the lift vector is and that's where they are going.  (For the nitpickers, yes, of course a portion of the flight is spent looking straight back and some looking straight forward.)

 

When I am rolling towards knife edge, my nose doesn't loop toward the center (i.e., begin a turn) because I do what you said, I 'properly' remove the elevator input and place it to neutral.  But then you say banking would crab us in the direction of bank and I'm not following that at all.  The bottom line for me is that I move the controls in the direction it takes to keep the nose exactly where I want it to roll around a point without turning.  Control inputs during a roll include aileron in one direction and rudder and elevator in both directions at different points in the roll.  Whatever it takes to keep the nose sitting in it's proper spot.  I'm just not getting the point you're trying to make and don't get the crab part.

 

Jim Bair

 

From: Bill

Sent: Friday, March 09, 2012 9:32 PM

To: Sport_Aircraft@yahoogroups.com

Subject: Re: Light-Sport Aircraft Yahoo group Answer to Rich's Question

 

 

I guess the distinction that aileron rolling the lift vector to the left or right does
not turn a plane, it only would crab the plane. The rotation about a point to the left
or right comes from the elevator up that loops the plane when the looping vector isn't
offset by the weight of the nose in a turn.
Bill

---------- Original Message -----------
From: "Jim Bair" <mailto:jimbair%40live.com>
To: <mailto:Sport_Aircraft%40yahoogroups.com>
Sent: Fri, 9 Mar 2012 20:46:50 -0600
Subject: Re: Light-Sport Aircraft Yahoo group Answer to Rich's Question

> Hi Jim,
>
> Are you missing some of what is going on?
>
> Hi Bill,
>
> Probably. That would be normal. haha.
>
> In level flight, so that we have positive stability, we have our CG ahead of
> our CP(center of pressure) - ie: we are nose heavy. To counter that, we apply
> up elevator for our straight and level flight. When we go towards knife edge,
> that non-neutral elevator will cause the nose to rise (loop), since the
> elevator isn't *fully* being used up keeping our nose up from gravity's pull.
> This, in effect, will cause us to 'climb/loop' towards the center of the
> circle when we bank. If we 'properly' remove the elevator and place it in true
> neutral (down from straight and level flight), then banking would only crab us
> in the direction of bank. It is only the elevator's uppness that causes us to
> turn when we are on our side, or any fraction thereof.
>
> Actually, I thought [UTF-8?]that’s what I said. [UTF-8?]It’s our elevators
uppness that
> makes us turn. OK, I give. What am I missing?
>
> Jim
>
> Bill
>
> .
------- End of Original Message -------

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