REFLECTOR: 65VT/ angle-of-attack system

[Brian Michalk]

> -----Original Message-----
> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org]On
> Behalf Of Jim Sower
> Sent: Tuesday, October 05, 2004 2:03 PM
> To: Velocity Aircraft Owners and Builders list
> Subject: Re: REFLECTOR: 65VT/ angle-of-attack system
>
>
> Brian Michalk wrote:
> > Okay, now back to canards.  Since the airfoil that stalls is the one
> > that the elevator is mounted, we no longer have a fixed chord.  My AOA
> > sensor that I am planning to grow myself uses a handfull of air
> > pressure sensors feeding into a very small microprocessor.
>
> Rutan had one he designed for (I believe) his Vari-Viggin that was just
> a vane attached to a scale inside the fuselage.  A vane attached to an
> angle sensor would work great and cost practically nothing, is easy to
> calibrate and etc.  How would you calibrate and maintain a "... handful
> of pressure sensors ..."?  I don't even know what that means.  Fighters
> and airliners use a vane on an angular transducer.

Solid state.  No doubt I could rig up the vane as you described; I most
likely will use the vane assembly as the truth for training the neural net.

> > I assume I would also need to feed it an aileron deflection reading.
>
> Aileron deflection?  What for?

Brain fart.  Elevator deflection.
> The traditional vane is good enough for the big guys.  But I'm losing
> track of your objective.  This is starting to sound like the B-2 project
> - the thing has no mission ~ we're just doing it to demonstrate that
> we're *able* to do it.  What exactly is your purpose for all of this?

You are pretty close.  It's cool.  I can brag about it, etc.  Right now, the
tubes are glassed in with vinyl tubing attached.  I estimate I'll be flying
early next year.  I estimate I'll get around to my solid state AOA sensor
maybe five years after that.  The pressure holes are currently primered
over.  The plan is to just paint it.  When I get the itch to play with it,
I'll just drill out the filler.

I have lots of plans for the plane.  Voice recognition tied to everything,
like frequency selection, approach plates, etc.  This is just another part
of the game.  If it all works out, I could see using the AOA data for the
autoland feature.  Hehe.  How about auto-flare?  Should work well once the
GPWS radar system is installed.  Keep the front wheel precisely one foot
above the runway until the canard stalls.

> I don't recall saying anything like that.  I did say that at aft CG, the
> canard will stall at a modest elevator deflection, and at forward CG you
> might need full nose up elevator to stall.

I see this, but it's really counter-intutitive.  Lightly loaded, a small
elevator deflection results in a large force moment.

> fly 80 kts in the turn and gradually decelerate to70 in the groove (or
> 75 if it's gusty and choppy).  Depending on the situation coming across
> the overrun, I will cut the power sooner or later and touch down at 70
> or below (65 and below on a good day).  I get enough AoA input just from
> seeing/feeling how cocked up the airplane is.  It feels a LOT different
> below 70 kts than above, and that's good enough for me.

A friend of mine who shall remain nameless, recently de-laminated a main
gear leg, and asked a lot of people how best to go about repairing it.  The
local Velocity guys get together every Wednesday to talk and have lunch.  He
remarked that he could not think of any particular landing that would have
done the damage.  All of the people at the table whom he has given rides to
piped up, and said they thought they could pinpoint the landing when he
damaged his main gear leg.

Are you saying you normally land at 70?  How much weight is in the front
seats?  What wing/airframe configuration?