REFLECTOR: Aerobatics: Rolling about a point

Wed Feb 23 16:05:01 CST 2005

Hey.  Thanks Alex.  I understand that explanation better.  I know I have
lots to learn about carnards.  I am filing your reply in my "ops" box, but
could do me this last favor? 

Let me say it all back to you.  Let's just say that I am in level,
unaccelerated flight at 185 kts and 5000 feet.  Let's also say to hold all
this constant, I need +2 pitch on my attitude indicator.  If I leave the
power alone, then raise the deck angle to +10, neutralize the elevator, and
than apply full left aileron, then you are saying that the carnard will
continue to pull me "upwards" (that is 90 degrees from a line defined from
cannard wing-tip to wing-tip.)  ...so the to watch me from an in-trail
position I am sort of cork screwing thru the air?

If I understood you right, can't this carnard factor be countered with a tad
of down elevator (and not zero G) so as to keep the nose on a near constant
spot on the horizon, and maybe roll-out back wings level at something near
my entry pitch angle of +2 with little altitude change?

Regards,
Terry

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Alex Balic
Sent: Tuesday, February 22, 2005 12:00 PM
To: Velocity Aircraft Owners and Builders list
Subject: RE: REFLECTOR: Aerobatics: Non center line rudder

Hi Terry-
About the aileron roll maneuver - you need to think about the difference in
lift points on the canard vs. the standard fixed wing- if you see these as
arrows pointing straight up from the fuselage, it is easier to understand -
normally these forces are fighting gravity- in the case of the standard
there is a single large lift vector centered right around the center of
mass, on the canard, there are two lift vectors one in front, and one behind
the center of mass. when you flip the standard up side down, all you need to
do it change the angle of attack, and the lift vector goes through the floor
instead of the top of the fuselage. on the velocity, you can not change the
angle of attack to negative, because it is not set up to have a negative
angle of attack, so even a simple aileron roll will be more like a barrel
roll because the lift vector of the canard will not go negative- it is just
like going through an aileron roll with constant back pressure on the stick
of a standard planform aircraft- so if you are not careful, when you roll
180 and hesitate because the nose is not going where you think it will, then
it tends to perform more of a split S.  The Berkut company had their
demonstrator doing a lot of interesting things (before it crashed) it could
do loops, and some rolls too, but the roll rate was probably double of the
Velocity, so they could get away with more.
Anyway, best to make some friends in the RV community so you can go out on
Saturday morning and get your fix- that is pretty much what I have done!! I
can't really think of any 4 place that beats the Velocity in cross country
comfort- even though the Lancair is faster, it is not as roomy or stable or
quiet......

Alex

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org]On
Behalf Of Terrence Miles
Sent: Sunday, February 20, 2005 12:32 PM
To: alex157 at direcway.com; 'Velocity Aircraft Owners and Builders list'
Subject: RE: REFLECTOR: Aerobatics: Non center line rudder

Alex,

Thanks for the advice.  Actually the RV8 was a contender, but you freeze out
your backseater (in my case wife) on the cross country flights...which is my
principal use.  I don't think the RV10 is stressed for aerobatics.  My only
experience with acro is in a T-38 in 1968 doing about 300 kts.  So it's been
a while, and add to that I have limited time in SEL recips.  Sorry for
sounding so stupid.  I am just trying to get an understanding of
accelerate/decelerate capabilities and more on the flight characteristics of
a carnard.  I am getting the XL so those rudders are way out there and don't
work in tandem.  Thanks for your input.  I get your point about sustained
level inverted flight is different with a cannard design.  

I still don't think of an aileron roll maneuver as ever going negative.  It
you start w/ the nose up +10 from level I can't invision losing altitude
either.  About the cuban eight...but I would want to execute
constant-heading half rolls without the airplane fishtailing due to any
possibly needed non-centerline rudder inputs to compenstate for torque
influences w/ larger throttle changes.  Is this an issue?  Have you got a
comment there?  As a small aside, my Saturday acro occasionss would not
include any intentional neg g's!  Yuk.   Thanks for the welcome and for
getting back when you have a minute.  
Terry

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Alex Balic
Sent: Sunday, February 20, 2005 12:01 AM
To: Velocity Aircraft Owners and Builders list
Subject: RE: REFLECTOR: WANTED: Acro contacts

Hey Terry,
Welcome to the reflector!
About the velocity doing aerobatics, the canard design in general, and the
Velocity in particular does not lend itself well to any negative G maneuvers
due to the load being shared by both the wing and the canard, in most other
planforms, the wing does all of the carrying, so if you want to go inverted,
you just need to fly the wing at a positive angle of attack with the ground.
If you try a roll with the velocity, you might pull it off, some have, but
chances are, as soon as you go inverted, you will find that there  isn't
enough down elevator to keep the nose level, and the canard is going to pull
you really hard toward the center of the earth, and you will end up doing an
un-commanded split-s.  If you like doing Aerobatics, even Saturday morning
style, you would be better off in an RV which is a blast to fly that way. 

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org]On
Behalf Of Terrence Miles
Sent: Saturday, February 19, 2005 9:10 PM
To: 'Velocity Aircraft Owners and Builders list'
Subject: RE: REFLECTOR: WANTED: Acro contacts

Hi,

I should enjoy my ignoble status while it lasts. I have the honor to

be the very newest running nose, wide-eyed kid on the block. The kit

gets delivered in a month or so.   In fact I can't seem to get my own email
out (reflector at tbvf.org) so I had to use the reply function to get this on
the Reflector.  Sorry Dave.  

I've got a quick kind survey question on acro. I bought the V kit for xc
reasons, but are any of you out there doing cuban eights? Is the airplane
any good as an acro platform? I know it can take the G loading...but what
about roll rate with rudder deflection not centerline?   Rudder and aileron
size and effectiveness? I didn't understand a thread in the archives about
dishing out of an aileron roll...did they mean like barrel roll?  If you
raise the nose just a little and bang the stick to the left won't it just
roll around a point w/ very little if any heading change, as opposed to
barrel roll where the flight path simulates a corkscrew as opposed to a
spinning top?  

Are there and VNE problems w/ say doing a simple split S and no speed brake?
The only acro I have done is in jets, so I am a little lost on this stuff.
Has anyone developed any target speeds/power settings for continuous cuban
eights?  Anybody doing in trail formation stuff that I could talk to off
line? 

Thanks for helping with this. When I become more informed myself, I hope to
somehow return the favor down line.

Terry

Now back to your regularly scheduled program....

-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of davedent at comcast.net
Sent: Saturday, February 19, 2005 7:18 PM
To: rwhenderson at msn.com; Velocity Aircraft Owners and Builders list
Subject: Re: REFLECTOR: WANTED: West Coast CFI (SF Bay Area)

Check with Steve Murphy.  He gave me my company check ride.  Also has
checked out many others.  He will charge you a small fee for the check ride
and light fees for the training in your plane.  Plus his cost for fuel to
come to your airport.  He live up in the Reno area.  
He had no problem with me seeing I had 1500 hrs in  canards before flying my
Velocity.  I now have 60 hrs on it since last March.  
I'm not a CFI but if you need time in a Velocity before you fly yours come
by and we can make it happen. 
Dave N32XL
LVK
-------------- Original message -------------- 

> Anyone know any good instructors on the West coast? I'm looking for a CFI 
> with Velocity experience in the San Francisco Area for an insurance check 
> ride & sign-off. 
> 
> Must be a CFI w/ at least 50hrs in a Velocity (SUV preferred, but not 
> required). Any referrals would be greatly appreciated! 
> 
> 
> Thanks, 
> 
> - Rob Henderson 
> rwhenderson at msn.com 
> 
> 
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