REFLECTOR: electrical sys design
Alex Balic
alex157 at direcway.com
Thu Feb 24 17:12:55 CST 2005
MessageTerry-
You will gain a ton of useful information from Bob- he know his stuff- he
doesn't mind hearing/debating any other viewpoints either- I went to his
seminar 2 years ago, it was invaluable- one thing though- someone in the
group needs to keep him focused on the subject at hand- in our group things
tended to go off topic a lot- which was fine if we were spending a week with
him, but at the 2 day seminar, I needed to get as much pertinent info as I
could. Great door prizes too- I got a really nice set of PDIG crimpers, and
someone got a small handheld GPS too!
-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org]On
Behalf Of Terrence Miles
Sent: Thursday, February 24, 2005 1:05 PM
To: 'Velocity Aircraft Owners and Builders list'
Subject: RE: REFLECTOR: electrical sys design
Jim, Greg, Alex,
Thanks for the stories, the great explanation and the good advice. The
Reflector is a great reference. Believe me, I will keep all this in mind
and build my skills and experience slowly...and I follow the point about the
Velo's slow roll rate make RV-8 a more exciting aerobatic platform. I too
have XC as my primary use. That said, I gotta son who flew the F-18 and
well... we never been "blue side down" together yet. I'll take my time
learning. Don't worry. The T-38 had very stubby wings and giant
ailerons...this is going to be a lot different, I know.
New topic: I am headed to Bob Nuckol's AeroElectric seminar in about a
week. It will be just outside of St. Louis. Anybody building down there?
I plan to ask him about the advantages and feasibilities of two 40-amp
alternators, versus say a 60-amp and a 25-amp and ramifications on engine
build up/instalation that this choice entails. Also the regards internal
regulators versus external regulars and advantages for cockpit
warnings/indications. I am going w/ the XL-RG-5 and likely the LY 540 K and
being only 150 lbs, I already decided on two batts for CG!!
Anybody else have an electrical question or two that I can ask for the
group?
Terry
-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Jim Sower
Sent: Wednesday, February 23, 2005 7:53 PM
To: Velocity Aircraft Owners and Builders list
Subject: Re: REFLECTOR: Aerobatics: Rolling about a point
Terry,
Aileron rolls in my experience are positive G maneuvers. A full
acrobatic airplane can do aileron rolls quite nicely without negative G (for
the most part - like except for demos of multiple multiple rolls with no
altitude change). Like, by the time the airplane figures out that the nose
should be dropping, you're not upside down any more. The problem with the
Velocity is A) limited roll authority, and B) large lateral (rolling)
inertia that has to be overcome result in painfully slow roll rates. One
way to compensate for this is: start level at your entry speed (you
mentioned 185 kias), yank in a lot of back stick (4-5G?) and snap your nose
up 10* or more before you start the maneuver. You don't have to climb, just
establish your velocity vector at least 10* up. Then put in all the stick
and rudder you have. The swept wings of the Velocity will help with your
roll rate to the extent you have positive G and full rudder. If you're
heading uphill (even if your altitude hasn't changed yet) you are in a
position to scoop out a good bit without losing all that much altitude.
Starting anything remotely like level, the sorry roll rate and high inertia
of the Velocity will cause you to scoop out so hell wouldn't have it, so be
sure to be going smartly uphill when you start. Whatever else happens, once
you start DON'T STOP (unless you fully intend to do a split-S).
By way of perspective, military fighters do not have inverted fuel or
oil. The ones I flew had around 10 sec of inverted fuel and no oil at all.
A great deal of ACM maneuvering with swept wing fighters involves "rudder
rolls" which as the name implies uses a lot more rudder than aileron. Demo
planes (Blues, T-Birds, etc.) have very elaborate fixes to give them full
inverted fuel and oil.
By NO means do any rolls below 4000 - 5000 AGL until you've done a LOT
of them at high altitude. Even when you do it as best the airplane is able
to, it's so awkward and sluggish that it isn't even any fun.
More better, take Alex's advice - do this stuff in an airplane that can
do it right ... Jim S.
Terrence Miles wrote:
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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