REFLECTOR: Take Off Performance

[Tom Martino]

When I first looked into Velocities, I realized that a 200 Horsepower
Velocity is a two-place plane at best.  That is why I went with a IO-540
(generating 310 hsp) on a 173RG Elite.  If the truth be told ... I still
don't think it is an adequate 4 place.
 
When I compare the canard to my other plane - A SR22 Cirrus (also 310
horsepower) - you soon realize that the Velocity is a ground-lover.
 
My field is at 5500 ft and I have a four-blade MT prop.
 
The Cirrus is much heavier ... but jumps off the ground compared to the
Velocity.
 
Once flying ... the performance is about equal.
 
Is it the canard that makes it sluggish on take-off?  That's the only
tin I can surmise.
 
-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of NMFlyer1 at aol.com
Sent: Sunday, April 09, 2006 9:11 AM
To: reflector at tvbf.org
Subject: Re: REFLECTOR: Take Off Performance
 
When I went to the last Texas Velocity event in TKI, I was amazed at how
much runway Velocities took to get off the ground. It wasn't very hot
that weekend, and the field elevation was much lower than here in New
Mexico.  That weekend was an eye opener for me, and caused me to go with
my current engine choice (340 HP 4.3L, Aluminum V-6 Chevy). 
 
Since my field elevation is 4800 MSL, density altitude (DA) is always a
concern. On a summer day out here, about 25% of your horsepower is gone,
just to DA, and that doesn't include the effects on prop and wings. If
had put a 200 HP IO-360 in my 173, I would be trying to take off from a
4300' runway, in a canard, with 150HP (on a good day) high and hot,...
NOT a good idea... just ask Scott... he's been in here a couple times.
Notice he is changing engines in his V also. 
 
So my plan for high DA takeoffs here has many parts: 
 
    More Horsepower!!! That should get me to takeoff speed much faster.
 
    Lots of torque, and a huge 76" 3-blade constant speed prop.
    
    The 173 Wing, for slower T/O & Landing speeds, and better high
altitude performance.
 
    I left the Elevator cuffs off. Am putting the VG's on. 
 
    I reworked the rudders. I have about 2.5" deflection before the
brakes touch.. and over         5.5" total rudder travel. That should
help on takeoff and reduce brake use on takeoff &         crosswinds. 
 
    
Wish me luck. I pick up my ceramic coated exhaust tomorrow and finish up
the engine monitor wiring this week. Pretty close to engine start...
finally. 
 
Kurt 
 
 
 
 
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