REFLECTOR: Another Velo in the air

[John Abraham]

Dave,

 

SE and XL's should have ailerons drooped 1/8" down.  What your pilot was
experiencing was the leading edge of the ailerons grabbing the air and
pulling on the stick.  You can't find the centering point very well with
this.  The other thing to look at is if the leading edge has any sharp edges
on it.  You want the leading edge to be rounded so it doesn't grab the air.

 

John

 

From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Dennis Martin
Sent: Wednesday, November 30, 2011 10:54 PM
To: Velocity Aircraft Owners and Builders list
Subject: Re: REFLECTOR: Another Velo in the air

 

I hired John Abraham, Velocity Chief Pilot, to conduct my first flights. He
and I spent a couple hours doing fine tuning on the aileron and elevator
rigging. I think you should talk with John about your dutch roll and any
fine tuning you might do to make sure the ailerons are rigged properly. I
also had some nose wheel shimmy - we kept tightening the castle nut until it
went away. We went well past the 15 lbs recommended - perhaps as much as
20-25 lbs. on my fixed gear.

Good luck - I'm sure the factory team can help you figure it out.

Dennis




On Wed, Nov 30, 2011 at 8:42 PM, David Ullman <ullman at robustdecisions.com>
wrote:

N-444DX, an SEFG took to the air for its first flight today after 5+ years
of work.  With Jorge Bujanda's flight,  that makes two planes this week.  I
hired a test pilot, Robin Reid (30,000+ hours in over 300 types of aircraft,
owner of a VarEZ for 5 years, and he flew a Velocity (Thanks Mel Rudin) just
two weeks ago) and I am glad I did.  Most everything worked well which was a
relief since I had been concerned about the engine that I built from a
basket case, brakes heating, and nose wheel shimmy, but none of these were a
problem.  But,I do seem to have a roll control problem that I will work out
over the next couple of days (starting with a call to Velocity tomorrow AM).


It seems that right after take-off Robin experienced a severe Dutch roll
problem whenever he input any aileron control.  This seemed to increase with
speed so he went around a big circle with rudder only and the ailerons
locked neutral. He kept the speed under 120kts and landed at about 100kts.
After taxiing it bask to the hangar I measured the following:

If I push down and let go, both ailerons fare even with the wings.
If I push up on one, it will stay up due to friction about .35" above the
wing when the other is even with its wing.
If I push up hard on one I can flex it to .550"

The reason for this test is the thought that the air loads are pushing them
both up, but this does not explain the Dutch roll (maybe?).

I measured the incidence of both wings at five different locations with an
angle measuring device and found that most values were within a degree of
each other (within the tolerance of the device).

I had a colleague put a resisting force on the ailerons and moved the
control stick and all seemed normal.

One thing I haven't checked is the gap between the wing and the aileron.
This was on spec early on, but there has been paint and other finishing
since then.  I will measure that tomorrow.

Anyone else have a Dutch Roll problem?  I am calling Velocity tomorrow AM to
get their input on this, but other ideas are more than welcome.

David Ullman
N-444DX Velocity
EAA 292 President
david at davidullman.com
541-754-3609


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-- 
All the best,
Dennis

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