Tuesday, April 20, 2010

Is the canard incidence correct?


I have a Cozy III with the GU canard, the empty weight of my plane is 1060 pounds, it has a rotation speed of 85 KTIAS. In flight the canard is angled down, not reflexed up.

These pictures are with me flying solo in cruise likely 6-10k feet at 150 KTIAS.

This chart is to show the angle of the elevator

Excerpt from Cozy newsletter:

From: Wayne Hicks
Subject: COZY: FW: Cozy IV incidence settings
Date: Sun, 24 Dec 2000 10:03:39 -0500

-----Original Message-----
From: Nat Puffer
To: Wayne Hicks
Sent: 12/23/00 10:18 AM
Subject: Re: Cozy IV incidence settings

Dear Wayne,
Thank you for calling this mis-information to my attention. Perry Mick
wrong, and please publish a correction on the canard aviator's list.
The canard on the Cozy has always been set at a higher angle of
than on the Long EZ. This was true of the GU canard on the Cozy III,
Atkinson's drawings for the Roncz canard on the Cozy III, and the Roncz
canard on the Cozy Mark IV. The reason for the greater angle of
is to off-set the lift generated by the wider fuselage on the Cozy III
IV as compared to the Long EZ, and prevent the angle of attack becoming
great enough to stall out the main wing.
In the first edition Mark IV plans, it was specified that the top of the
elevator travel checking template "G" should be level when the longerons
were level, and this provided the extra canard incidence as compared to
Long EZ. In 1991, after the plans were printed but before anyone was
flying, it was discovered that the canard contour checking template "F"
not agree with template G, and if builders used template "F" to set the
incidence, it would not be correct. So a design correction was published
the October '91 Newsletter 35, page 6, to change the top of template "F"
agree with template "G". In the 2nd edition plans, template "F" was
to agree with template "G" before they were printed, so either template
could be used to set the canard angle of incidence, and it would be
correct. In Newsletter #56, page 5, a chart was published so that
could determine by elevator position whether their canard was set at the
correct angle of incidence, and builders were instructed to add this to
their Owner's Manual, page 46, and make this determination before
their flight envelope. Perry Mick's last newsletter was #53. The Cozy
construction manuals state that the plans are obsolete unless updated
corrections published in the newsletters.
We have discussed the importance of having the correct angle of
on the canard many times in our newsletters, and will continue
it, because the angle of incidence must be correct to have the right
qualities and the protection against main wing stall.
To summarize; template "G" has always been correct in both the 1st and
edition plans. Template "F" was not correct in 1st edition plans, but
builders were instructed to correct it in Newsletter #35 in 1991. No
correction is need in 2nd edition plans, because both template "F" and
template "G" were and are in agreement.
Best regards,
PS: Maybe you should republish it to the Cozy_Builders as well
> From: Wayne Hicks
> To: 'Puffer, Nat'
> Subject: FW: Cozy IV incidence settings
> Date: Saturday, December 23, 2000 9:20 AM
> Happy Holiday!
> Nat:
> This was posted to the Canard Aviator's Group.
> I'm forwarding it to you in case you don't subscribe to canard
> I've always thought that the Cozy IV canard templates were all at zero
> degrees incidence, and if that's true, then this "misinformation"
> be corrected before someone calls it fact? :-)
> ================================
> Wayne Hicks
> Cozy IV Plans #678, Chapter 19 Wings
> http://www.geocities.com/yosemite/falls/2027
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> -----Original Message-----
> From: Perry Mick [mailto:pjmick@viclink.com]
> Sent: Friday, December 22, 2000 10:18 PM
> To: Canard Aviators
> Subject: [c-a] Re: Pitch Trim
> [The Canard Aviators's Mailing list]
> Just discovered something interesting. When the Cozy IV came out with
> Roncz canard, it had the
> same canard incidence as the Long-EZ. I know this because I just
> Cozy IV incidence
> checking template "F" with the Long-EZ template and they are the same.

> In October 1996 a canard template "G" was introduced for the Cozy IV,
> had 0.83 degrees more
> incidence on the canard than "F".
> --
> Perry J. Mick
> Duckt N7XR
> http://www.ductedfan.com
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