Today's Message Index:
----------------------
1. 11:06 AM - Re: Outrigger wheel fork (Kevin Klinefelter)
2. 01:02 PM - Re: Effects of Flaps and Ailerons on Pitch Trim (JonSmith)
3. 01:51 PM - Re: Re: Effects of Flaps and Ailerons on Pitch Trim (Raimo Toivio)
4. 02:54 PM - Trim and such (Fergus Kyle)
5. 03:31 PM - XS Wing/Fuse Fairings on a Classic?? (Tony Renshaw)
6. 06:26 PM - Re: Outrigger wheel fork (Fred Klein)
Message 1
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| Subject: | Re: Outrigger wheel fork |
Erich,
Your fully retracting outriggers into the wings are very slick! And the
wheel forks, so simple. I bet they are a lot lighter than the original
wheel and fork.
Kevin
N211KA XS Mono 914
Message 2
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| Subject: | Re: Effects of Flaps and Ailerons on Pitch Trim |
Hi Jos & Graham, My theory about the tailplane was based on the principle of a
FULLY aerodynamically balanced "all moving" tailplane, this being the perfect
situation for efficiency. (Jos - MY interpretation of "aerodynamically balanced"
being specifically related to an "all moving" tailplane that is not deflected
at all from it's current position by it's relative airflow, including any changes
to that airflow, ie the center or point of the lifting force (downforce)
generated by the tailplane acts through the pivot (torque tube))
However, IF Graham's info about the C of L being deliberately designed to be NOT
quite acting through the pivot (due to this short period oscillation - whatever
that is!) is true, and I am very pleased and interested to bow to his most
extensive experience of the Europa development and learn about this, then this
means that the Europa tailplane is not quite perfectly aerodynamically balanced.
Thus, unless the Angle of Attack of the tailplane is at any time zero (most
unlikely) then a small tab deflection in the relevant direction would be required
to counter the rotating force created on the tailplane by the airflow.
(I would class this as another "unwanted" rotational force as in my previous
text under variances!). This rotating force - and the corresponding amount of
tab deflection required to offset it to maintain trimmed flight would vary slightly
depending on the relative airflow to the tailplane and the corresponding
amount of lift (downforce) being generated. This aerodynamic imbalance of
the tailplane must I feel only be slight - the whole downforce generated by the
tail is fairly small and is needed just to balance the wing's own imbalance
of forces.
(Question - WHY then are some people's tabs completely flush in steady trimmed
flight.....?!)
This aside though, I still fully stand by my comments of how the tailplane, especially
the tabs work in principle. The tabs, when trimmed by the pilot correctly,
hold the tailplane in the desired position as set by the elevator control.
The tabs would ideally be flush (fully aerodynamically balanced tailplane)
but will have a permanent, slightly variable deflection if Graham's info on the
tailplane not being fully aerodynamically balanced is true (as I'm sure it
is..!)
Jos - of course the trim control is necessary - vital in fact to keep the elevator
control where the pilot wants it and to provide "feel" or "weight" (the anti-trim
part as you call it) to the stick to stop the pilot "breaking things"
as you most eloquently put it! But I think that without trim tabs fitted the
elevator control would be VERY LIGHT to move (not heavy) throughout the entire
range, dangerously so without extreme care. A perfectly aerodynamically balanced
(all moving!) tailplane without trim tabs fitted would be completely without
weight or feel at all throughout the entire elevator range (most undesirable).
The trim tabs we have are very powerful being so far from the torque tube
and if set even slightly out of the correct trimmed position would make the
stick very heavy to hold in position. This of course is not force generated by
the tailplane itself, rather the (rotating) force being applied to the tailplane
by the incorrectly set trim (tabs).
Best Regards, Jon
(Sorry about the length again!)
--------
G-TERN
Classic Mono
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=298854#298854
Message 3
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| Subject: | Re: Effects of Flaps and Ailerons on Pitch Trim |
This is what I think this topic shortly:
1) we could fix permanently the tabs and stop
trimming but then we have to
accept we loose also anti-servo-function which is
necessary to generate some pilots stick forces.
Flying with zero pitch forces by stick would be
nauseous and
dangerous.
2) trimming function is there just to zero trim
tabsanti-servo
loads when tailplanes are in their desidered
position = when trimming pilot is in fact
in-lining the
tabs with the tailplanes to zero the stick forces.
Stick loads means the tabs must be deflected more
or less, no
stick loads means the tabs are in-lined with
tailplanes = the plane is trimmed.
3) if the trim tabs are slightly deflected when
the plane is trimmed and there are no stick
forces, it means some unperfection with
tailplanes shape (foam structure, no NG factory
made).
4) " aerodynamically balanced " tailplanes = the
forces which try to turn the tailplanes clockwise
are always equal with the forces which try to turn
them anticlockwise.
That is why they could float in any position any
time (without anti-servo function or pilots hand
which keeps the stick steady).
Frans, do you now have more photos with varying
speeds and CofGs ?
Raimo
--------------------------------------------------
From: "JonSmith" <jonsmitheuropa@tiscali.co.uk>
Sent: Tuesday, May 25, 2010 11:00 PM
Subject: Europa-List: Re: Effects of Flaps and
Ailerons on Pitch Trim
> <jonsmitheuropa@tiscali.co.uk>
>
> Hi Jos & Graham, My theory about the tailplane
> was based on the principle of a FULLY
> aerodynamically balanced "all moving" tailplane,
> this being the perfect situation for efficiency.
> (Jos - MY interpretation of "aerodynamically
> balanced" being specifically related to an "all
> moving" tailplane that is not deflected at all
> from it's current position by it's relative
> airflow, including any changes to that airflow,
> ie the center or point of the lifting force
> (downforce) generated by the tailplane acts
> through the pivot (torque tube))
>
> However, IF Graham's info about the C of L being
> deliberately designed to be NOT quite acting
> through the pivot (due to this short period
> oscillation - whatever that is!) is true, and I
> am very pleased and interested to bow to his
> most extensive experience of the Europa
> development and learn about this, then this
> means that the Europa tailplane is not quite
> perfectly aerodynamically balanced. Thus,
> unless the Angle of Attack of the tailplane is
> at any time zero (most unlikely) then a small
> tab deflection in the relevant direction would
> be required to counter the rotating force
> created on the tailplane by the airflow. (I
> would class this as another "unwanted"
> rotational force as in my previous text under
> variances!). This rotating force - and the
> corresponding amount of tab deflection required
> to offset it to maintain trimmed flight would
> vary slightly depending on the relative airflow
> to the tailplane and the corresponding amount of
> lift (downforce) being generated. This!
> aerodynamic imbalance of the tailplane must I
> feel only be slight - the whole downforce
> generated by the tail is fairly small and is
> needed just to balance the wing's own imbalance
> of forces.
> (Question - WHY then are some people's tabs
> completely flush in steady trimmed
> flight.....?!)
>
> This aside though, I still fully stand by my
> comments of how the tailplane, especially the
> tabs work in principle. The tabs, when trimmed
> by the pilot correctly, hold the tailplane in
> the desired position as set by the elevator
> control. The tabs would ideally be flush (fully
> aerodynamically balanced tailplane) but will
> have a permanent, slightly variable deflection
> if Graham's info on the tailplane not being
> fully aerodynamically balanced is true (as I'm
> sure it is..!)
>
> Jos - of course the trim control is necessary -
> vital in fact to keep the elevator control where
> the pilot wants it and to provide "feel" or
> "weight" (the anti-trim part as you call it) to
> the stick to stop the pilot "breaking things" as
> you most eloquently put it! But I think that
> without trim tabs fitted the elevator control
> would be VERY LIGHT to move (not heavy)
> throughout the entire range, dangerously so
> without extreme care. A perfectly
> aerodynamically balanced (all moving!) tailplane
> without trim tabs fitted would be completely
> without weight or feel at all throughout the
> entire elevator range (most undesirable). The
> trim tabs we have are very powerful being so far
> from the torque tube and if set even slightly
> out of the correct trimmed position would make
> the stick very heavy to hold in position. This
> of course is not force generated by the
> tailplane itself, rather the (rotating) force
> being applied to the tailplane by the
> incorrectly set trim (tabs).
> Best Regards, Jon
> (Sorry about the length again!)
>
> --------
> G-TERN
> Classic Mono
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=298854#298854
>
>
> browse
> Un/Subscription,
> Chat, FAQ,
> http://www.matronics.com/Navigator?Europa-List
> Web Forums!
> List Admin.
>
>
>
Message 4
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I admire the authors of that exchange of views regarding the tabs on
the Europa stabilator. I've had enough training in aerodynamics (ca.1950)
and forgotten most - to appreciate the mental shuttling required to design
and forestall the effects of the air on the controls throughout the travel
range.
Ivan and his associates certainly have my respect. It DOES seem to
me that disregarding inaccurate shape, inappropriate weight balance or
excess system friction, hands off trim should show the tabs aligned with the
stab. At any rate if not warned otherwise, I'll fuss if the tabs aren't
aligned if/when flies.........
A064 is now anent C-FFGG.
cheers, Ferg
Message 5
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| Subject: | XS Wing/Fuse Fairings on a Classic?? |
Gidday,
I am wondering if the profile of the XS is much different from the classic, meaning
the Europa factory supplied fairings won't fit properly?? I can't imagine
there is much if any difference, as I imagine the XS was moulded off a good classic
wing, but I don't know specifically, only surmising. So, if anyone can
help me out I'd appreciate it.
Reg
Tony Renshaw
Sydney Aussie
Message 6
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| Subject: | Re: Outrigger wheel fork |
On May 25, 2010, at 5:50 AM, Kevin Klinefelter wrote:
> Erich,
> Your fully retracting outriggers into the wings are very slick! And
> the wheel forks, so simple.
Erich...I second that...any pixs of the "doors"?
Fred
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