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Re: Europa-List: monowheel positon of stab and aileron

Subject: Re: Europa-List: monowheel positon of stab and aileron
From: Ami McFadyean <ami@mcfadyean.freeserve.co.uk>
Date: Wed, 10 Dec 2003 20:35:27

Yes, not forgetting to mention that Martin Stoner's problem was one of
geometry.

That is, the outriggers would do a very good job of stabilising the wings
(when on the ground) IF the axle line of the outriggers were coincident or
even ahead of the main wheel axle line.
As they are not, then under the action of a cross camber and/or quartering
tail gust and/or exacerbated by braking, the a/c can tip to the 11 o'clock
or 1 o'clock positions more easily than to the 12 o'clock position.

Monowheels are in good company though. The Jabiru with its short-coupled and
narrow-tracked TRICYCLE undercarriage can do the same. Even when stationary
in a power-check!


Duncan McF.
----- Original Message -----
From: "Fergus Kyle" <VE3LVO@rac.ca>
Subject: Europa-List: monowheel positon of stab and aileron


>
> >Subject: Europa-List: Monowheel position of elevator and aileron?
> >Sorry to bother you with this question, figured would get an easy answer
> from the >group.
> > NOT!
> > Curious
> > When taxing a monowheel with a 20 knot quartering tailwind, lets say
from
> the left, do
> >you keep the elevator full forward and the stick full deflected to the
> right?
>         There IS a difference between an elevator and a stabilator. The
> first                 changes the shape of the control surface, such that
a
> down elevator curves     the elevator/stabilizer control making it more
> sensitive to unwanted wind             vagueries. The stabilator does not
> change shape so is not as sensitive (say     to tipping up the tail from a
> tailwind). Judging the severity of the effect is a         Command
decision
> and comes mostly from experience
>
> >Since the Europa has outriggers, for all I know dragging the downwind
> outrigger does >more good in keeping things straight than trying to keep
the
> upwind wing down?
>         Because of outriggers, the problem of preventing wing-up events
> tends to     be less critical. Nevertheless it is good practice to select
up
> aileron into wind     o spoil any potential lifting tendency. All of this
> of course depends on the         strength of the gust/wind. I would
believe
> any sidewind meeting a lifting             surface would tend to reduce
> directional control, even slightly.
>
> >As far as the elevator, for all i know perhaps the huge prop spinning
puts
> flow from >front to back instead of back to front?
>         I dont believe (with a tailwind) you will want to add to its
effect
> by                 increasing speed/power with the prop. The only time to
> blast with power is to     correct a sudden swing - and then only for an
> instant. This is a neglected         practice, but a vital one in a Boeing
> Stearman. Otherwise, throttle                     back.
>
> >I honest don't know, but my guess is full forward and full to the right.
>         I wont do that. You are reducing the one thing giving directional
> control -     the tailwheel. Besides, I dont think theres a hard and fast
> rule for any control     position. If you sense a threatening tailwind,
> stick full back because the stab     will be stalled and you may be adding
> weight to the tailwheel.
>     Stick to the LEFT (port) if the wind is there. Stick into wind to dump
> lift on         that side (reduce camber).
>
>         Of course, these remarks are a personal attitude and open to any
> correction - I may have misspoken.
>          a personal experience. I shared a Stearman belonging to He in
> the Back Seat, a naval cadet grown to senior years and open to gossip and
> hearsay (much as do sailors referring to local knowledge as a valued
> item). When I questioned him on a burp in the Continental on final to
> Mitchell SD, he replied, the old guys tell me it clears its throat every
> once in a while. When I insisted on asking the mechanic, he found one
> magneto arm cracked and taking on moisture, and the other even worse! We
> were there three days till the parts arrived - BUT we had overflown Lake
> Ontario and northern NY (trees) enroute. No engine clears its throat.
> Ferg
> A064




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