----- Original Message -----
From: "josok" <josok-e@ukolo.fi>
Subject: Europa-List: RE: Angle of Attack
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| Hi Ferg and all,
| Sorry for my slow comprehension, please try to be patient with me. I see the
point in Graham's message. In ground effect, the effect of the tailplane being
washed out, and a quick pull to get the tail wheel on the ground. That should
be no problem, if the plane is in the right nose-up attitude eh? That right
attitude,
or angle of attack, is depending on air-speed only, and the sink rate
is governed by weight and power applied, as far as i understood so far. Would
it help to do slow flight at altitude to get an idea of the power needed at
55 knots? Regards, Jos Okhuijsen
Wrong, Jos:
Forgive me (I don't get to say it very often - she won't let me).
Actually the plane flies ONLY because it has the correct angle of attack. It
stalls
at the same ANGLE when the weight is the same, whether it's in ten G pull
at 200 knots or at the top of the loop at 70knots - the angle is always the same
(at the same weight). Add weight and the angle changes.
Therefore we should not be memorising airspeeds for each maoeuvre
near
the stall like we did for years, but watching an angle indicator in the
windshield.
The airspeed will vary with various parameters BUT the angle will stay
the same. The US navy land on carriers ONLY with the AoA indicator. Each weight
and CofG position gives a different angle, but the airspeed might be the
same for other reasons.
You can use airspeed but you should be thinking Angle. For each
angle
there is a 'feel' - she's wobbly, or mushing, or jiggling, or the elevator
gets light, or snatching at the controls or something which tells you by feel
that you are approaching the stall. You want to be at the stall at touchdown but
no earlier! The way to do that is by flying safely as close to the stall as
close to the ground as you can - but it must be approached warily, carefully,
gingerly and in small stages. In my humble opinion the easiest and safest way
is with an accurate A0A indicator
Cheers, Ferg
PS: There are two places to stall your treasure - either at 1 inch or
at 10,000 feet - so stall her high and often to get the 'feel'.
PPS: Happy to discuss further if you want to...........
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