>
> This is not for the ex-Naval test pilots or 100-series fighter
> types but a short topic for the 500-hour private drivers among us.
>
Its interesting to note that you say this, then mention memorizing the 30, 60
and 90 degree bank angle conversions, and the airshows where stalls are
worrying you. I guess we are just lucky here in the US where there is almost
always more than ample runway space and its easy to be laxidasical about our
approach speeds. An ASI is all I have needed so far, but I haven't been
landing on aircraft carriers or 400m farm strips. I suppose if you are going
to be making 90 bank tuns near the ground or pushing the landing distance to
its limits, things are different. In that case, have you considered doing
what the Navy does.. adding rudder shakers? (based on AOA, they vibrate the
rudders on eminent stall)
I say this almost in jest, but they really are the cat's meow. No need to be
glued to a gauge and they give unique physiologic inputs for impending stall.
There are so many noises and lights in the cockpit, but when that rudder pedal
shakes.... I'm sure it would be a simple mod to take the output from a
standard AOA indicator and run it to a small motor on the rudder pedals.
:-) Not to mention that this would be the first of its kind in an
experimental!
David Leonard
Stuck on Diego Garcia
by rly-ya04.mx.aol.com (8.8.8/8.8.5/AOL-4.0.0)
with ESMTP id VAA08761;
Date: Tue, 29 Dec 1998 11:01:27 +0000
From: Fergus Kyle <fkyle@bigwave.ca>
Subject: The last hundred feet
Cheers! and Happy New Year!
I know this topic has been breached several times but, having noted
the penchant for losing lift due to loss of airspeed control, am bent on
pronouncing for a further study of Angle of Attack instruments.
This is not for the ex-Naval test pilots or 100-series fighter
types but a short topic for the 500-hour private drivers among us.
The airspeed indicator has been with us all along as the prime tool
for lift control. Some have been very effective over the years. However
the primary sensor should really be a lift/drag comparator because IT is
the basic guide to what the wing is doing. Having come once or twice to
shaving the stall region too closely at airshows or on tests, I can say
that nothing raises the hair on the back of the neck (nor promotes hot
sticky nightmares)better than realising you've used up your lifetime
ration of slow lift hours! Amother thing this does is to promote many
hours of contemplation.
In the course of those hours, and having had the experience of
"alpha-flying" - that is flying by reference to the angle of attack
indicator instead of the airspeed - I am convinced that more of us need
to do this. It has saved my buns twice now.
Instead of memorising the 30,45 and 60deg bank factors on 'stall
speed' (and density altitude and all those other factors), one need only
consult the alpha angle to know how to control the lift/drag ratio and
thus the proper approach attitude under ALL conditions. This holds true
for best endurance, best rate of climb, best CofG, best this, best that.
The alpha indicator is to lift control as GPS is to the alidade or
octant.
There are a number of alpha systems out there and each should be
evaluated before choosing. The airspeed indicator is fine for cruise
control but is IMHO a secondary needle on final approach and landing.
Else why would Lockheed have chosen alpha as the prime parameter for the
TriStar Direct Lift Control system and landing variable? Looking at all
those heavy=lift accidents in recent years, I cannot help but wonder why
other makers haven't addopted the same principle.
If you're at the wing-building stage, please consider the
implications of installing this great device.
Happy Landings for 1999,
Ferg (#A064)
P.S: No, I'm not involved in ANY way with providing them!
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