To tie Fred's comments about false horizons to the thread on mountain
flying, think about the situation when you descend into a mountain valley.
As you drop below the ridge line, you lose a useful horizon reference. If
you keep the nose on the jagged line between ridge top and sky, your nose
will get higher and higher as you continue the decent - you have to point
the nose at some indeterminate point on the sides of the valley to maintain
the desired airspeed and prevent a stall.

This is a subtitle trap that snares many 'flatland' pilots on their first
mountain trip - usually in an overloaded Cessna 172 right after takeoff.
These pilots have learned to use the familiar, reliable horizon line at
their home airports. It's always there and they have always relied heavily
on it. Take it away, and their pilot skills evaporate.

It's quite possible to fly pitch attitude with reference to the airspeed
indicator but that's a instrument rated pilot "partial panel" trick and
most pilots either aren't trained to do it or aren't good at it.

An AOA indicator solves the problem nicely.


Bill Daniels


"fredsez" wrote in message
...
So many good ideas on AoA. Much thought and real considerationhas
have been expressed. Something (A-HA!) came to mind.
Visual indicators!
Back in 1901, or some where about then, I flew a 1-26 to a really
high altitude. I had left the area of recognizable land and decided to
look at the ground and figure out where I was. Before I had that good
idea, I was looking right at the sun, well above the horizon.
Looking down, all I could see was black! The land was in definate
NIGHT TIME!
I have always been a FLAT EARTH person. I have also watched the sun go
around the earth! I get up with the sun in the east and go to bed with
it setting in the west.
From umpteen thousand ft, I spotted a little (very little) strip of
light. There was where I decided they would find my body. I opened the
airbrakes and managed to find a lighted strip of asphalt at an
intersection in Nevada.
The rest of the story is interesting (to me) but has little to do
with AoA.

At my air strip, when you turn onto base leg, the ground rises, With
the horizon high, pilots tend to raise the nose to see a normal sight
picture. Airspeed slows,.. things don't look right and some push
rudder to point the nose down the runway...or at the tie-down area.

At thousands of ft in the air, the horizon looks low relative to the
instrument panel. At pattern altitude, the horizon looks higher and
may lead a pilot to raise the nose, losing airspeed in the turn onto
final. I need to make changes. What should I do? Maybe reverse the
pattern and let pilots see the lower horizon and tend to make them let
the nose down? Maybe I ought to go to bed and let things be as they
will be.
Fred.