Hi JR.

On Aug 5, 12:22 am, "JRWeiss" wrote:
Ken S. Tucker wrote:
Referring to sims, I found the AoA indicator of scientific interest
to measure airfoil performance, but in shooting landings I relied
on the IAS (knots/hr) and vertical airspeed indicator(feet/minute),
those together give a rough idea of angle of descent, and one
then gets a feeling of AoA from pitch.

Yes, you can get a "feel" of AOA from all that, but not enough to fly
AOA with the accuracy required in modern carrier operations. A half
degree of pitch or a decel/accel trend that you don't see in time could
be the difference between a safe landing and a bolter or worse.

BTW, IAS is measured in knots, not knots/hr. A knot is a nautical
mile/hour, so "knots/hour" would be an acceleration, not a velocity.

What might be considered is an instrument that can provide all
that info in nice clear form on single gauge at a glance, let's
design it.

Can't do it; there are too many different types of measurements to be
made and displayed. While a velocity vector pointer on a HUD may give
a good portion of it, speed is missing...

Indicator-instrumentation is subjective, so I'll shoot from the hip.

Let DV be rate of ascent, vertically directed, with a length.

Let IAS be Indicated AirSpeed be a vector with length and direction.
The IAS vector is a hypotenuse, let HAS be Horizotal AirSpeed then

IAS^2 = DV^2 + HAS^2

forms a right angle triangle. The IAS and DV come from standard
measurements and the HAS is readily derived, so we have
Ascent Angle embodied in the IAS vector, (pardon the math).

Next, we include Pitch, that is a measurement derived from the
artifical horizon. From those the AoA is

AoA = Ascent Angle - Pitch.

On an actual display, suppose we display the IAS as a vector,
with lengths that are colored green, yellow, red, with red-yellow
demarking a near stall, as well as the Pitch vector, then at the
origin of those displayed vectors, you can print out AoA to .1 degree
accuracy, sufficient for most pilots.

In my experience, some guys like dials (like clock hands) others
like digital, that was a hassle when Volt-Ohm meters went digital,
lots of arguments. Personally I like both. The meter provides a
sense of rate of change, but the digital provides precison at a
glance, so I think the 'AoA' indicator ought to be designed to
reflect those concerns and conditions.

One question, would you want a g-force indicator?
Ken