AoA keep it going!

If you are too busy on landing to watch an AoA indicator you must
therefore be too busy to watch an airspeed indicator. I don't have much
time in gliders but in my powered plane, I usually glance at the ASI as
I level the wings on final, then I just use visual (and wind noise)
references to make the landing with an occasional glance at ASI as I
start the roundout and flare. I think the AoA would be most useful at
altitude when flying a tight spiral in a column of lift...

Scott


Ian wrote:

On 17 Dec, 20:37, "Bill Daniels" bildan@comcast-dot-net wrote:


I'd love to have a quality AOA indicator to make those landings easier and
safer.


I generally find that my attention is fully occupied while landing. If
I had an AoA indicator, I would have to take attention away from
something else to look at it (I always have the audio vario and radio
off for the final approach). Would an AoA also indicator free up some
of my attention, and if so, from what?

Ian

--
Scott
http://corbenflyer.tripod.com/
Gotta Fly or Gonna Die
Building RV-4 (Super Slow Build Version)

On Wed, 19 Dec 2007 13:53:20 -0800 (PST), Ian
wrote:


And can you imagine what would happen with a stall warning sounder?
Pilots used to flying with gear-down warnings would anxiously check he
undercarriage lever ... subconsciously pulling back to give themselves
a bit more time ...

Correct.

I once had the pleasure to see a live performance of one of the oldest
aircraft-related jokes:
Belly landing of our ASW-24. One could hear the gear warning all over
the airfield. Pilot got out and commented that he was wondering where
all that noise was suddenly coming from during his final approach.


Bye
Andreas

Scott wrote:

Because an AoA gauge responds directly with "relative wind"
Airspeed indicators respond to ram air pressure measured against static
pressure. Have you ever noticed that your airspeed indicator seems to
read higher in the winter due to denser air (assuming you live in a
climate with vastly different temps between summer and winter). Also,
have you ever noticed your airspeed indicator reads lower at higher
altitudes (due to less dense air)? AoA is accurate regardless of the
above mentioned differences.

Do you mean "for the same power setting"? Engines tend to produce more
power in cold temperatures than hot, so perhaps that would explain it.
In glider, what you might notice is your ground speed is lower (e.g.,
when landing) in the winter than summer, even though you have the same
airspeed indication.

It's not a problem - it's a benefit!

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

WOW, What a thread!
The only AoA's that I'm familiar with are huge wedge
shaped things that
stick out on the side of the fuselage. I wouldn't want
one of those on my
glider.
I'm sure you guys are talking about a much simpler
arrangement. I'm
also sure that they are much more accurate than the
ones I'm familiar
with. That being said, this is where I stick my foot
in my mouth, IAS and
AoA probably would be much more help in a thermal than
landing. I think
Jim Pane once taped a piece of yarn to the side of
his canopy for
thermaling. You might check with him. If you are doing
spot landings the
IAS is not accurate enough. (I used to actually stall
on downwind, just to
check out where the needle pointed. gives you a very
accurate reference
point. And if just shooting a landing a 1.3 VS would
give you plenty of
margin. How much are we going to spend for this AoA?
And why is
everyone so worried about stalling on final. If you
are low and slow think
about putting it down long before you get to final.
I can almost guarantee
that in that situation you will be glued to the airspeed.

Two cents worth
Chuck

Marc Ramsey wrote:
toad wrote:
On Dec 19, 3:43 pm, John Smith wrote:
...snip...
for me. I don't see what an AoA instrument could add to this. If you are
distracted enough to get slow with an ASI, then I see no reason why you
wouldn't be distracted enough to get slow with an AoAI.

This seems to be the real reason people stall. It's not that they
don't know what the speed is, it's that they can't maintain the speed
that they do know !

An indicator for an AoA meter could consist of something as simple as
three LEDs, say a bright red one for approaching stall, green for
minimum sink, blue for best L/D and above, with the red LED blinking
faster as AoA gets closer to stall.

You could do all that with a single, tri-colour LED, though the colors
would be red/yellow/green. The single LED may well be easier to mount
and I doubt you'd miss any information by having all the colors at the
same point - nobody has (yet) suggested any form of bar-graph display.

--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Ian wrote:


I generally find that my attention is fully occupied while landing.

When isn't it? I always find myself falling behind somehow whenever I
begin to merely enjoy the scenery.


If I had an AoA indicator, I would have to take attention away from
something else to look at it...

There is a thing we in the game call a cross-check: look into it.


(I always have the audio vario and radio
off for the final approach).

Now I get it, Ian: you are really a troll/FAA Inspector, here to roil
the waters on r.a.s. We can play that game.

The vario-off mode is OK, if you must reduce the aural clutter, but
please tell us how you believe that turning off a major link (radio) you
have with one of the greatest hazards in flying (other traffic) is going
to improve your longevity: and in the pattern, no less? Horrified minds
want to know.


Would an AoA...indicator free up some
of my attention, and if so, from what?

An AoAi would give you a reliable indication of the actual and, in
concert with other instruments (ASi, RoC/Vario) and the seat of your
pants, the potential performance of your wing. There is no single item
that I know of which will virtually fly the aircraft for you: certainly
the AoA will not.

What is it which you would like to be able to do, or to know--and in
what phase of flight?



Jack

John Smith wrote:


The solution is simple: Just don't get slow on your turn to final.

Thank you, John. Go to the head of the class.

Now, what is "slow"?



Jack

toad wrote:

On Dec 19, 3:43 pm, John Smith wrote:

I don't see what an AoA instrument could add to this. If you are
distracted enough to get slow with an ASI, then I see no reason why you
wouldn't be distracted enough to get slow with an AoAI.

This seems to be the real reason people stall. It's not that they
don't know what the speed is, it's that they can't maintain the speed
that they do know !

Again, the nail has been struck directly on its head!

The truth is: they can, but they do not. What prevents them from doing
so? What should they do that they do not do?


Jack

Ian wrote:


Now, if all gliders had AoA gauges, you could jump from one glider to
another and not worry about what the right approach speed is for the
glider you happen to be in.

Wouldn't I have to worry about what the right approach AoA was
instead?

The stalling angle of attack for a given class of airfoils is very
nearly the same for each. In any case, the indicator could be marked
appropriately, or in some way provide you with that information just as
our present ASi's have green arcs, white arcs, yellow radials, red
radials, and AS bugs, etc. Marc's comment concerning LED's is another
alternative.


Jack

"Martin Gregorie" wrote in message
...
Marc Ramsey wrote:
toad wrote:
On Dec 19, 3:43 pm, John Smith wrote:
...snip...
for me. I don't see what an AoA instrument could add to this. If you
are
distracted enough to get slow with an ASI, then I see no reason why you
wouldn't be distracted enough to get slow with an AoAI.

This seems to be the real reason people stall. It's not that they
don't know what the speed is, it's that they can't maintain the speed
that they do know !

An indicator for an AoA meter could consist of something as simple as
three LEDs, say a bright red one for approaching stall, green for minimum
sink, blue for best L/D and above, with the red LED blinking faster as
AoA gets closer to stall.

You could do all that with a single, tri-colour LED, though the colors
would be red/yellow/green. The single LED may well be easier to mount and
I doubt you'd miss any information by having all the colors at the same
point - nobody has (yet) suggested any form of bar-graph display.

--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

20% of males suffer some degree of color blindness. A multi-color LED would
be difficult for them to interpret.

In any event, a 3-color LED is just 3 different LED's in the same case so
stacking 3 LED's in a vertical column is neither more nor less complicated.