Favorite panel gadget?

Dudley Henriques wrote:
Mxsmanic wrote:
Dudley Henriques writes:

Not a moment's hesitation.......An angle of attack indicator.

I can understand that. Why are angle-of-attack indicators so rare in
aircraft? Is it something that is difficult to measure? I should
think it
would be far more useful than trying to figure out what combination of
speed,
weight, pitch angle, etc., is likely to produce a stall.

You are absolutely correct. The military for years has used AOA to
determine cruise, climb, descent, and approach speeds. Almost all high
performance aircraft performance charts use AOA to determine performance
criteria.
For example, a T38 is flown on approach at an optimum AOA of .6 units.
This optimizes the aircraft at whatever approach airspeed the GW
dictates. (remaining fuel). The aircraft can also be flown manually on
approach using an IAS of 155kts plus fuel, which is an additional 1kt
for every l00lbs remaining over 1000lbs. You can fly the approach either
way but as you can see, it's a lot easier using AOA.
Some T38's BTW, incorporate an AOA indexer on the glare shield that will
automatically keep you on speed if you fly the airplane in the on speed
green "donut". The top of the indexer is a red chevron pointing downward
to indicate you're too slow on the approach. The bottom is a red chevron
pointing upward showing too high an airspeed. Keeping the airplane right
on speed in the green donut gives you .6 units AOA regardless of the
gross weight of the airplane.
To expand just a bit on the T38, the AOA indicator shows up as arbitrary
"units" ranging from 0 to 1.0 based on the angle range of the AOA vane.
Some other helpful data supplied by the AOA indicator if I remember
right for the Talon is a maximum range at about .2 units, and a maximum
endurance at .3 units. Initial stall buffet is t about .9 units.

In light civilian airplanes, AOA indicators can be quite useful although
the low speeds involved don't necessarily produce the same advantages
found in much higher performance airplanes where the slightest
difference between optimum and off optimum AOA for a specific
configuration can mean big differences in performance.

Personally, I like the idea of basing even light airplane performance on
AOA. If this format is begun at the manufacturer's level and proper
testing on the aircraft done at that point, the end user has a simple
and precise instrument on which to base the aircraft's performance. This
decreases cockpit workload which is a good thing in itself.

It is my understanding after talking to some ATR (ATP) friends of mine
flying for major air carriers that their companies have been engaged
with manufacturers on better ways to use AOA in their aircraft operations.

Correction on the indexer. The lower chevron should read yellow and not red.

--
Dudley Henriques

Shirl wrote in news:Xmnushal8y-
:

JB wrote:
Flush toilet. I am REALLY tired of trying to stand up in a single
engine, pull my pants around my ankles, and take care of business
without totally ending up in some vertical dive-bombing death spiral.
Sticking my crank in a hole in the instrument panel would be
wonderful. Ladies...sorry, I don't know what to suggest.

I know this will sound like "mom", but ... don't have coffee before you
leave, and "go" before you saddle up?
;-)


Isn't "Pee - take" on every pilot's pre-flight check list?

On May 15, 4:16*pm, Dudley Henriques wrote:
I gave up years ago trying to figure out why things that make flying
safer and better are not made standard. :-)))
AOA indication has always as far as I know been considered an option on
light civilian aircraft. There are costs involved as well as performance
testing to determine optimum parameters....another step in the process.
The main reason I believe is the fact that light civilian airplanes fly
in the area of lowest performance where the raw data already existing
using basic instrumentation is sufficient.

They're somewhat more common on experimentals (i.e., homebuilts), and
I agree, I wish I had one on even my lowly Cherokee.

For plain vanilla flying, D, (point to point in an M20J) what
improvement might we expect using aoa instead of what we use now in
takeoff, cruise, or landing phases?

I can appreciate aoa's utility in higher performance a/c, or maybe
when flying close to some edge, but am not sure how it would improve,
for example, our take off (best rate for the first few hundred feet,
that's less than 30 seconds of flying) , then a prudent cruise climb
to our en route altitude. En route, usually as high as possible
consistent with the trip length and winds, we go to the lowest rpm we
can, and maintain the same ias going lower until approaching the OM.

Benjamin Dover wrote:
Shirl wrote in news:Xmnushal8y-
:


Isn't "Pee - take" on every pilot's pre-flight check list?

Dunno 'bout you but I tend to

"Pee- Leave"

Unless I'm in need of some ballast.

Ya know, we glider guys already have this stuff figgered out.
I learned the hard way that if the guy above you opens the gear doors while
on cruise... : )

--
Message posted via AviationKB.com
http://www.aviationkb.com/Uwe/Forums...ation/200805/1

HARRY POTTER wrote:
Mxsmanic wrote:

Dudley Henriques writes:

Not a moment's hesitation.......An angle of attack indicator.
I can understand that. Why are angle-of-attack indicators so rare in
aircraft? Is it something that is difficult to measure? I should think
it would be far more useful than trying to figure out what combination of
speed, weight, pitch angle, etc., is likely to produce a stall.

It's my understanding that AOA indicators are not on most singles because
there is no place to put it. The prop creates circling air currents all
through the fuselage, making any kind of AOA indication incorrect. You
can't put it on the wing, because whenever you banked the aircraft, the AOA
would move.

This makes me wonder, do high performance aerobatic singles, like the Extra
300 have AOA's? If so, how?



Out on the wing is where most singles have them.

http://www.aircraftspruce.com/menus/...ndicators.html


Dynon who has the indicator built into their EFIS puts the probe out on
the pitot tube.

http://dynonavionics.com/docs/D180_Feature_AOA.html

On May 16, 9:11 am, Gig 601Xl Builder
wrote:
HARRY POTTER wrote:
Mxsmanic wrote:

Dudley Henriques writes:

Not a moment's hesitation.......An angle of attack indicator.
I can understand that. Why are angle-of-attack indicators so rare in
aircraft? Is it something that is difficult to measure? I should think
it would be far more useful than trying to figure out what combination of
speed, weight, pitch angle, etc., is likely to produce a stall.

It's my understanding that AOA indicators are not on most singles because
there is no place to put it. The prop creates circling air currents all
through the fuselage, making any kind of AOA indication incorrect. You
can't put it on the wing, because whenever you banked the aircraft, the AOA
would move.

This makes me wonder, do high performance aerobatic singles, like the Extra
300 have AOA's? If so, how?

Out on the wing is where most singles have them.

http://www.aircraftspruce.com/menus/...ndicators.html

Dynon who has the indicator built into their EFIS puts the probe out on
the pitot tube.

http://dynonavionics.com/docs/D180_Feature_AOA.html

An AoA is an interesting instrument. For me (in a sim
with a customized AoA indicator), I had difficulty due to
information overload, probably because I rely on my
Attitude indicator, IAS, Rate of Descent and Altimeter,
with an ear alert for a stall buzzer.
On top of that, (in real flying), is radio, traffic, weather
such as cross-winds, flap settings, RPM, seat belt,
mooses on the runway bla-bla-bla.
All those instruments need to jive and are vital to make
a safe landing.
I've tried using modified instrument panels with some
limited success gauged subjectively, but an AoA was
a "recreational instrument", fun to watch during stalls.
Ken

Tina wrote:
For plain vanilla flying, D, (point to point in an M20J) what
improvement might we expect using aoa instead of what we use now in
takeoff, cruise, or landing phases?

I can appreciate aoa's utility in higher performance a/c, or maybe
when flying close to some edge, but am not sure how it would improve,
for example, our take off (best rate for the first few hundred feet,
that's less than 30 seconds of flying) , then a prudent cruise climb
to our en route altitude. En route, usually as high as possible
consistent with the trip length and winds, we go to the lowest rpm we
can, and maintain the same ias going lower until approaching the OM.





Generally, even in high performance airplanes, you don't reference AOA
on takeoff during rotation. If the airplane, (any airplane) has been
tested and charted for optimum climb AOA, you could set that up after
rotation for best rate for example.
The bottom line for light airplanes concerning AOA is that if it's
available, it can optimize performance for you referencing one instrument.
You can of course, as you have correctly noted, accomplish these things
manually as well.
I'm simply used to using AOA for various performance references so it's
normal for me to think in these terms.
For most pilots in light airplanes, using AOA would simply be another
option.


--
Dudley Henriques

HARRY POTTER wrote:
Mxsmanic wrote:

Dudley Henriques writes:

Not a moment's hesitation.......An angle of attack indicator.
I can understand that. Why are angle-of-attack indicators so rare in
aircraft? Is it something that is difficult to measure? I should think
it would be far more useful than trying to figure out what combination of
speed, weight, pitch angle, etc., is likely to produce a stall.

It's my understanding that AOA indicators are not on most singles because
there is no place to put it. The prop creates circling air currents all
through the fuselage, making any kind of AOA indication incorrect. You
can't put it on the wing, because whenever you banked the aircraft, the AOA
would move.

This makes me wonder, do high performance aerobatic singles, like the Extra
300 have AOA's? If so, how?


It's true the port should be placed in an area of undisturbed airflow.
This is usually out on the wing upper surface somewhere near the leading
edge but will vary from type to type. Thus placed, prop circulation
shouldn't be an issue.

Can't say I've seen an Extra with an AOA system, but there's no reason
at all the aircraft shouldn't have one if the owner so desired as far as
I can see.

--
Dudley Henriques

On May 16, 12:14 pm, Dudley Henriques wrote:
HARRY POTTER wrote:
Mxsmanic wrote:

Dudley Henriques writes:

Not a moment's hesitation.......An angle of attack indicator.
I can understand that. Why are angle-of-attack indicators so rare in
aircraft? Is it something that is difficult to measure? I should think
it would be far more useful than trying to figure out what combination of
speed, weight, pitch angle, etc., is likely to produce a stall.

It's my understanding that AOA indicators are not on most singles because
there is no place to put it. The prop creates circling air currents all
through the fuselage, making any kind of AOA indication incorrect. You
can't put it on the wing, because whenever you banked the aircraft, the AOA
would move.

This makes me wonder, do high performance aerobatic singles, like the Extra
300 have AOA's? If so, how?

It's true the port should be placed in an area of undisturbed airflow.
This is usually out on the wing upper surface somewhere near the leading
edge but will vary from type to type. Thus placed, prop circulation
shouldn't be an issue.

Can't say I've seen an Extra with an AOA system, but there's no reason
at all the aircraft shouldn't have one if the owner so desired as far as
I can see.
Dudley Henriques

What an SOB like myself would do flying a low wing
monoplane is tape fluff on the the upper surface to
observe turbulence variation over wing's lifting surface.
Maybe not the AoA you want, but it's a proportional
effect, and easy to see at a glance.

That's SOP filmed using X-craft during maneuvers.
Ken