In my case I learned to fly the backcountry on my own, no backcountry instructors in Costa Rica.
So bought an AoA indicator when I had about 100 hrs total time, and learned to trust it and get the most out of it.
Yes seats of the pants is there but the HUD just confirms what I am feeling from the airplane, and stall warning can be going off, but the HUD its showing you exactly the amount of lift you got.
2,000hrs later bought a second airplane a CJ6 Nanchang, the day I bought the plane, I ordered an AoA indicator.
They do work and are a great addition IMHO and does not makes you any less of a pilot to accept it.

Thanks for the focus on AOA. I like the HUD type. I expect it’s more useable than the panal mounted displays.

Pinecone wrote:Thanks for the focus on AOA. I like the HUD type. I expect it’s more useable than the panal mounted displays.

That is the idea , so you are looking outside.
I see new ones in digital displays in the panel, not very visible, which misses the point a bit.

Slowing on short final, below 1.3 Vso, using increased AOA by HUD or to preventing increase in apparent rate of closure, allows touchdown slowly and softly on the beginning of the landing zone.

Larry,

Per our phone conversation, I'm pretty keen on adding an AoA system to my plane.

I went to the Alpha Systems website (http://alphasystemsaoa.com) to try and better understand the product. What is going on with the HUD on the video on their front page of the plane landing in a crosswind? It goes from one bar to full bars and back to one. It turns on and off. I wouldn't want that type of visual distraction on short final. As marketing videos go, it is one of the worst I've seen.

When I watch your video the progression of lights is much more helpful and the ability to see out the windscreen helps picture when and how the tool is useful.

I think you could put together a much better video for them.

Allan

albravo wrote:Larry,

Per our phone conversation, I'm pretty keen on adding an AoA system to my plane.

I went to the Alpha Systems website (http://alphasystemsaoa.com) to try and better understand the product. What is going on with the HUD on the video on their front page of the plane landing in a crosswind? It goes from one bar to full bars and back to one. It turns on and off. I wouldn't want that type of visual distraction on short final. As marketing videos go, it is one of the worst I've seen.

When I watch your video the progression of lights is much more helpful and the ability to see out the windscreen helps picture when and how the tool is useful.

I think you could put together a much better video for them.

Allan

I haven't looked at the Alpha Systems videos lately, but just as a comment (since I have an Alpha Systems AOA indicator in my airplane), there will be a fluctuation caused by any kind of turbulence. In my system, which is pretty basic and uses an analog display, the needle bounces quite a bit in turbulence. I don't think that's avoidable. The reason for the bouncing is that the angle of attack is changing constantly in turbulence. If it were to be dampened in some fashion, I think it would diminish the usefulness of the AOA indicator.

As for HUD, however it's installed, having it on top of the panel where it is within the pilot's peripheral vision is imperative, IMHO. It isn't much good, buried down on the panel or melded into an MFD as just one of many thingies. It becomes the single most important instrument on short final with the airplane at its ideal angle of attack for that weight and airspeed.

After flying with mine for well over 500 hours now, I still find myself confirming what it is telling me by glancing at the airspeed indicator. Especially when I'm flying light, with less than half tanks and nobody else aboard, sometimes I'm actually surprised at how slow I'm flying, although the AOA needle is still within the middle of the yellow band. A week ago, for instance, I glanced down at the ASI and saw 55 mph--pretty poky. But I had minimal fuel aboard, no pax, not a lot of extra stuff, just me--and hey, I've lost weight, too! (not enough) And the airplane was solid as a rock.

At my age, I'll never own another airplane, but if I did, the first improvement would be an AOA indicator. My only complaints about mine are that it's hard to see at night (an indicator using lights instead of a needle would be better), and it doesn't adjust for flap deployment. But otherwise, it's a solid, welcome improvement that I think every airplane should have installed.

Cary

Cary wrote:…...sometimes I'm actually surprised at how slow I'm flying, although the AOA needle is still within the middle of the yellow band. A week ago, for instance, I glanced down at the ASI and saw 55 mph--pretty poky. But I had minimal fuel aboard, no pax, not a lot of extra stuff, just me--and hey, I've lost weight, too! (not enough) And the airplane was solid as a rock....

Motoadve, ypou posted on another website that you calibrated your AOA device at 1.3 x Vso.
That seems kinda fast for STOL ops.
How does your calibrating speed play out on the display--
does the "sweet spot" (middle of yellow band per Cary's post, above) indicate that 1.3 Vso airspeed,
and the bottom of the yellow band indicate a stall?

Watching a couple of your videos, it looks like Jon approaches at a slower speed in his C170--
does he also have an AOA indicator?

Yes, motoadve, what Hotrod180 is after would be useful information. It is interesting that apparent rate of closure works equally well for the camera on the ground as for the pilots vision outside the cockpit. The camera captures both you and the 170 go below 1.3 Vso on short final. I know that because your rate of closure does not appear to speed up. If either you, or the 170, remained stabilized at 1.3, or any stabilized airspeed, the ground camera would show an apparent increase in rate of closure as you came close. The camera in the airplane, and the pilot, see the same brisk walk apparent rate of closure all the way down as well.

You mentioned that the AOA heads up display helped you, without instruction, develop better feel for kinetics, buoyancy, and such. I very much agree, and furthermore, feel that most instruction would have mitigated that important feel to comply with V speed implications.

While promoting the heads up AOA display, I feel you could advance aviation safety even more by pointing out the interrelation with kinetics, buoyancy, reduction in relative wind noise, change in sight picture over the nose, and that the airplane does not appear to speed up.

Your AOA indication is real and the apparent brisk walk rate of closure I am talking about is just that: APPARENT. Both are extremely important in short field work.

Seems useful, but what's the point of correlating it with reference airspeeds? Isn't the point to get away from the concept of airspeed? Or is Vy (for instance) just a known benchmark?

I imagine that guidance comes from the mfr. Why wouldn't they do a calibration starting with full break, then moving gradually lower AoA for safer reference angles?

hotrod180 wrote:

Cary wrote:…...sometimes I'm actually surprised at how slow I'm flying, although the AOA needle is still within the middle of the yellow band. A week ago, for instance, I glanced down at the ASI and saw 55 mph--pretty poky. But I had minimal fuel aboard, no pax, not a lot of extra stuff, just me--and hey, I've lost weight, too! (not enough) And the airplane was solid as a rock....

Motoadve, ypou posted on another website that you calibrated your AOA device at 1.3 x Vso.
That seems kinda fast for STOL ops.
How does your calibrating speed play out on the display--
does the "sweet spot" (middle of yellow band per Cary's post, above) indicate that 1.3 Vso airspeed,
and the bottom of the yellow band indicate a stall?

Watching a couple of your videos, it looks like Jon approaches at a slower speed in his C170--
does he also have an AOA indicator?

Just adding a little. When I calibrated mine, per the instructions that came with it, I flew at the slowest level speed possible while still being able to maintain full control, without any flaps. That is the "alpha angle", and the needle on mine is supposed to rest on the line between red and yellow at that point. Mine took quite a bit of adjusting to get it to that point. The stall occurs a few needle widths into the red zone. With flaps, since the instrument doesn't compensate for flap deployment, the needle will go well into the red, almost to the bottom of the red, before a stall. So there's lots of margin for safety, calibrating it for no flaps and then landing with flaps.

That landing a week ago was with 20 flaps. There was a moderately gusty crosswind, maybe 10G14 about 30 degrees off the nose--enough that I don't like to use full flaps, but not so much that it should be no flaps. It still took a lot of rudder.

Cary

I think what Zane and 180 are getting at is that an AoA device shouldn't include lots of margin for safety because standard training and the POH provide that. I want to know when I'm going to fall out of the sky.

Back when they were pretty new I had a car with the proximity sensors in the bumper. They would beep as you got close to an object, then to solid when you were 'real close'. Problem was, it went to a solid tone at about 18 inches which really wasn't much of a help for close quarters navigation. I can estimate 18", I want something that goes to a solid tone at about 3".

If I understand the AoA device, it all depends how you calibrate it. I'm pretty sure you can calibrate it to go red when there is no lift remaining.

They also have compensation for flap settings now.

albravo wrote:I think what Zane and 180 are getting at is that an AoA device shouldn't include lots of margin for safety because standard training and the POH provide that. I want to know when I'm going to fall out of the sky.

That wasn't really my point, but close. My point was that airspeed has always been used because it's (somewhat) easy to measure and...it's just always been a staple paradigm of aerodynamics because of the fluid physics. But if what we seek from flying by AoA is really "lift reserve" then why bother correlating with Vy, et al?

albravo wrote:I think what Zane and 180 are getting at is that an AoA device shouldn't include lots of margin for safety because standard training and the POH provide that. I want to know when I'm going to fall out of the sky.

Back when they were pretty new I had a car with the proximity sensors in the bumper. They would beep as you got close to an object, then to solid when you were 'real close'. Problem was, it went to a solid tone at about 18 inches which really wasn't much of a help for close quarters navigation. I can estimate 18", I want something that goes to a solid tone at about 3".

If I understand the AoA device, it all depends how you calibrate it. I'm pretty sure you can calibrate it to go red when there is no lift remaining.

They also have compensation for flap settings now.

I agree to a point. From my experience, you do need some margin because in even mildly bumpy air you’ll see some decent excursions from the blue dot even if you’re holding steady.

Zzz wrote:

albravo wrote:I think what Zane and 180 are getting at is that an AoA device shouldn't include lots of margin for safety because standard training and the POH provide that. I want to know when I'm going to fall out of the sky.

That wasn't really my point, but close. My point was that airspeed has always been used because it's (somewhat) easy to measure and...it's just always been a staple paradigm of aerodynamics because of the fluid physics. But if what we seek from flying by AoA is really "lift reserve" then why bother correlating with Vy, et al?

My opinions here:

AoA being labeled as “lift reserve” is somewhat misleading.

The terms Vx and Vy can still be used since they’ve permeated aviation. Or you could use the terms best climb angle and best climb rate if you prefer, but that’s more syllables and not likely to catch on. Either way, you’re flying a wing angle centered around two different efficiencies.

Airspeed has always been used because it’s always been used. It was easy from the beginning to measure using a flat plate, a spring, and a dial indicator. But airspeed is an approximation of wing angle that requires adjusting based on loading and atmospheric conditions. Much better to just measure the value that matters. “Airspeed” as it pertains to fluid dynamics is in itself a ton of variables that are no fun to play with. Better to just measure the angles.

CamTom12 wrote:My opinions here:

AoA being labeled as “lift reserve” is somewhat misleading.

The terms Vx and Vy can still be used since they’ve permeated aviation. Or you could use the terms best climb angle and best climb rate if you prefer, but that’s more syllables and not likely to catch on. Either way, you’re flying a wing angle centered around two different efficiencies.

Airspeed has always been used because it’s always been used. It was easy from the beginning to measure using a flat plate, a spring, and a dial indicator. But airspeed is an approximation of wing angle that requires adjusting based on loading and atmospheric conditions. Much better to just measure the value that matters. “Airspeed” as it pertains to fluid dynamics is in itself a ton of variables that are no fun to play with. Better to just measure the angles.

I disagree with your opinions, my much more experienced air-beating-into-submission friend. Angle or speed? I realize they're inseparable because...air, but if airspeed is an approximation of angle, and we now have the means to reliably measure angle, why not commit?

I feel like at this point AoA is still an augmentation of instrumentation, apologetically trying to get into the cockpit against the suspicious stink-eye of 100+ years of aviation convention. Instead, it should be front and center, and the airspeed stuff tossed out, at least for low speed work. IMO clinging to the old to help smooth the transition in paradigm is making it harder.

Caveat: I'm not an AoA evangelist, far from it. I've only flown with an AoA once and I couldn't get into it because my old friend the steam airspeed indicator was right there. I most often just fly with my butt gauge, which is why I'm so good at talking out my ass (like now.) I have wondered what it would be like to cover the ASI and try flying by AoA alone.

Zzz wrote:

CamTom12 wrote:My opinions here:

AoA being labeled as “lift reserve” is somewhat misleading.

The terms Vx and Vy can still be used since they’ve permeated aviation. Or you could use the terms best climb angle and best climb rate if you prefer, but that’s more syllables and not likely to catch on. Either way, you’re flying a wing angle centered around two different efficiencies.

Airspeed has always been used because it’s always been used. It was easy from the beginning to measure using a flat plate, a spring, and a dial indicator. But airspeed is an approximation of wing angle that requires adjusting based on loading and atmospheric conditions. Much better to just measure the value that matters. “Airspeed” as it pertains to fluid dynamics is in itself a ton of variables that are no fun to play with. Better to just measure the angles.

I disagree with your opinions, my much more experienced air-beating-into-submission friend. Angle or speed? I realize they're inseparable because...air, but if airspeed is an approximation of angle, and we now have the means to reliably measure angle, why not commit?

I feel like at this point AoA is still an augmentation of instrumentation, apologetically trying to get into the cockpit against the suspicious stink-eye of 100+ years of aviation convention. Instead, it should be front and center, and the airspeed stuff tossed out, at least for low speed work. IMO clinging to the old to help smooth the transition in paradigm is making it harder.

Caveat: I'm not an AoA evangelist, far from it. I've only flown with an AoA once and I couldn't get into it because my old friend the steam airspeed indicator was right there. I most often just fly with my butt gauge, which is why I'm so good at talking out my ass (like now.) I have wondered what it would be like to cover the ASI and try flying by AoA alone.

I respect your opinion, but here’s some quick counters:

- it’s hard to translate wing angle into time enroute to destination, but airspeed is only a small amount of math away. It doesn’t make sense to measure the angle when it’s meaningless to that phase of flight. I’d argue the same could be said for measuring airspeed, when all you really want to know is how far you are from the critical angle of attack...

- if AoA was merely a gadget, why would the Navy have been using it for decades? They like to take the term “short field landing” to the extreme.

- I agree with you on actually using AoA. Primacy is a real thing, and it’s hard to get past. One of the fixed wing aircraft I’m qualified in requires an AoA approach as part of the annual check ride. Unless you practice it, you’ll never be comfortable with it. Just like spot landings and dynamic, proactive rudder.

CamTom12 wrote:It doesn’t make sense to measure the angle when it’s meaningless to that phase of flight.

i think somewhere up there I did qualify for low-speed work.

CamTom12 wrote:- if AoA was merely a gadget, why would the Navy have been using it for decades? They like to take the term “short field landing” to the extreme.

I should have clarified, I mean the resistance to change is present in general aviation.

Having not used the airspeed indicator on short final to touchdown for fifty years, I have to agree with Zane that the heads up AOA display will increase safety and efficiency should progress become sanctioned. I hope an equally beneficial outcome will be better kinetic, aural, seat of pants (Zane's butt gauge), development.

Both of you are young. Airspeed has not always been used. It was kinetic and aural. Aural pitch of wire braces were very helpful in the Stearman, but relative wind noise in any. That good training was suppressed in favor of integration of instrument with contact situational awareness after WWII and finally predominantly basic instruments flying.

Zzz wrote:

CamTom12 wrote:It doesn’t make sense to measure the angle when it’s meaningless to that phase of flight.

i think somewhere up there I did qualify for low-speed work.

No, you did. I missed that on my first read through, my apologies.

Zzz wrote:

CamTom12 wrote:- if AoA was merely a gadget, why would the Navy have been using it for decades? They like to take the term “short field landing” to the extreme.

I should have clarified, I mean the resistance to change is present in general aviation.

That’s what I thought you meant. The point wasn’t meant for you personally but meant to add to my comment about primacy. I could have worded that better myself!

The Wright brothers only had one instrument on the original Wright Flyer... What was it??

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