Flying by AoA
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Unit74
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Unit74
Very unusual terrain for Hawaii...
motoadve
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motoadve
455 Bravo Uniform
Final Approach
Yep, I like the larger number of segments in that display the best out of all the options, because it seems more fine and precise. It’s on my wish list, just cuz.
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Velocity173
My question has always been, what’s the difference in kts in flying book approach speed (1.3 Vso) vs flying the “blue donut”? If it’s not more than 5 kts, it’s not important in 99% of the flying that we do in GA.
This reference to military flying is always brought up. There’s no correlation between GA and military. A guy landing on board a ship or max performing his aircraft to the limits, needs an AoA. A typical GA pilot landing on a 5,000 ft paved runway, doesn’t need an AoA.
A stall horn or light will provide the same warning but just in a more simplified manner. If you’ve truly panicked and are about to suffer a low altitude spin accident, no AoA is going to wake you up in time to prevent a crash. It’s nothing more than an upgraded stall warning device. Something that I don’t have on neither one of my planes and somehow I’m still alive to talk about it.
This reference to military flying is always brought up. There’s no correlation between GA and military. A guy landing on board a ship or max performing his aircraft to the limits, needs an AoA. A typical GA pilot landing on a 5,000 ft paved runway, doesn’t need an AoA.
A stall horn or light will provide the same warning but just in a more simplified manner. If you’ve truly panicked and are about to suffer a low altitude spin accident, no AoA is going to wake you up in time to prevent a crash. It’s nothing more than an upgraded stall warning device. Something that I don’t have on neither one of my planes and somehow I’m still alive to talk about it.
Kenny Phillips
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AoA is not a warning device. It's a flight instrument. But I could fly, in decent weather, with no panel at all (and have done so.) I'd still like an AoA, where you can see where you airplane is trending in the flight envelope.
James331
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James331
And here I was thinking a plane owned by the goverment flys by the same physics as a plane owned by a citizen.
FlySince9
En-Route
Can someone ( or everyone) explain to me how an AOA is any better than a simple stall horn? It escapes me how this thing is installed to be such a miracle for stall avoidance because each wing can have a different AOA depending on current flight conditions... what’s to say while in a step turn trying to return to a runway one wing won’t be beyond critical angle while the other is not? Or am I missing something?
Hacker
Pre-takeoff checklist
Your incorrect assumption is that an AOA gauge is only a tool for stall prevention.
A stall horn is a binary indicator of a single point on the wide range of AOA.
An AOA gauge is an instrument that can also tell you the best conditions for max range, max endurance, best acceleration, etc, in addition to giving you a more gradient look at the lift performance of the wing throughout the envelope.
Use of airspeed for any of those conditions are only approximate analogs (with certain weight, CG, and other assumptions) while the AOA is the actual determining performance factor.
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How many citizens are flying a private F-18 and are operating to the limits of the airframe? That’s the type of flying where an AoA gives enough SA to matter.
One shouldn’t be violently yanking and backing their C-172 in a traffic pattern. If they are then they should know the limits of their aircraft before a spin occurs. If they’re too inexperienced to know the limits of their aircraft then no stall warning, or AoA device will matter. They’ll go from a blue doughnut to a red chevron in the blink of an eye and will be too preoccupied with outside distractions. SR22 accident in Houston comes to mind.
Hacker
Pre-takeoff checklist
Again, it has a lot more uses than simply stall awareness.
That being said, it is a substantially better stall awareness tool than a horn, and is especially useful when you do need to "max perform" the wing (terrain avoidance, unusual attitude recovery, etc).
FlySince9
En-Route
I’m not sure you answered my question
James331
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I’d say number for number, probably more private planes per day are pushed toward the edge than mil planes.
There’s more to GA than flying book speeds in a 172 into a huge runway ya know
Hacker
Pre-takeoff checklist
You asked why it was better than a "simple stall horn", and I gave you several reasons.
The most significant one is that a horn is a single snapshot of wing lift generation, while an AOA gauge shows the entire performance envelope of the wing.
Additional reasons include the other data about range and endurance it can provide.
FlySince9
En-Route
But i
But if each wing can have a different AOA, depending on flight conditions, how are you getting a true snapshot of what’s going on? You can still have one wing generating lift while the other is past CAOA...
But if each wing can have a different AOA, depending on flight conditions, how are you getting a true snapshot of what’s going on? You can still have one wing generating lift while the other is past CAOA...
Hacker
Pre-takeoff checklist
If there are momentary differences when right near the critical AOA, then you will get wing rock. The same situation as if you've ever done a "falling leaf" or "full aft stick stall". One will fall and the other one won't. And, as you know if you've done those things, you can still control the airplane through that wing rock, AND you know when you've released enough back pressure to get back below critical AOA.
No, it isn't a magic way of knowing the specific AOA at every slice of the wing across the entire wingspan, but it provides substantially more information about wing performance than the stall horn.
Hacker
Pre-takeoff checklist
Here's the T-38C AOA gauge. Notice that the max range, max endurance, and optimal turn performance AOAs are marked. Also note that it shows there the buffett starts, where the actual stall AOA is, and continues to indicate post-stall (out to 1.1 AOA, but in practice it goes out to about 1.2 AOA post-stall).
A stall horn is analogous to a blank gauge with one single line at 0.9 AOA.
A stall horn is analogous to a blank gauge with one single line at 0.9 AOA.
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Velocity173
But for GA, the prevention of a loss of control accident is based on stall awareness and that’s what these are being sold as. That and the fact they’re being touted as a better tool for a stabilized approach. This has shown through a recent study to be of no statistical significance.
https://aviation.osu.edu/sites/aviation.osu.edu/files/uploads/aoa_summary_1_22_2016.docx
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Velocity173
Sure but they represent a small slice of GA. Also, how many of those examples are using or even in need of an AoA device? Is it going to benefit an aerobatic performer at the altitudes that they preform at? Probably not.
This is about understanding aerodynamics and knowing the limits of your aircraft. Don’t need a AoA device in order to do it safely. Basic airmanship is missing today in pilot training. Pilots don’t understand AoA and it’s relationship with AoB. A lot of pilots would be better served attending an unusual attitude course vs installing an AoA.
Hacker
Pre-takeoff checklist
Just because a study days they don't have statistical utility for that particular instance which AOA indicators are being marketed for, it doesn't in any way invalidate the other utilities.
There's a substantial difference between discussing a specific product which has a specific display of specific things being measured and a concept that can be adapted to show just about anything someone finds does have utility.
Hacker
Pre-takeoff checklist
This isn't a discussion of need, it is a discussion of what could be performing a current task better.
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Velocity173
I believe they have utility for what you do. I imagine, you could save a significant amount of fuel in an F-15 by flying a wing profile vs a speed or power setting. For me, in my little single engine GA, the fuel savings of an AoA profile vs book power settings, won’t be of significance. I’d love to see the numbers of such a test for small SE GA but I haven’t seen any.
The fundamental thing in flying is “a man gots to know his limitations” as Harry once (or several times) said. If an AOA helps with that get one and use it. If it doesn’t, don’t waste the money.
I found in an F-14 it certainly helped in many situations. OTOH, in a Technam P92, less that useful. Learn what it can do and make your own choice. I plan to have one in my Onex but certainly not in the Aerolite 103.
YMMV
Cheers
I found in an F-14 it certainly helped in many situations. OTOH, in a Technam P92, less that useful. Learn what it can do and make your own choice. I plan to have one in my Onex but certainly not in the Aerolite 103.
YMMV
Cheers
motoadve
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motoadve
Here are some examples.
There was a discussion in go around in a loaded 182 with full flaps, some pilots with thousands of hours said go around with partial power instead of full power, so the pitch up is not as extreme, but what speed and how much power to add?
If you have an AoA indicator you dont have to guess.
Short gravel bar approach, stall warning going off, you want to land at minimum speed, you hear the stall warning but see how much lift you got thru the AoA indicator, telling exactly the amount of lift you got.
Engine quits at cruise, fly the best glide by AoA, getting the most performance of your glide.(not guessing the speed calculating the weight of the plane , temp etc)
Take off , save time and fuel flying by Vy with the AoA
Short runway, trees on the other end, get the perfect Vx with the AoA
Overshoot in the pattern (everyone can make a mistake) correct and check your AoA and will tell you whats going on before the stall warning goes off.
You dont need it, but having it adds safety and does not make you any less of a proficient pilot.
I bought mine almost 2,000hrs ago, wanted to learn to fly the backcountry in Costa Rica and there was no instructor for that, my AoA indicator was the best investment.
Bought a new plane , the CJ6 Nanchang, first mod I added was an AoA indicator.
Once you get used to one, there is no turning back.
There was a discussion in go around in a loaded 182 with full flaps, some pilots with thousands of hours said go around with partial power instead of full power, so the pitch up is not as extreme, but what speed and how much power to add?
If you have an AoA indicator you dont have to guess.
Short gravel bar approach, stall warning going off, you want to land at minimum speed, you hear the stall warning but see how much lift you got thru the AoA indicator, telling exactly the amount of lift you got.
Engine quits at cruise, fly the best glide by AoA, getting the most performance of your glide.(not guessing the speed calculating the weight of the plane , temp etc)
Take off , save time and fuel flying by Vy with the AoA
Short runway, trees on the other end, get the perfect Vx with the AoA
Overshoot in the pattern (everyone can make a mistake) correct and check your AoA and will tell you whats going on before the stall warning goes off.
You dont need it, but having it adds safety and does not make you any less of a proficient pilot.
I bought mine almost 2,000hrs ago, wanted to learn to fly the backcountry in Costa Rica and there was no instructor for that, my AoA indicator was the best investment.
Bought a new plane , the CJ6 Nanchang, first mod I added was an AoA indicator.
Once you get used to one, there is no turning back.
455 Bravo Uniform
Final Approach
Why? The edge of the STOL envelope.
455 Bravo Uniform
Final Approach
How did you know exactly which bars were best glide? Testing in that particular plane?
How does it fail when it gets bug guts in one or both holes?
Have you seen the AeroVonics AV20 probeless AOA meter? Any opinion vs the AlphaSytems?
DaleB
Final Approach
Amen. And that's from a low time guy just out havin' fun. No sand bars, no back country strips, no low level river... well, 2 out of 3 anyway. Just having a progressive audio indication instead of a binary stall horn on short final is nice.
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Velocity173
You can fly a speed at the edge of the STOL envelope with the stall horn going off that will equate to flying in the yellow of an AoA.
Every vid I’ve seen with the aircraft flying a blue donut approach is almost exactly on the book recommended speed for the approach anyway. If there is a difference, it’s only by a couple of kts.
motoadve
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motoadve
Best glide is 4 yellow lights, after you calibrate Vso 1.3 , you automatically are calibrating Vx, Vy Vg.
I have never tried other brand , only Alpha systems, almost 2,000hrs with it, and no bugs or problems of any kind with the system.
I have never tried other brand , only Alpha systems, almost 2,000hrs with it, and no bugs or problems of any kind with the system.
455 Bravo Uniform
Final Approach
Yeah, a progressive audio signal would be nice.
My stall horn turns on at 47 indicated @ flaps 20 and 43 indicated at flaps 40. The mush-down or slight “break” happens at 35 indicated (20 & 40 flaps). A progressive audio would be great (or HUD of the AOA), just to keep my eyes ahead.
My stall horn turns on at 47 indicated @ flaps 20 and 43 indicated at flaps 40. The mush-down or slight “break” happens at 35 indicated (20 & 40 flaps). A progressive audio would be great (or HUD of the AOA), just to keep my eyes ahead.
Silvaire
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Watching John Mohr do this in a stock 3000 pound 220 hp Stearman that doesn't even have a stall horn or any of the countless performers who have done airshow performances in J3 Cubs has always impressed me far more than Tucker or Wagstaff or any of the others and I don't mean to put them down I'm just saying...
The AOA is being way over-hyped just like VG's. Yes they do what they are said to do but the notion that they are "must have" devices is not true. Basic airmanship beats all.
TRocket
Line Up and Wait
I get the point you're trying to make, but that's a pretty extreme analogy....GPS to pilotage is a little different than AoA to non-AOA...
luvflyin
Touchdown! Greaser!
Here's the T-38C AOA gauge. Notice that the max range, max endurance, and optimal turn performance AOAs are marked. Also note that it shows there the buffett starts, where the actual stall AOA is, and continues to indicate post-stall (out to 1.1 AOA, but in practice it goes out to about 1.2 AOA post-stall).
A stall horn is analogous to a blank gauge with one single line at 0.9 AOA.
What is the sensor on those? Vane? One of those Pitot kinda looking lift reserve calculator things like most of the ones made for GA planes? Or something else?
luvflyin
Touchdown! Greaser!
Have you ever compared that at different weights. Like taking off at Gross and doing it before burning up much gas. And then doing it as light as you can?
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Mantis Toboggan, MD
455 Bravo Uniform
Final Approach
No, that’s a good idea. I like going up with a pre-filled notecard “form” and doing maneuvers and filling in data. Might do that.
I was about 300 lbs under max gross, CG forwardish with fuel and 2 butts in front.