Aoa

[Av8r3400]

A wing can stall at any speed but has only one critical angle of attack.

[av8rps]

Yeah, I agree. But when you calibrate it you are primarily identifying at what speed and angle the wing begins losing lift, right? Again, maybe I'm still missing something? But with such a docile airfoil as the Kitfox has that gives you a shaking and shuddering prior to stalling, isn't that much like having an AOA alarm going off, telling you the wing is about done flying?

For the record, I would see an AOA as a huge benefit to a fast aircraft like a Glasair 3, a F-18, with a stall that is abrupt. Without one it's likely the average pilot is going to fly it at the lower speed of the envelope much faster than is really needed, in fear of a stall close to the ground.*

But heck, I've been flying like that for the last 40+ years. As I tell my friends, unless I need to get into a super tight strip, "I give it an extra 5 or 10 mph for Mom as she appreciates that"

But to go into a super short strip I fly just above the stall (onset of airframe buffeting) and carry power to control descent. And of course that airframe buffeting happens at a different speed when heavy verses light, etc. So you have to learn your airplane well, as those numbers change based on a bunch of variables.

Would that be different if I had an AOA? Again, I'm just curious to learn what I might not understand...

[av8rps]

Yeah, I agree. But when you calibrate it you are primarily identifying at what speed and angle the wing begins losing lift, right? Again, maybe I'm still missing something? But with such a docile airfoil as the Kitfox has that gives you a shaking and shuddering prior to stalling, isn't that much like having an AOA alarm going off, telling you the wing is about done flying?

For the record, I would see an AOA as a huge benefit to a fast aircraft with a stall that is abrupt. Without an AOA in those aircraft it's likely the average pilot is going to fly it at the lower speed of the envelope much faster than is really needed, in fear of a stall close to the ground.* But heck, I've been flying like that for the last 40+ years. As I tell my friends, unless I need to get into a super tight strip, "I give it an extra 5 or 10 mph for Mom as she really appreciates that"

But to go into a super short strip I fly just above the stall (near onset of airframe buffeting) and carry power to control descent. And of course that airframe buffeting happens at a different speed when heavy verses light, etc. So you have to learn your airplane well, as those numbers change based on a bunch of variables.

Would that be different if I had an AOA? Again, I'm just curious to learn what I might not understand...

[n85ae]

Exactly what av8rps says here.

Yeah, I agree. But when you calibrate it you are primarily identifying at what speed and angle the wing begins losing lift, right?...

[jiott]

There are many places on the internet where you can read really good explanations of AOA and measuring systems. In a nutshell what I have gathered is that stall has very little to do with airspeed but everything to do with wing chord angle to the relative wind direction. If all conditions remain the same as is true in many landing approaches, then yes airspeed can be a good indicator. But if things change such as bank angle, flap configuration, control coordination, and some other things I can't remember now, then airspeed is no longer an accurate measure; however AOA instrumentation is still accurate. You and only one other guy I know has the balls to actually fly a short field approach with the wing starting to shudder. Since all AOA instrumentation is progressive rather than singular, you can fly a short field approach as close to or as far away from stall as you feel comfortable. I like my Dynon system that starts a slow beep in my headphones and progressively gets faster until the beep becomes a steady tone immediately before stall buffet. This progression is programmable during the setup and calibration. It also allows you to keep your eyes outside where they belong.

[Floog]

AOA in a KF is a waste of $$.

[Esser]

I like the idea of an audible alert so your eyes are outside.

[Floog]

Good point. I just rely on seat of the pants and sink rate. Below 45-50 mph sink rate increases proportionally. When you're falling like a rock, you're probably stalled....

[Av8r3400]

I like the idea of an audible alert so your eyes are outside.

I do too. Having the Dynon in the panel, it wasn't a big leap to get e dual pitot tube and hook it up.

Many people don't understand this isn't just a speed warning, it is a differential pressure measurement by two differently angled pitot tubes giving the angle of the relative wind to the wing chord.

[aviator79]

There are many places on the internet where you can read really good explanations of AOA and measuring systems. In a nutshell what I have gathered is that stall has very little to do with airspeed but everything to do with wing chord angle to the relative wind direction...

This.
To placard your panel in lieu of an AOA indicator, you'd have to have a multi-dimensional lookup table with at least bank angle, weight, CG location, and you'd have to cross-reference several instruments with that table to know at what speed your plane will stall. A common stall/spin LOC scenario is pulling too hard of a bank to compensate for overshooting final. I very much doubt you'll take the time to figure out your stall speed in that scenario, but an AOA indicator can let you know how much margin you have at a glance.

You may or may not find that AOA information is necessary or useful the way you fly your airplane, but making a table is definitely not the same thing as having a calibrated AOA indicator.