AOPA Live! on Angle of Attack

[@speedomars]

Once again we have a misunderstanding of the AoA meter and how to best use it. The AoA meter is NOT a replacement for indicated airspeed in the pattern and on approach to land. The tool can be used to AUGMENT by visually verifying the angle of the wing in turns close to the ground. If your airspeed is under control you should still not have trouble making these turns with too much or too little energy possibly leading to excess load factors or pulling up on the nose to maintain altitude and exceeding the critical angle of attack. It is a BACKUP to the basic and proven techniques to fly a given indicated airspeed in the pattern and over the numbers when landing. One other point that is often misunderstood. The Vs0 is the same number regardless of density altitude. The only adjustment should be for gust factor.

[@artistwithcameras]

That is actually incorrect. Lift is a function of air density, velocity squared, the wing area and the Coefficient of lift. L=1/2pV^2SCl Vso changes with WEIGHT, BANK ANGLE, LOAD FACTOR. It is a basic principle and is used in Introduction to Naval Aviators and why US Navy solely uses AoA to land on carriers. At high density altitudes, say Telluride as an example, you need a higher AoA given the drop in air density. Thus you can control that with Airspeed, pitch or wing area. As to the "backup" notion. Well, if you read page 75-78 of Stick and Rudder he would disagree. We are slowly evolving to a world where the technology will be cheap enough that AoA will eventually be the primary tool for landings and slow/low flight.

[@speedomars]

@@artistwithcameras The aerodynamic definition of lift is not in the argument. And, btw, even during stall the wing is still producing lift, just not enough to keep the aircraft aloft. You do not change IAS speeds dependent on density altitude. The only time you add speed to Vs0 is for a gust factor which can increase drag when landing. At typical civilian aircraft operating speeds, the aircraft's aerodynamic structure responds to dynamic pressure alone (difference between total pressure and static pressure), and the aircraft will perform the same when at the same dynamic pressure. Thus, one should NOT deviate from the V speeds published in the POH. An AoA meter is useful to verify visually when low and slow during take-off or from base to final that wing angle is not near critical. But it is a FYI only and should not supplant or take the place of maintain the IAS speeds as documented in the aircraft POH.

[@artistwithcameras]

@@speedomars that will change in time. The FAA is making a case for it in the future. I’ve already been in touch with them on it.

[@edcew8236]

AOA visual displays? Well, no... there are fundamental issues that this video ignored. * Three research papers show that loss of control has unusual attitudes as a factor comparable to AOA. My own research indicates that stall/spin is over-reported as an accident mechanism, and this finding found agreement with an aerospace professor and the head of safety for a major aerospace corporation. In other words, if you count on AOA to prevent loss of control, it will be ineffective for a significant number of events. * AOA has very strange lead/lag characteristics when maneuvering. In other words, you can only really use AOA when everything is calm. That’s what they did in this video, fly smoothly with no quick maneuvering. * AOA is very noisy, especially in turbulence. One way to hide this failing is to make the resolution so coarse that the noise is hidden which, by the way, means that the guidance becomes low precision. They did that in this video, too. Actually, it looks like they were flying pitch attitude (good practice) to find a good AOA in smooth air. * So how do you make a visual that makes AOA look good? Smooth air, smooth maneuvering. Nobody makes AOA videos in up and downdrafts because it would show up the problems with AOA. * Saying that AOA is lift and airspeed is energy is flat out wrong. The lift equation shows that lift depends on BOTH airspeed and AOA. The AOA narrator ought to know that. His platitude does aviation a disservice. * Aural stall warning, yes. Visual AOA? A fad that refuses to go away. One vendor wrote, “I discontinued my AOA glareshield display product 10 years ago because it did not solve the problem.” BTW, I gave a forum at Oshkosh two years back talking about the failings of AOA, and those failings are fundamental, not vendor-specific.

[@artistwithcameras]

Incorrect. Not true. I fly in turbulence and gusty 30 knot winds all the time. It’s instant at letting me know wind shear is about to hit. Why? Because it measures changes in relative wind. You can see turbulence affect the indicator as well. I have no idea about your experience or education. But I can tell you this is. It the case. Come fly with me and I will Show you.