I love your bedside manner, Cam. We old guys talk about seat of pants cues, but proprioceptive cues are whole body cues. I agree that devices can lead a pilot to good proprioceptive cues with experience, but at some point it is helpful to ditch the crutches. I think the best example of devices, and Jughead and his dog, leading a pilot to good proprioceptive cues is Motoadve. Larry obviously has better proprioceptive cues now than when he started with the AOA indicator.

And as Denny and Wolfgang say, "watching the spot and the perspective in which it appears and its apparent motion" is helpful for "the process of stalling the airplane down." Pilots should find ways, or teachers of ways, to get to the proprioceptive cues. And at some point teachers, including devices, need to get the kids off the devices and out into the environment.

Fair points, Jim, but in the context of training proprioceptive cues and then removing crutches I think one could also refer to an airspeed indicator as a crutch. But nobody’s removing that one.

Better yet, we could all go back to flying open cockpits. There was a huge push-back from the aviation community at large against enclosing the cockpit in the early days. That’s an interesting read if you have time.

I’ve flown AoA on the T-6D and I love it. It’s a very useful tool, just like the other instruments in the cockpit. And I’d never remove it, even if I felt I had gained enough proprioceptive proficiency to not refer to it often. Because proficiency ebbs and flows over time. But AoA reporting (like airspeed indicating) is the same unless you change the hardware or calibration.

The arguments about “weaning off the tools and getting into the environment” sound eerily similar to the arguments against ADS-B in it’s early days. “You don’t need a box to show you traffic, all these pilots are missing the point to look outside!” Funny, I’ve heard some good stories from seasoned pilots now about a traffic cue on the iPad that helped direct their eyes to something they never would have seen.

If we expect pilots to glance at the airspeed indicator during the approach phase in between focusing outside, why is it so hard to grasp inserting a new tool in the scan?

[soapbox]

If there’s a tool available that you want to install, do it. It’s your money, it’s your airplane, and anyone that has anything negative to say about that needs to go search their inner selves to understand why they care so much about what someone else is doing if it has zero effect on them.

Hell, the FAA recognizes AoA as a useful tool to pilots, even in our little GA world. That’s got to say something. They couldn’t recognize a hole in the ground without a congressional mandate.

[/soapbox]

Good point generally about the airspeed indicator, Cam. Personally, I have not looked at one much, and certainly not on approach and landing, in fifty years. We are moving into an era where what I teach, yes the old plain wood panel, will be gone. Computers can fly airplanes better, in a sterile environment, than humans can. Backcountry, crop dusting, low altitude hunting and patrol, etc. will keep a small need for total non instrument maneuvering flight flying. I had only my eyes and the pipper in the Cobra. Dynamic proactive burst on target. I, however, did not own the battlefield like you and your devices did.

Hell, the FAA recognizes AoA as a useful tool to pilots, even in our little GA world. That’s got to say something. They couldn’t recognize a hole in the ground without a congressional mandate.

[/soapbox][/quote]

Cam, the FAA is in fact the very agency that concluded, without a trace of actual data, that big tires were the root cause of all the LOC accidents in Alaska. And, it took a separate federal agency (USFWS) and State agency (AST) to contract with a test pilot to prove them wrong.

Your other points are well taken, but the FAA has done ZERO flight testing or documentation as to whether or not things actually help. Which, of course, does NOT imply that they don’t help. But, when the FAA actually does some scientific research….I’ll listen to them.

I haven’t flown an AT-6, but it is in fact a somewhat different aircraft than what we’re flying……I seem to recall it was designed with a full time yaw damper to eliminate torque and p-factor forces, to more closely simulate its training target: pure jets. I think that’s a poor example to relate to a 182 or Cub.

But, ultimately, your point about it being up to the user is spot on. If they want one of these things, they are more than welcome to install one on their aircraft. I have no beef with that at all.

Frankly, though, I can fly my airplane significantly slower and quite safely by ignoring the one installed in my aircraft, and using my sensory cues instead. And, yes, the instrument is installed according to manufacturers instruction.


MTV

When the FAA was making the decision, there was ample data available to them from the US Navy. Naval aviators routinely rely on AoA instrumentation to perform what I would consider to be the most challenging, most difficult, and closest to "zero margin for error" approaches and landings in aviation – carrier landings. Ask any Navy / Marine pilot if they would give up their "crutch" (AoA)... I've been told by several of them that it was the one instrument they could not live without...

I am a former Army instructor pilot, and as a "research exercise" was once tasked with attempting to land an OH-58 Kiowa on a soon-to-be-retired carrier just offshore of San Francisco Bay. It was incredibly difficult to make a stabilized approach to a landing zone that was moving in three dimensions at the same time (ship's headway, lateral rolling, and pitching up/down slightly), and dealing with the massive wind "burbles" caused by the ship's superstructure. And I had the luxury of being able to ignore the fact that a fixed-wing approach would have been offset because of the angled deck. Plus, I was doing it on a CAVU day, well within range of safe landing spots on the shore. I'm sure the pucker factor would have increased dramatically had I no alternatives to landing on that heaving deck.

Those Navy / Marine pilots who land on carriers on a regular basis have my utmost respect! They should have wheelbarrows supplied to help them carry their cohones around... The fact that they rely heavily on AoA to make those landings says it all for me...

[Thread Drift Warning] Observation – the hardest part (by far) for THIS helicopter pilot was the final 3 feet (landing from a hover). You had to observe the motion of the ship (up/down, along with the roll angle) and time your landing so that you touched down just as the ship reached horizontal level and maximum height. If the ship were "rising to meet you," you got a really solid smack in the butt (ie - hard landing). If it were "dropping out from underneath you," you wound up in "free-fall" until either you caught up with the falling deck, or it began rising to meet you. Either way, you got another really solid smack in the butt... I guess that's why Navy helicopters have long-travel hydraulic suspension and nice big tires instead of the straight skids the Army helicopters came with... (And makes me wonder about the Marine pilots who fly landing skid equipped Cobras off those ships...)

mtv wrote:Cam, the FAA is in fact the very agency that concluded, without a trace of actual data, that big tires were the root cause of all the LOC accidents in Alaska. And, it took a separate federal agency (USFWS) and State agency (AST) to contract with a test pilot to prove them wrong.

Fair point Mike. That was a pretty boneheaded conclusion.

mtv wrote: I haven’t flown an AT-6, but it is in fact a somewhat different aircraft than what we’re flying……I seem to recall it was designed with a full time yaw damper to eliminate torque and p-factor forces, to more closely simulate its training target: pure jets. I think that’s a poor example to relate to a 182 or Cub.

You’re not wrong there. It is different from a 182 for sure. But I think it’s similar in the ways that matter - it has fixed wings that stall at an angle of attack, it has thrust control, and “conventional” flight controls with no augmentation aside from the yaw damper (which would affect likelihood of entering a spin but doesn’t effect the wing stall itself).

mtv wrote: Frankly, though, I can fly my airplane significantly slower and quite safely by ignoring the one installed in my aircraft, and using my sensory cues instead. And, yes, the instrument is installed according to manufacturers instruction.

I’m not surprised! You’re a good pilot with a lot of experience! Is that significantly slower flight also below the white arc on the ASI? Or below the stall warning if you have one? Just curious.

You’d probably be a good candidate for calibrating your AoA a little closer to wing stall. But if that’s factory equipment on a TC airplane you may not have that capability.



Side note: traditional stall warning devices actually operate on AoA and not airspeed. But they’re calibrated with an additional safety factor so they don’t go off as the wings stall.

First, some folks here apparently keep insisting that these light aircraft devices are in fact comparable to the true AOA devices installed on military aircraft….as in jets.

But, look at the sensors on an FA-18, or any other jet that’s using serious AOA data. I’m pretty sure those aircraft ALL have more than one, single sensor. They may be mounted in pairs, either side of the nose, or out on each wing. Even a single sensor, precisely centered would be better than what these so called Angle of Attack devices provide.

Which is a sensor at ONE data point, we’ll out on one wing (about mid span). Now, I am not much of an aerodynamicist, but that implies that AOA is identical over the entire span of the wings (note the plural). That’s certainly the ideal, but that’s typically NOT how LOC accidents begin.

And, Cam…..that yaw damper on the AT-6, probably helps keep AOA relatively constant, span wise. Maybe. Never flown one-dang it! But I’m available.

Cam makes the best point of all, though: our pitot systems are technically an AOA system. If you look at the sensor on my airplane for the AOA gadget, it looks remarkably similar to a Piper Warrior pitot mast.

If these things wind your watch-install one. Just don’t believe for a moment that it’s the same as the system on an FA-18.

And don’t bet your life on it.

MTV

mtv wrote:
Cam makes the best point of all, though: our pitot systems are technically an AOA system.


MTV

No, I don't believe this is what Cam said. And I do not believe this is a correct statement.

Totally agree, Mike. It’s a single data point taken from one location along the span of the wing. Just like my pitot tube

Anyone who relies solely on one to save their life: that’s at the end of a string of poor decision-making.

I’d recommend their use as a tool (among many others such as: proprioceptive cues, training, experience, instruction, the ASI, etc.) to help during low-speed ops. Or even on climb-out.

Squash wrote:

mtv wrote:
Cam makes the best point of all, though: our pitot systems are technically an AOA system.


MTV

No, I don't believe this is what Cam said. And I do not believe this is a correct statement.

Squash is correct.

The majority of the AoA systems on the GA market use a differential pitot system to approximate angles so they look like a regular pitot tube. That’s accurate enough in the angles they’re designed to operate in.

There’s a few GA systems that use a true vane, such as the CYA-1000. This is similar to what the big guys use.

Our T-6Ds (sorry Mike, I can’t get you a ride. It’d be fun to get you up there though!) use a vane probe on the left wing only.

The Cessna “suck through a T-shirt to test it” reed buzzers and the electric switch type buzzers use AoA principles to operate. Specifically, as AoA increases the stagnation point on the nose of the wing shifts further down. Eventually it shifts far enough to activate the reed or the micro switch on the little tab which alerts the pilot that they’re nearing the critical angle of attack.

I think we're splitting hairs here. What does a pitot/static system actually do? It compares pressures-granted, in a variety of methods.

What does an AOA device do?

What is a "stall"? The wing, or some part of the wing, reaches and exceeds it's critical angle of attack.

Granted, the conventional stall warning, as Cam noted, is set to initiate at some point before the wing reaches critical angle. But, isn't the point of both devices to warn of an impending stall/critical angle of attack exceedence?

What am I missing? Not being a smart ass, (Though I am) just looking for wisdom.....as I said, I am NOT a very good aerodynamicist.

MTV

Mike - no worries, I haven't taken anything you've said as smart-assery. Hopefully I've been coming across similarly!

Airspeed indicators measure pitot (total pressure) and subtract that from static pressure. This gives the pilot information about the speed the aircraft is moving through a mass of air. Since the variables in the lift equation generally don't change much, we can use airspeed as an indicator to when the wings are approaching their critical angle. We can also use indicated airspeed to control the upper side as well, keeping us safe from the dangers that apply to speeds like Va, Vb, Vfe, Vle, etc. At higher wing angles (or large yaw conditions), the fixed pitot tubes many of us fly are subject to error. There's even error just in their normal operating range (installation error), but it largely doesn't effect operations so few platforms spend the extra money to apply the corrections (calibrated airspeed, or add DA to get TAS). We can approximate TAS by adding DA to indicated AS, and that's very helpful in navigation (or was, before GPS).

An AoA device measures the angle of the relative wind in relation to the wings' (or wing's, depending on the installation) chordline. This is a direct measurement that can be compared to the critical angle of that airfoil. It must be calibrated or electronically adjusted based on the wing configuration (like flaps extended or retracted). It can also help target best glide speed (occurs at best L/D AoA), or Vx/Vy as needed. They're not much good above that, though. AoA won't help you with structural concerns surrounding the various V-speeds. And it won't help you with navigation calcs.

Both devices can help warn of impending stall. There's errors and approximations in airspeed indications at higher AoA, but it's a useful tool for many other operations so it earns its way on the panel. AoA can be more accurate in stall warning, but has fewer uses so it wasn't largely fielded outside of the small community that needed it (mostly Naval carrier ops). Now that the tech is cheaper to acquire, AoA is becoming more prevalent as a tool to a much larger community, to include GA.

Thank you for attending my TED talk.

I bought an Alpha Systems Eagle kit for my 180. Anyone have any recommendations for an installer, preferably south central US?

The nearest installer listed on the website hasn't done one and says "there may be a learning curve." I know what that means. I prefer one who has done a few of them!

Thanks.

slowmover wrote:....The nearest installer listed on the website hasn't done one and says "there may be a learning curve." I know what that means. I prefer one who has done a few of them! Thanks.

Interesting that Alpha would list someone that hasn't ever done one as an "installer".

slowmover wrote:I bought an Alpha Systems Eagle kit for my 180. Anyone have any recommendations for an installer, preferably south central US?

The nearest installer listed on the website hasn't done one and says "there may be a learning curve." I know what that means. I prefer one who has done a few of them!




Thanks.

Install on a Cessna its pretty easy, takes one day, I think there are other planes that are more complicated, I would not worry about it if its a Cessna,

There is a vane system out there. Website is www.riteangle.com. If I were buying just an aoa system, that's probably what I'd buy. I talked to the guy once about getting it field approved for my 180 but didn't carry thru. I'm building a super cub but bought a garmin avionics system for it and probably won't bother to add an additional aoa system but if I decide to, it would probably be that one just cuz it's a vane.

Wayne

motoadve wrote:Install on a Cessna its pretty easy, takes one day... I would not worry about it if its a Cessna,

Thanks!!