AOA installation

[PTK]

...The correct approach airspeed in my airplane, a Bravo, can vary as much as 10 knots on final depending on weight. Because of the above, I always calculate my landing weight on approach for "proper" airspeed, but having an AOA would be a much simpler...

Someone like you Don with your level of expertise is not the issue. You have the deep and broad understanding to handle the airplane at the edge of the envelope.

As an instructor I'm sure you'd agree that the number one problem students have is airspeed control and more importantly timely recognition and application of proper corrective action. Sometimes pilots don't know what they don't know and allowed a situation to evolve to the point of no return, AOA or not.

I worry about folks who are no where near your level and reading this stuff may think they can go out there buy an AOA ind and solve the problem. Instead they should be getting instruction on airspeed control.

I do not possess your level of expertise but I do have enough understanding to know there is no "easy button" to replace constant training and refining one's skills.

[DaV8or]

I am totally sold on the AoA indicator and it is on my very short list of things to add to the plane. However, I am still a little skeptical/unsure about the calibration method. To those that have done it, how easy was it and how accurately does it indicate an actual stall?

[carusoam]

It's funny, but I think we are in agreement with each other and saying the same thing....

(1) we get the same useable information with the ASI, but it requires additional memory, recognition, thought and mathematics...

(2) many of us have a tendecy to over-pad the target landing speed. Wind and gusts add to the padding...

(3) being able to heat the device will make good sense for winter in the North East.

The brain's ability to monitor and control airspeed is impressive. Precision flying requires a high level of multi-tasking with a significant amount of stress thrown in for good measure. Fortunately, everyone's brain is different. Some can perform calculations quicker than others. Some have tremendous memory capacity. Some handle stress better.

AOA: Definitely not a requirement, but not a bad idea either.

Question: How to be able to rely on it needs to be considered...(once calibrated, how dose the pilot know it is working properly before or while he is using it. Can he cross check against the ASI at a known point in flight, like in the traffic patern?

I've had the good fortune to fly with a pilot that has an AOA in his plane (an M20J). Every landing was soft, two wheels and holding the nose off. Could be the AOA, the pilot skills, or... the stanky cargo pants!

Best regards,

-a-

[rq3]

I am totally sold on the AoA indicator and it is on my very short list of things to add to the plane. However, I am still a little skeptical/unsure about the calibration method. To those that have done it, how easy was it and how accurately does it indicate an actual stall?

I can't speak for the other devices on the market, but my CYA-100 calibration is a simple push button, which can be removed after calibration. Basically, you fly at any speed greater than stall (typically Vx or Vy, but the choice is yours). You press the button and power up the CYA-100. That sets the upper, green LED. Then you place the plane in landing configuration, and slow to stall, or just above stall. Press the button twice. That sets the lower, red LED. The computer then extrapolates the angle of attack for the remaining 8 red, yellow, and green LED's. After that, the display is very repeatable under all conditions of weight, bank angle, g loading, what have you. It measures TRUE angle of attack (relative wind vs wing chord). The stall angle of attack is a constant for any given airfoil.

 

Rip Quinby

[carusoam]

Rip,

Welcome aboard and thanks for joining in the conversation.

Obvious questions: does your Navion have a CYA-100? Do you use heat for it in winter?

Best regards,

-a-

[rq3]

Question: How to be able to rely on it needs to be considered...(once calibrated, how dose the pilot know it is working properly before or while he is using it. Can he cross check against the ASI at a known point in flight, like in the traffic patern?

 

Excellent point! I can think of two methods for the CYA-100. After the unit is calibrated to your satisfaction, land the plane. Leave the AoA powered up, and move the vane until you hear the AoA warning, then mark the probe. In future preflights, you would expect to hear the AoA warning when the vane is rotated to align with your mark.

Or you could check it in flight by slowing to stall.

 

Rip Quinby

[Marauder]

(2) many of us have a tendecy to over-pad the target landing speed. Wind and gusts add to the padding...

I've had the good fortune to fly with a pilot that has an AOA in his plane (an M20J). Every landing was soft, two wheels and holding the nose off. Could be the AOA, the pilot skills, or... the stanky cargo pants!

Best regards,

-a-

 

Anthony -- you bring up a good question. How does the AoA work when you are dealing with gusty conditions? With an ASI, I add a portion of the gust factor in. Would I not need to do this any longer if I had an AoA?

 

As for your second point, I think the fact that he has flown close to 300 in the last year has probably helped him perfect his landings. I have seen him more times this year than some family members!

[rq3]

Rip,

Welcome aboard and thanks for joining in the conversation.

Obvious questions: does your Navion have a CYA-100? Do you use heat for it in winter?

Best regards,

-a-

Thanks, a. Yes, indeed, 5186K sports a CYA-100. And no, it isn't heated, although from what I am reading here that will be a priority. My philosophy has always been that if there's ice, I've got big problems that need addressing pronto!

 

Rip

[carusoam]

Yes...

Descending through clouds with ice built up on the wing, the AOA is now calibrated to an airfoil that has been changed. Typically we add some KIAS to the ASI for an additional buffer. Would we add something the same way to the AOA?

This is assuming the AOA is working properly without heat, it would probably be inop...?

Best regards,

-a-

[rq3]

Yes...

Descending through clouds with ice built up on the wing, the AOA is now calibrated to an airfoil that has been changed. Typically we add some KIAS to the ASI for an additional buffer. Would we add something the same way to the AOA?

This is assuming the AOA is working properly without heat, it would probably be inop...?

Best regards,

-a-

Absolutely. I would trust an iced up AoA as much as I would trust an airspeed indicator driven by an iced up pitot tube. In other words, not at all!

 

Rip

[Hank]

Absolutely. I would trust an iced up AoA as much as I would trust an airspeed indicator driven by an iced up pitot tube. In other words, not at all!

Rip

But my pitot tube, installed in 1970, has heat . . . so I can expect accurate readings. Still, descending through an icy layer is something I plan to not do. Ice happens, however, so how would I expect the C-my-A to work in the pattern after a brief icing encounter? Do I just hope it sublimates completely?

One installation question: is there a preferred location? Obviously it needs to be outside the prop, would a reciprocal location to the pitot work? Somewhere else?

[rq3]

But my pitot tube, installed in 1970, has heat . . . so I can expect accurate readings. Still, descending through an icy layer is something I plan to not do. Ice happens, however, so how would I expect the C-my-A to work in the pattern after a brief icing encounter? Do I just hope it sublimates completely?

One installation question: is there a preferred location? Obviously it needs to be outside the prop, would a reciprocal location to the pitot work? Somewhere else?

Hi Hank. If its iced, its non-functional. Your best bet on answering these, and other operational and installation questions, is to get the CYA-100 Installation and Operation Manual here:

http://www.ackemma.com/tech.html

Click on the "CYA-100 Installation and Operation Manual" at the top of the page.

 

Rip

[PTK]

An ASI is a measurement of speed, which based on computations which we can do ( and as Don Kaye said stall speed can vary by as much as 10kts in a Mooney depending on loading considerations, and this is how I used to operate also), so your ASI measurement is relative to a guesstimate of an unknown target speed.

Performance: Simply stated, I am landing more accurately, shorter (due to no longer compulsively buffering in a few extra knots, and more often.

Erik, yes its airspeeds and guess what they're derived from...AOA! So I'm not ready to dismiss my ASI as a guesstimate! On the contrary, I find calculated approach speeds based on landing weight very accurate.

On runway 26 in my home field I routinely land and very comfortably make the second turnoff which is ~1500 feet. And I could make it if it was shorter with some braking, which I don't want to do. How much shorter do you land? Just curious.

And yes, I have landed my Mooney with ASI covered. It's an excellent exercise.

[rq3]

Folks, I'm starting to feel a bit guilty here. I joined this forum to answer specific questions on the CYA-100, but reading over my posts it's beginning to look like I'm plugging my own commercial product.

I'd like everyone to have an angle of attack indicator, from whatever source, because I sincerely believe that they can save lives.

If I'm overstepped the "advertising" bounds of your forum, please advise!

 

Rip

[PTK]

Not at all Rip.

On the contrary, I for one thank you for sharing your expertise and participation and contribution on the forum.

[Marauder]

Folks, I'm starting to feel a bit guilty here. I joined this forum to answer specific questions on the CYA-100, but reading over my posts it's beginning to look like I'm plugging my own commercial product.

I'd like everyone to have an angle of attack indicator, from whatever source, because I sincerely believe that they can save lives.

If I'm overstepped the "advertising" bounds of your forum, please advise!

Rip

LOL! Love your honesty! Actually, let's turn the situation around. Any chance you would entertain a group buy price if some of us were to buy as a group?

Sent from my iPad using Tapatalk

[Hank]

LOL! Love your honesty! Actually, let's turn the situation around. Any chance you would entertain a group buy price if some of us were to buy as a group?

Rip--

Sorry, but we fly Mooneys because we're frugal. Some call us 'cheap b@stards' but I prefer 'frugal.'

But I could jump on a group discount for this, especially if it can be heated.

[David Mazer]

Somewhere above the question of calibration difficulty was aksed.  I've had three AOAs.  The first in a Dynon system.  Required several attempts to get it right.  When I was done, I was never perfectly comfortable I got it right.  The second was a Lift Reserve Indicator.  A very nice product but, like ALpha Systems, required numerous flights to accurately angle the probe.  I really didn't like the display for the Mooney but it was completely mechanical (no electrical at all) and was easy to install in my SeaRey. 

 

The CYA-100 was calibrated twice but I had to fly three times to get it right.  On the first flight, I had wired it into the master and it couldn't be turned on and off (required to calibrate is to start from off if I recall properly).  The second time, after I installed an on off switch, all went.  Unfortunately, I accidently pressed the calibration button on the ground when I turned on the system and it assumed I was calibrating it again.  The third time I was very careful to get as close to stall as I could control and that turned out to be the best so far.

 

With this calibration, the AOA warning always sounds before the stall warning but not by much.  It has been very accurate and I now KNOW where I am with respect to stall speed.  I would strongly advise adding an on/off switch.  The tone, while useful and important, is ver irritating as I taxi in and out and the switch solved the problem of making the tone so quiet I might not hear it or so load it was an irritation.

 

The heated probe would be nice, especially for you TKS equipped guys but how often do we really fly in icing?  Personally, and I've already made the choice to proceed, waiting for a heated probe means flying without an AOA instead.  Hardly a value trade off for the <1% situation of icing.

 

Rip, go for it, give them a discount and get more of them installing this great safety device.  After that we can talk about my next profession of AOA salesperson!

[David Mazer]

One installation question: is there a preferred location? Obviously it needs to be outside the prop, would a reciprocal location to the pitot work? Somewhere else?

On my Mooney, and I presume on most, there is an escellent inspection panel location just back from the leading edge and far enough out to be out of the prop wash.  It is the second inspection panel out from the fuselage.  The vane is so light and creates so little pressure on the plate it didn't even require reenforcing.  About as easy as it can be.  I drilled 3 holes in the panel and, even if I have to remove the vane, the holes are so small, they are meaningless.

[bumper]

But my pitot tube, installed in 1970, has heat . . . so I can expect accurate readings. Still, descending through an icy layer is something I plan to not do. Ice happens, however, so how would I expect the C-my-A to work in the pattern after a brief icing encounter? Do I just hope it sublimates completely?

One installation question: is there a preferred location? Obviously it needs to be outside the prop, would a reciprocal location to the pitot work? Somewhere else?

 

A heated pitot may remain accurate, though "iced up" stall speed would be unknown. Heated or no, I would think that carrying ice the AOA's calibration would no longer be accurate. Then there's tail plane stall speed to consider. 

 

bumper

[rq3]

Any chance you would entertain a group buy price if some of us were to buy as a group?

 

I would consider that, but it wouldn't be much of a discount, nor could I make modifications (like a heated probe) yet. I build these things by hand, in batches of 9 at a time. I don't have enough volume (yet) to outsource fabrication to China, so there isn't any "economy of scale" from mass production.

 

Rip

[bnicolette]

I have a question.  

These aoa devices I assume go on one wing and not the nose of the airplane?  I also assume then that the device only shows you the angle of attack for that wing?  I guess that would mean it would be representative of the other wing also but only in coordinated flight?

[rq3]

I have a question.  

These aoa devices I assume go on one wing and not the nose of the airplane?  I also assume then that the device only shows you the angle of attack for that wing?  I guess that would mean it would be representative of the other wing also but only in coordinated flight?

That is true. Interestingly, that's also why most AoA probes are mounted on the left wing. Most turns in the traffic pattern are to the left, so the left wing is turning slower (on the inside of the turn), and has a higher angle of attack. The difference, though, is very small. I've practiced the "impossible turn" at altitude, and the turn direction made no difference to the AoA display.

 

Rip

[Marauder]

I have a question.

These aoa devices I assume go on one wing and not the nose of the airplane? I also assume then that the device only shows you the angle of attack for that wing? I guess that would mean it would be representative of the other wing also but only in coordinated flight?

Now you have gone off and done it Brett! The FAA is going read your post and there going to make it a requirement that two of them are installed because 2% of all U.S. airports have a right hand pattern!

[Marauder]

I would consider that, but it wouldn't be much of a discount, nor could I make modifications (like a heated probe) yet. I build these things by hand, in batches of 9 at a time. I don't have enough volume (yet) to outsource fabrication to China, so there isn't any "economy of scale" from mass production.

Rip

Let us know what you can do. Perhaps we can drum up some business.