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 General Technics CYA-100 Angle of Attack Indicator 


I recently easily made a 1500 ft turn off a 2500 ft runway.  I couldn't (really wouldn't) come in slow enough before the AOA was installed to do that.  This opens up an entire new category of airport for me.


For those out there that believe the ASI gives the pilot the same usable information as the AOA, IMHO, haven't flown with an AOA.  The conservative factor I carried before the AOA really meant I wasn't able to land as slowly, a safety issue right there, and that my base to final turns were always shallower than they needed to be.  We have been flying for a century now without AOAs but that doesn't mean we should if we don't have to. 


This design is so much cleaner than the Alpha System and takes up so much less room on the panel and behind it.  I was sold the minute I found it.


Let me commend you for a very ingenious design - very simple design allows for a great price point. Your design doesn't require plumbing pressure tubing through the wing so that is a great install savings too over the alpha systems.  I do believe your design allows such a low cost as it should convince even more people to give AOA a try, and the more the better - so you have done a great thing for GA inventing this for GA.


Mooney pilots don't seem to be stalling and spinning in the pattern all that much, only about 6% of Mooney accidents. What Mooney pilots do seem to be quite adept at is losing control on the runway (R-LOC). About 1 in 5 Mooney accidents is R-LOC related. As a CFI, one of the big issues I see is guys (and gals) simply flying their Mooney too dang fast crossing the fence. 1.3 Vso plus an appropriate amount for gusts is enough. (If you're doing it right 1.2Vso works well too.) The problem is that Vso is not a constant. There is a big difference between indicated stall speed with minimal fuel when you're flying solo and indicated stall speed at max gross weight. The only thing that's constant is the angle of attack at which the stall occurs. The problems occur when guys start adding unnecessary or inappropriate cushions to a speed that, at best, many are just guessing at. It becomes pretty easy for some guys to end up 5 to 15 KIAS too fast. That together with the low ground clearance Mooney wing and you can get a bunch of R-LOC incidents as that Mooney wing floats and floats and floats some more. All of that goes away with an AoA. The correct speed every time, no questions asked. 


I can only tell you I've flown with 3 different AOAs and this is the easiest to install and calibrate and has worked well and reliably.


I think my total installation was just a few hours.  Certainly less than 5.  Of course, I didn't actually install it into the panel nor is it heated but I can't image it taking more than another couple hours to install it in the panel from someone that knew what they were doing (meaning, not me). As far as calibration is concerned, it is a breeze and certainly simpler than the calibration I did on 2 previous AOA systems (Dynon and Lift Reserve).  It really is as easy as described.


My Mooney is in the shop for avionics work and install of the CYA-100. Not installed yet but the experienced guys at the shop were amazed at how simple the unit will be to install...no running pneumatic lines and no third box to locate.


I'm sure the advanced flight systems AOA is a fine product. The least expensive version is more than double the cost of the CYA-100. Advanced monitors differential pressure (Delta-P) to determine AOA, that's fine and works acceptably well as, but I prefer the more direct vane method. Especially at less than half the price.


I like to get the best price I can, though I'm willing to pay for better quality. In this case I'm not convinced the higher priced offering has commensurate value. Comparing the two AOAs, the display is similar between Advanced's "lower price" Sport model and CYA's display. The audio warning is different in that Advanced uses voice while CYA uses a warble tone - nod may go to Advanced here as I may prefer voice, don't know, but I can live with the warble tone as it's unlike any other warning in my plane. I think CYA's vane sensor is a superior method of determining AOA over 45 degree off-set impact pressure ports. The vane is used on the big iron and military jets for a reason, though they use a heated probe of course. Not concerned with ice, as I won't be flying my Husky in it. Besides, it's likely an iced up wing is going to stall at a lower AOA and higher airspeed than a clean one in any case, so without FIKI, and iced up, one's AOA indicator probably shouldn't be trusted.


I wasn't convinced initially, but since flying with one I really think they are a great safety feature. They would certainly prevent some accidents if they were standard equipment.


Did a third test flight yesterday. As it happens, with the CYA-100 upper set point between Vy and Vx, and the lower set point just above full flap power off stall, Vso 1.3 is right where the display changes from green to yellow, and Vso 1.1 is right where it changes from yellow to red. Cool! I really like this thing a lot - - and for less than 4 AMU small, it's an incredible value, IMHO.


Things "airplane" tend to cost far more than logic would dictate. We become conditioned to expect that I guess, still it's a hard pill to swallow when some bit of avionics kit costs ten times as much as any similar device for most any other market. The CYA-100 is a refreshing exception, selling at one quarter or less the price point of the rest of the pack. Frankly, being a little on the parsimonious side, the cost of other AOA indicators had me rationalizing that the ASI and my seat-of-my-pants were just fine, thank you. But Rip's pricing seemed most reasonable and so I decided to try one on the Husky. Liked it so much I purchased another for my Mooney. I used to think there were but two reasonably priced items in aviation - cleco fasteners and bungee shock cords. Not sure how Rip does it, but you gotta add the CYA-100 to that short list of "How can they sell 'em for that?" items.

When I had the Dynon D10A in the Husky I had the AOA function on but it was worthless.
I am planning the CYA to set the low limit at max weight and 20 of flaps. Once I am on short final the flaps go to 30 and 40 and I donīt need AOA any more. But in the mountains tight 180 turns from downwind to final, with no visual reference to a horizon, Im sure it will be helpful.


The Dynon AOA was not what I wanted and the lift indicator you have was not my favourite either, since both systems use the the pressure difference between the top and bottom of the wing (DP), and divide the result by total ram air pressure (Q). The equation DP/Q can be a measure of angle of attack, but I donīt like it.
Now, that CYA100 is real AOA indicator with a free vane. Should be top of the cream.


I can see its value in steep slow turns in the Mountains.


As far as AoA goes, I am looking forward for my CYA100. It will show valuable info in downwind turns in confined areas as well as on landing on very steep slopes ( more than 40% ) On landings like I mentions at high DAs ( more than 12,000 ft) full power for the flare is needed.


In sunlight it is easy to see and colors register discreetly in peripheral vision - you don't have to look directly at it. I calibrated upper speed at about 70 mph indicated, in the climb with no flaps. Low speed, just above stall break, level flight with full flaps. It's easy to re-calibrate if you aren't happy with either setting. But you do have to re-program both even if you want to adjust one. In all cases the display leds progress smoothly, no jittering back and forth even when control movements are very slow (smooth air, not sure how they'll do in turbulence). It seems like it doesn't take a lot of pitch change to move from one LED to the next, it's sensitive. If the display is green or yellow, you know you're not gonna stall. If the display changes from yellow to red and you continue to increase AOA, a stall is closely imminent. (This is dependent on where the "low speed" is programmed.) Overall I like it - so far. Good tool. Not to be used as a crutch and it won't do much in the way of making up for a lack of stick and rudder skill. But nice to see "were you are" under all conditions of loading, bank, and speed.