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Alpha Systems AOA


What are others saying about AOA?

Alpha Systems AOA Customers are our biggest supporters.


"Love the Alpha Systems AOA I purchased last summer for my 172. Robust design. Easy installation. Flawless, reliable performance. Dramatic safety enhancement. Outstanding overall experience and results. It’s no wonder they’re now standard equipment on all new Cessnas. Probably should have been long ago. Thanks for a great product, and for your simply great after-sale support. Looking forward to seeing you again at Oshkosh. Best to all." - Ken Kellogg



“Chris from Wingnuts Aviation, setup my AoA for voice and it works great. It was talking to me on down wind, base and final, turning a steep left base with a quartering tail 10 degrees flaps she announced too slow. I looked at AS Ind and it was about 70. Increased AS to 90 and Flaps to 20, tuned final and readjusted To 70. Came back with too slow adjusted to 75 with rate of decent at 400, full flaps. Pulled power to land flared a little high was floating at about 5 feet. AoA kept repeating too slow until I touched down.

You can overlook/ignore a tone but not the voice it causes you to look. Recommend that installs use voice if possible.

JPI upgrade for fuel flow allowed me to confidently go LOP. Power Setting 30 MP 2300 RPM. Practiced it several times. LOP fuel flow at 9K was 14.7 at 145 IAS, 165 TAS. ROP 18.5 at 155 IAS, 175 TAS.

Conclusion: 10 knots not work 4 GPH. This can only get better at FL’se back with too slow adjusted to 75 with rate of decent at 400, full flaps. Pulled power to land flared a little high was floating at about 5 feet. AoA kept repeating too slow until I touched down.

You can overlook/ignore a tone but not the voice it causes you to look. Recommend that installs use voice if possible.

JPI upgrade for fuel flow allowed me to confidently go LOP. Power Setting 30 MP 2300 RPM. Practiced it several times. LOP fuel flow at 9K was 14.7 at 145 IAS, 165 TAS. ROP 18.5 at 155 IAS, 175 TAS." - Mike Respass


"The heads up display of the eagle is really great. Real saftey enhancement on trun to final, expecially for short field work. Don't even look at the airspeed on short finals. super safe!" - Michael Gerhardt



“I've been following Beech Talk AOA messages for a while. Looked at the different systems and decided on the Alpha Eagle. One system looked like my stall indicator & I didn't want to cut my wing. I can't remember why I didn't pick Garmin. It came down to Alpha & King. I found out that the King system was made by Alpha. I spoke to Mark Korin who owns Alpha. He's very accessible and even gave me his cell #. The King system display is older technology and remains lit all the time. The Alpha Eagle is not lit when parts of the display are not used. I chose the Alpha Eagle. Installation was done during my annual. After lots of thought and discussions with Mark & my A&P we decided to mount the heated probe on the left wing. Although I'm told mounting on either wing is okay the left wing is on the inside turn when making left traffic and most patterns are left traffic. We decided to mount the probe on the inspection plate next to the pitot probe and slightly closer to the fuselage. I can remove the pitot cover & probe cover at the same time. The initial setup is done at a 50 degree probe angle. Some Beechtalkers say they had to make multiple flights and change the angle to get it to calibrate. Mine calibrated on the first flight so I guess the wing position made it easy. We used the low profile probe (tube connections are low profile) in case I wanted to go near the bell crank but we didn't pick that spot. The electronics box was mounted on the left side of the pilots support seat under the spar cover. I had a blank panel at the bottom of the radio stack so we mounted the small control box there. Easy access for setup. After much deliberation and sitting in the plane I decided to put the Eagle display on the glare shield between the compass and windshield. I have my XM antenna between the AOA & vent ducts. It all fits. It's very visible in my peripheral vision and both the pilot and copilot can see it at the same time. There was enough room for the standard mount above the radio stack. The swivel mount would not fit. I believe they say install is around 10 hours. I'm not sure what it took as we were doing the annual at the same time. We didn't run into any glitches. I want my radio shop to hook up to the GMA 350 but you need audio to calibrate the system. I simply hooked the audio out and ground to a mini jack wire and plugged into the music- telephone input on the front of my audio panel. Audio on one channel is fine until the radio shop hooks into the back.


Now the fun part. I set the volume and picked the female voice that says "too slow". I think this was in reference to airspeed and not the pilot’s mental ability. Not sure about that yet. We calculated the aircraft weight and calculated the adjusted maneuvering speed. The interesting part is that you use 1.3 Vs (1.3 x stall in the clean configurations). I always land with flaps. Mark explained that if you calibrate with flaps and have them retracted you'll have less lift reserve than the system indicates and you don't want that. So how do you land based on a calibration at 1.3 x the clean stall speed. Instead of using the full donut you can use the top half of the donut when landing with flaps. (It works perfectly). We flew the plane and did the calibrations. Then we did some flying around -steep turn’s stalls etc. - pretty cool. My A&P really liked the audio saying too slow and decided he liked the system and mentally took it out of the gizmo category. By the time we were done my first AOA landing was at night (yes I am night current). I paid attention to both the airspeed indicator and the blue donut. They were both In agreement. First landing was nice and certainly not too fast. Dropped my A&P off and headed back to my home airport - MMU. Again I watched the airspeed and the AOA. Towards the flare I watched both the runway and the top of the blue donut. That was cool. Perfect speed on my second night landing. Today I'm might fly again and play some more. Do I like the Eagle AOA. Absolutely." - Arnie




"There is no question about it: After installing the Alpha Systems angle of attack indicator, my flying changed dramatically, but now, after enhancing the system with the Valkyrie heads-up display, my flying has changed forever.


In its original installation in the lip of my glare shield, the Ultra display was amazingly useful for precisely adjusting my angle of attack to achieve a final approach speed equivalent to 1.3 Vso. On short final, however, as my focus shifted exclusively to the runway ahead, the device was outside my field of vision. That meant that small pitch changes demanded by variable conditions --gusts, lift or sink -- left me with only an approximation of my initial angle of attack. The voice annunciations, of course, were a huge help. I knew that I wasn’t getting too slow (all red lights illuminated), however a slight pitch down might add an extra five knots, and with no immediate reference to the display, those small changes in AOA went unmonitored. While I was confident that I was in the “ball park,” I realized that my landing distance varied from about 1800 feet at best to 2500 feet. An extra three to five knots in the Mooney will make that difference, and while it matters little on a 3,000 foot or longer runway, the knowledge that I wasn’t as precise as I would like to be was troubling. It also meant that I would at times miss turn-offs and taxi farther than necessary to clear the runway.


Enter Valkyrie. In addition to the Alpha Systems angle of attack indicator, this is, without question, the best investment that I made in my airplane over the past 16 years. Using the Valkyrie head up display, which one can see through allowing the outside view to remain unobstructed, I can observe the angle of attack right through the flare and touchdown. The result is amazingly consistent landings and, in my case, predictable stopping distance within 200 feet of expectation. Now, I fly with confidence and precision into airports with runways that I previously considered marginal. I can turn onto final approach without shifting my view from outside and simultaneously monitor my angle of attack. I know that the turn is safe at all times. When gusty conditions present challenges on final, I can fly angle of attack exclusively without adjusting airspeed imprecisely by the 50% gust factor rule-of-thumb. That means flying with a greater margin of safety together with the assurance that one won’t use any more runway than necessary.


Pilots have been safely flying with reference to airspeed alone for a century or more. Certainly, one can do so with ease, so what’s the big deal? Consider that the POH provides approach airspeeds based on stall speed at max gross weight. What happens, however, when the plane is well below max gross weight, when one adds a passenger and baggage, when one burns off three-fourths of the fuel and attempts a landing on a short runway in a gusty crosswind. What’s the optimum approach and landing speed in all those cases? Sure, one can calculate a number, but how accurate will it be? In fact, many pilots exclusively use the approach speed designated in the POH for max gross weight. That will work in the air, but then one must accept the results on the ground in terms of longer landing distance and tire and brake wear.


Flying an approach by referencing angle of attack instead of airspeed changes all of that. Once the system is calibrated, one can consistently fly the exact same angle of attack on every approach without the need to calculate an airspeed adjustment for weight or conditions. That’s done automatically. The result is an immensely increased margin of safety, which means one can fly with far greater confidence and enormously enhanced precision. Until I tried it, I thought an AOA indicator was merely a frivolous enhancement. Then I saw the light, and it has been an absolute epiphany.


Now, I sing your praises on every landing: Thanks Mark for bringing me home safely!"- Mark P.



“Mark – Many thanks for going “above and beyond” to help me with the AOA installation issue I had with my Piper Meridian. Your willingness to spend telephone time with me on a Saturday until we isolated the problem was an example of customer service I have never before experienced with anything in my airplane, or with anything else for that matter! My dual indicator system is working perfectly, and I consider it to be a valuable addition to the Meridian. Thanks again for all your help.” – Jerry T. (Melbourne, FL)




Excited testimonial at EAA Airventure Oshkosh 2015.



“I have the Alpha unit in our C182, and we love the information and safety it provides.” – Brian S. (Satellite Beach, FL)"



"Recently I was approached in my hangar by a genuine CFII who spotted my ALPHA SYSTEMS ANGLE OF ATTACK PROBE and made the following statement: "That's the first time I ever saw an angle-of-attack on a Cessna. You must have a lot of money to spend."

This fellow had owned numerous airplanes, flown in Alaska for years, had an A&P license and a firm opinion on about everything. I explained that the investment was insignificant considering that it would instantly tell me how my Cardinal RG felt about flying at any particular moment.......REGARDLESS OF BANK ANGLE, GROSS WEIGHT, AIRCRAFT ATTITUDE, DENSITY ALTITUDE, AIRSPEED, OR MY LACK OF FOCUS ON ANY OF THESE LIFE –ALTERING FACTORS.

His educated reply was, "That’s what you have an airspeed indicator for." It is apparent that this uninformed attitude infects the minds of many sages in the small plane environment. It is exactly what the FAA promulgated for decades.........airspeed and attitude, and, oh yes, power setting. How NAIVE!

I started flying 55 years ago. During the twenty years I spent in the right seat of a Navy A-3 as a NAVAL FLIGHT OFFICER, I was introduced to an ANGLE OF ATTACK indicator. During over 250 day and night carrier landings in the GULF OF TONKIN, I had the very best seat in the "GOD, -CATCH -ME -A -THREE -WIRE" theater. The WHALE was the biggest aircraft to ever operate off a carrier.........the heaviest with the oldest engines and the slowest response times. Coping with the most demanding job in the pattern, these young egotists I sat beside all had one thing in common: they watched the ANGLE OF ATTACK INDICATOR as much as they did the BALL or carrier line up. Those who did not, heard the ego-crunching "BOLTER BOLTER BOLTER" and got another chance......with everybody watching.

Later, during various times flying aerial photography over rain forests in Honduras, mapping the Mexico City basin, photogrammetrically establishing the size of a dinosaur which walked down in a canyon south of La Junta, Colorado, 120 million years ago (think very low and slow), and mapping bumps in the runways of DFW and Chicago' O'HARE, I really yearned for that ANGLE OF ATTACK indicator. While I never saw anything as demanding or unforgiving as a pitching deck in a rain storm on a dark night in the South China Sea, I kept remembering hose Naval Aviators I respect so much and how they could not have done it without angle of attack indicators.

Finally, they are available to general aviation at a reasonable price. What made the FEDS so slow to endorse this, the MOST PRIMARY flight indicator? What does the indicator show? ....remaining lift?... wing chord angle to which wind? Who really cares?

When you are over shooting your base to final turn and want to know if you can SAFELY crank it around a little more, will you have time to mentally recalculate your gross weight, the current density altitude, and picture the graph in the POH that shows bank angle vs stall speed? How many of you do not carry a little extra airspeed when in doubt...... then wonder why your plane won't stop flying after the flare (or bounce)? Think about a short field landing when it is really necessary. Most all these considerations are alleviated by the ANGLE OF ATTACK INDICATOR.

Even if you are not landing on a carrier or cranking/banking your plane around to get another photo angle, everything you do in an airplane depends on how the wing on your articular airplane attacks that instant's relative air. The optimum angle of attack yields the most lift for the least drag. Want to know exactly the very best glide speed for your weight and density altitude? Got time to pull out the manual and compute it? ...probably not, if you are really interested in it! Want to know the perfect approach speed? Want to know when your airplane is about to stall.......regardless of everything else? Most airplanes buffet just prior....very distracting if you are not in an academic situation. My angle of attack indicator warns me visually and audibly before things deteriorate that far.

Why not know what is happening at a glance with an angle of attack indicator! When I asked several organizations for input from owners of an ANGLE OF ATTACK instrument, there was not one negative comment. There never will be from anyone who has flown with one.

Denny Donahue is a 73 yr old instrument-rated commercial pilot with multi-engine and sea plane ratings. He says he chose ALPHA SYSTEMS because they provided the indicator he liked best and had the most personal customer assistance department." - Denny D. (Topeka, KS)


"I have been very interested in adding an AOA to my Lancair Legacy.  I had no additional panel space and I didn't want a view obstructing instrument to be hard mounted on the glareshield. This year at OSH (2015) I saw the Alpha Systems AOA with the Valkyrie HUD.  I wanted to give it a try! To my knowledge, this was the first installation in a Legacy and we actually imbedded the HUD in the glareshield to allow for a little extra room to extend the HUD (45 degrees) before it touches the canopy. Mark and his team at Alpha Systems AOA were VERY helpful on multiple calls with questions on how best to get this done. 
Bottom line....with the probe set at the default of 50 degrees, I was able to get the system calibrated on the first try and the HUD is SUPER easy to read, even in direct sunlight and the voice prompts easy to hear and understand. I'm very happy with the system and the support I received." – Erik L. (Encinitas, CA)


"After installing, I calibrated the indicator to show just one yellow light above the blue light while at level flight with 20 degrees of flap extended.  That became my float lift point on takeoff. The 182 has Aeroset 3400s and the 185 has Edo 3500s.I was a Pilot Examiner, including seaplanes, for 40 years.  The AOA has really put the super fun back in float flying." – Anders C. (Seattle, WA)



"Dear guys at Alpha Systems, a special thanks to you and your company for the great AOA system that now resides in the AOPA sweepstakes Debonair N75YR. I understand the value this instrument and have been monitoring it on each landing (it's right where it should be in the view field). Assuming one keep's attitude control of the airplane, this one instrument out of all the other fancy gadgets could really save your life. I really like knowing its there, peace of mind. Thanks again to you and your staff for a great AOA system. From our family to you & yours" -Steve, L 


"I installed this on my 1966 V-35 Bonanza when I did my new panel. What I like most about the Alpha System is that it assists me in doing a much more accurate job of nailing my airspeed exactly where it needs to be for more accurate landings. When I change the power setting the AOA reacts faster than the airspeed indicator. One does not have to chase the airspeed indicator. Just set it up with three yellow lights and land. It works every time. I can’t imagine being without it. Thanks."– Steve Koontz (Livingston, MT)



"I received the AOA kit on Wed. 8/22/12, finished the installation and completed the in-flight calibration yesterday afternoon, 8/28/12. I'm extremely pleased with the system, and the ease of installation. I'm especially impressed with the quality of everything in the system and the detail included in the installation instructions. (I spent 40+ years as a Field Engineer, a manager and director for large scale computer systems, so I have a bit of experience with good and bad designs, and quality in systems.)

I did the installation myself under the supervision of an A&P. The A&P was also very impressed with the installation instructions; especially the example logbook entries, the suggestions on how to install it as a minor mod, and the specific situations that require a 337.

I ended up mounting the interface module above the headliner on the right wall above the co-pilot seat. This provided a near straight line for the sense lines to the probe on the right wing, and the three electrical cables all reached with ease to the display and to connections for power and the intercom. I mounted the display to the bottom of the glare shield just above the artificial horizon. 

I did the calibration flight yesterday. I was really surprised, almost shocked, that the 50 degree initial probe setting was right on, on the first try. I fully expected to need to do two or three flights to adjust the angle of the probe. I almost thought I as doing something wrong it was so simple; kinda felt cheated I didn't have to do the OAA setting several times to get it right.

I did do several stalls at various flap settings to see the differences on the AOA display for each. I'm already falling in love with Slow Sarah. Her "Getting Slow & Too Slow" reminders are fantastic.

I'll be putting together a summary in the next few days of the system, the installation and my impressions for the Cardinal Flyers Online electronic newsletter (CFO digest). It will take a few weeks before it gets sent out in the digest. There's been an ongoing discussion in the digest for the last few weeks about V speeds for L/D max, best angle of climb, the best speeds for maximizing distance, and the best short field & soft field speeds for the Cardinals. So, this summary may spark an interest with several members. As there's about 3,000 members of CFO, I suspect you may be hearing from some of them.

Thanks for the great product and the great safety improvement," -Jerry


"I am getting addicted to the AOA just from using it so far around Texas and the flight to Colorado. I'm using it for reference on final on all landings now, and find it consistently brings me down right on the numbers, with no float. I'm just putting it on Vs1.3 on final and as I cross the threshold, I'm at Vs1.1. As soon as I flare, it lands. It's really nice and consistent. And, it appears to be reducing my ground roll by 25% - 30%. 

I'm also finding it very useful on take-offs. I flew into Meadow Lake airport (KFLY) in Colorado. It's at 6900' MSL and has a runway that is about 6400' long. I took two friends up for short flights, one was my previous partner in the plane, and the other was my primary flight instructor from 35 years ago. Both days the density altitude was around 10,000', and we were near gross weight. On take-off roll, I've started rotating when the AOA display lights the first yellow LED which is Vx Max Take-off. This appears to minimize the ground roll, (due to not starting to rotate early) and makes for a very smooth lift-off. No more mushing into the air as sometimes happens during high DA take-offs. It also makes for a consistent abort reference point 1/2 way down the runway; no first yellow, time to pull the power back. 

The 2nd flight, from Meadow Lake into Centennial Airport in Denver with my old instructor, was interesting. He's a retired NWA captain with about 30,000 hours. He was real impressed with the AOA functionality, especially the display granularity showing multiple yellow's before Vs 1.3, the multiple red LED's for the stall speeds, and the stability of the display during approach. He really liked seeing how much margin there is above Vs 1.3 for use in high wind landings, and he also really liked the voice alerts. (He also commented about how great the plane performed on take-off from Meadow Lake.) Overall, he liked the AOA so much, he's thinking about ordering one for his RV8." - Anonymous