Angle of attack indicator

It's a shame there aren't many old-style AoA indicators for sale any more. The ones with the blinkenlights don't interest me, and the "probeless" ones in the E5, AV-30, etc. are actually just simulators that try to guess your AoA from other parameters: they get close most of the time (but not always), since they're not actually measuring your angle of attack like a wing-mounted probe would.

This one seems to be the only retrofit, analogue, probe-based AoA easily available right, but I don't know how accurate it is (any PIREPs?).

https://www.aircraftspruce.com/catalog/inpages/liftmonitor.php?clickkey=7092
05-14964.jpg
 
I had the lift indicator on my last plane and loved it. The probe is adjustable so you can set it up however you want. It’s great and simple and need nothing to work but air.


Sent from my iPhone using Tapatalk
 
David Megginson said:
This one seems to be the only retrofit, analogue, probe-based AoA easily available right, but I don't know how accurate it is (any PIREPs?).

https://www.aircraftspruce.com/catalog/inpages/liftmonitor.php?clickkey=7092
05-14964.jpg
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I have one very similar to this one in the top left of my panel. Second experimental airplane I've owned that I installed one in. They work very well. I use it much more than the ASI for take offs and landings.

Here is a short video from my test flight days after the aircraft was first built. The video is not so great but you can see the gauge in the mid white section as I cross over the numbers. One notch in the red zone is where the tires chirp at an indicated air speed of 36 MPH:

The price that Spruce wants for one is quite insane as these are easy/cheap enough to build: http://tincantimes.dcsol.com/LRI.html
 
Stewartb said:
Garmin's G3X supports an AOA with nothing more than a $200 probe. I added one. Why not?
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That alone would make me pick the G3X over the E5 if I were choosing between the two (I'm not interested in either). The E5 just does the fake, simulated AoA as an extra unlockable feature from what I've heard, trying to guess the AoA from its GPS and pitot-static inputs.
 
IMG_20181107_145631752.jpg I put a Lift Reserve indicator in my old Cherokee and used it often. I trained with and calibrated it to my liking. InAir Instruments is closed now, but the lift indicator is practically the same thing, so I installed one on my Mooney Super 21. The Mooney wing is different so I calibrated it differently and I use it slightly differently but I use it a lot too.

These devices are very accurate at low airspeeds near the stall when proper AOA can be critical. In my Cherokee it opened up a whole new realm of low maneuvering speeds. I have actually climbed with two people at 40 MPH IAS! AMAZING!! The Mooney wing is not as forgiving and I don't gain much low speed performance, but I can climb much steeper on initial takeoff and get off the ground easily much quicker by using the lift indicator instead of the ASI.

All these instruments require that final calibration be done by the pilot. There are a couple of ways to do this. In the Cherokee I did a slow flight stall with some power on, and noted the LRI needle position when the stall buffet began. I then landed, adjusted the probe and tested again. I put the needle of the LRI at the start of the buffet on the line between the white and red zones. It took three flights to get it dialed in. I never had to change it after that and I flew it for 10 more years. With practice I could do steep turns at the bottom of the white arc with absolute confidence!

In the Mooney the same stall approach seems to lead into a porpoising motion, so I tested for best angle of climb speed and set the needle right between the green and white band, so that the bottom of the green band is AOA for best angle of climb and the white band is in the back side of the power curve. With this set up the stall occurs about half way into the red band but the top of the red is not stalled... yet. Stay out of the red and stay safe, bottom of the green is best angle of climb. I easily liftoff in the half white zone then hold at the bottom of the green as the speed increases. Wow is that steep! I usually lower the nose a notch or two so I can see out the front and gain some speed because I am slower than Vx, but still climbing and still in complete control of the airplane.

In order to get the best use of the Lift indicator you have to calibrate it and TRAIN with it. If you do you will be pleased with the results. I hope this helps.

Have FUN! Fly SAFE! Petehdgs.
 
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William Pete Hodges said:
View attachment 91620 I put a Lift Reserve indicator in my old Cherokee and used it often. I trained with and calibrated it to my liking. InAir Instruments is closed now, but the lift indicator is practically the same thing, so I installed one on my Mooney Super 21. The Mooney wing is different so I calibrated it differently and I use it slightly differently but I use it a lot too.

These devices are very accurate at low airspeeds near the stall when proper AOA can be critical. In my Cherokee it opened up a whole new realm of low maneuvering speeds. I have actually climbed with two people at 40 MPH IAS! AMAZING!! The Mooney wing is not as forgiving and I don't gain any low speed performance, but I can climb much steeper on initial takeoff and get off the ground easily much quicker by using the lift indicator instead of the ASI.

All these instruments require that final calibration be done by the pilot. There are a couple of ways to do this. In the Cherokee I did a slow flight stall with some power on, and noted the LRI needle position when the stall buffet began. I then landed, adjusted the probe and tested again. I put the needle of the LRI at the start of the buffet on the line between the white and red zones. It took three flights to get it dialed in. I never had to change it after that and I flew it for 10 more years. With practice I could do steep turns at the bottom of the white arc with absolute confidence!

In the Mooney the same stall seems to lead into a porpoising motion, so I tested for best angle of climb speed and set the needle right between the green and white band, so that the bottom of the green band is AOA for best angle of climb and the white band is in the back side of the power curve. With this set up the stall occurs about half way into the red band but the top of the red is not stalled... yet. Stay out of the red and stay safe, bottom of the green is best angle of climb. I easily liftoff in the half white zone then hold at the bottom of the green as the speed increases. Wow is that steep! I usually lower the nose a notch or two so I can see out the front and gain some speed because I am slower than Vx, but still climbing and still in complete control of the airplane.

In order to get the best use of the Lift indicator you have to calibrate it and TRAIN with it. If you do you will be pleased with the results. I hope this helps.

Have FUN! Fly SAFE! Petehdgs.
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Thank you! That's great information. And I'll also mention that I love the mechanical stopwatch in the photo. :)
 
>>>>that I love the mechanical stopwatch in the photo. :) >>>

I just removed it as I don't use it much. I did have the dash clock sent out for repair... 3 Months before I have it back. Bummer. I am replacing all the engine instruments as they are now unreliable, so I'm removing the ADF & Loran and installing a GCR30 combo and air gizmos AERA 660 dock. It will be on the right side and angle mounted 15 degrees towards the pilot. I am keeping the original mechanical tach and adding a mini MP gauge so I have a complete mechanical backup to the GCR30 for power setting management in case of failure. I think it will be a real nice setup for me.

PS: Miller clock has finished the repairs to my dash clock and is shipping it out tomorrow!!
That is good service!!
 
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SPAGFIT
Situation, Power, Airspeed-Altitude-AOA, Gear, Flaps-Fuel, Instruments, Trim

IPAIDSAM
Identity, Position, Altitude, Intentions, Destination, Squawk, ATIS, Microphone

The IPAIDSAM acronym is part of the book Say Again Please about radio communication.

SPAGFIT is my rewrite of the GIFFTS check to put Situation up front because your situation defines how you set everything else. You set Power AirSpeed altitude trim fuel flaps and gear differently when you're entering the traffic pattern then say when you're leveling off for high-speed Cruise. SPAGFIT is designed so the situation defines everything else you do. It is a lot like the way I learned to fly but we didn't have an acronym to define it.

I have a set of SPAGFIT index cards written up for various common scenarios when I fly. These include engine start, taxi, run up, pre take off, climb, level off, descend, traffic pattern entry, short final, after landing checklist. They are handy mini checklists for any phase of flight.
 
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LRI_Meter.jpg Here is a picture of the LRI that I had installed in my Cherokee. I had a nice write-up about it posted on Wikipedia but the maggots over there removed it recently. Some of those guys live on Mars. They actually told me that Wikipedia was not a teacher and could not be used to teach people how to do something. My reply to them in writing was there is no other value to Wikipedia other than to learn, so they might as well get used to the fact that they are teaching people and that they are a teacher of at least some things. Needless to say that I am probably too much of a hard a** for that crowd. One Miracle at a time.
 
William Pete Hodges said:
View attachment 91626 Here is a picture of the LRI that I had installed in my Cherokee. I had a nice write-up about it posted on Wikipedia but the maggots over there removed it recently. Some of those guys live on Mars. They actually told me that Wikipedia was not a teacher and could not be used to teach people how to do something. My reply to them in writing was there is no other value to Wikipedia other than to learn, so they might as well get used to the fact that they are teaching people and that they are a teacher of at least some things. Needless to say that I am probably too much of a hard a** for that crowd. One Miracle at a time.
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Is the "non-primary instrument" placard mandatory with the installation? (Makes sense.)
 
Yes, in certificated aircraft as far as I know. The idea is that the pilot is responsible for checking its accuracy in flight for himself prior to relying on the device for actual flight maneuvers.
 
By the way, Miller Clock has finished the repairs to my dash clock and is shipping it out tomorrow!! They had initially said 2-3 months because they were backed up, but apparently they put the aviation clocks at the top of their list. That is fantastic service!! Thank you Miller Clock!!
 
I’m not getting it. Why do you need an AOA indicator? How is it that I have gotten along without one? Not being a wise guy. I just don’t understand why it’s necessary.

The video is sexy a romantic, but it appears that its just another person trying to sell something.
 
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MBDiagMan said:
I’m not getting it. Why do you need an AOA indicator? How is it that I have gotten along without one? Not being a wise guy. I just don’t understand why it’s necessary.
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Well, technically, you don't actually need one... Unless you want to fly closer to the lower edge of the flight envelope, or do steep slow turns with absolute safety. There is one big catch: It will only help you if you verify that it is set properly and you TRAIN with it enough to understand what it can do for you. An AOA meter will show you directly that any AOA can occur at any airspeed, especially the slower ones. When you are doing low speed maneuvers close to the stall, the AOA needle moves instantly as you move the yoke but the airspeed doesn't move for a few seconds as the airframe takes time to react. This means you can set the precise AOA you want instantly, independent of the ASI. It can help teach you a lot about how your airplane flies, and keep you out of trouble at the same time.

The US Navy adopted AOA meters for carrier landing approaches in the early 50s. The first year they cut the accident rate in half. The second year they cut it in half again. A carrier landing is obviously an extreme situation, but one that has to be done and an AOA indicator is the go-to tool for that type of application.
AOA has been embraced by the STOL crowd and you often find find AOA indicators on bush planes.

The Wright Brothers only had one instrument on their test planes, a rudimentary AOA meter. The first powered flight was only about 1 mph above the stall. The only way to do that is by using an AOA meter. With it they taught themselves and the rest of the world how to fly. That is reason enough for me to have one and train with it.

Hope this helps.
 
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MBDiagMan said:
I’m not getting it. Why do you need an AOA indicator?
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As already noted ... you don't need one and neither do I. But I use mine more than the ASI which, on my particular experimental, is electrically driven. If, for some reason, the ASI were to quit, I still have an excellent reference to use to be on an exact approach speed and know how much reserve lift I have available. No I don't need one ... but I want one and that's like the hokey pokey i.e. that's what it's all about. :cool:

https://www.faa.gov/news/updates/?newsId=83106

From the article:
The FAA encourages owners and operators of GA aircraft to install AOA systems in their aircraft.
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MBDiagMan said:
I’m not getting it. Why do you need an AOA indicator? How is it that I have gotten along without one?
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You've always had an AoA indicator — your stall horn. It's not a very sensitive instrument, though, because its only two indications are "Almost stalled" ("BLEEEEERP!") and "Not almost stalled" (quiet). People who do short-field takeoffs and landings, etc, sometimes find it helpful to have finer gradations.
 
MBDiagMan said:
I’m not getting it. Why do you need an AOA indicator? How is it that I have gotten along without one? Not being a wise guy. I just don’t understand why it’s necessary.
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As previously stated, you don’t “need” one. Just like you don’t need a GPS, Nav radio, autopilot, trim, or any one of a number of “unnecessary” devices. But they make our life easier or help us in some way or another.
 
William Pete Hodges said:
The US Navy adopted AOA meters for carrier landing approaches in the early 50s. The first year they cut the accident rate in half. The second year they cut it in half again.
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Is that prior or coincident to the angled decks? I’ve heard the latter cited as responsible for a significant decrease in accident rate but not AOA specifically. With LSOs monitoring, getting slow should have been preventable.
 
David Megginson said:
You've always had an AoA indicator — your stall horn. It's not a very sensitive instrument, though, because its only two indications are "Almost stalled" ("BLEEEEERP!") and "Not almost stalled" (quiet). People who do short-field takeoffs and landings, etc, sometimes find it helpful to have finer gradations.
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..... No, the 140 has no stall warning beyond the buffeting at the wing root that I can feel, and I’ve done my share of short field landings in her..
 
An AOA indicator is pretty cool equipment. Do you ever vary your approach angles? I do all the time. I can drag it in flat with power or come in steep at idle or come in steep and very slow with high AOA using power. Add obstacles and unfriendly winds to the picture, and make the strip short and narrow. Is it helpful to have an AOA indicator and audio annunciator on the ride down? Well yes, it is. Especially since I'm the one who calibrates it so I know precisely what it's telling me. Can I fly without it? Sure, but if I fly better and more consistently with it, why wouldn't I want one? Some days I'm more in tune with the airplane than others. Now I have an instrument that helps with that. There's no down side.

With my centered G3X the AOA display is easy to see in my peripheral vision while my eyes are looking outside. I can add Garmin's panel top indicator but with my panel configuration I don't need it. The audio alerts work like a stall horn. A little round gauge in the panel wouldn't be very useful for me.
 
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MBDiagMan said:
..... No, the 140 has no stall warning beyond the buffeting at the wing root that I can feel, and I’ve done my share of short field landings in her..
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Right, the earlier PA-28-140 has a red light in the panel instead of an audible stall warning. Is your U/S?
 
Boone said:
Is that prior or coincident to the angled decks? I’ve heard the latter cited as responsible for a significant decrease in accident rate but not AOA specifically. With LSOs monitoring, getting slow should have been preventable.
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I can't answer that because it wasn't part of that first AOA article I read. BTW I have not been able to find that article anywhere. That article discussed in relative detail why the Navy adopted AOA and the fantastic success they had using it. They cut landing accidents by 75% in 2 years. Really impressive results.
 
William Pete Hodges said:
I can't answer that because it wasn't part of that first AOA article I read. BTW I have not been able to find that article anywhere. That article discussed in relative detail why the Navy adopted AOA and the fantastic success they had using it. They cut landing accidents by 75% in 2 years. Really impressive results.
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That's amazing, but most of us don't land with the kind of margins carrier pilots do. I doubt it would make a significant difference in the GA accident rate — pilots who spin in on the base-to-final turn or on final are already managing to ignore the stall horn, buffeting, sloppy ailerons, and change in wind noise, so I'm sure they can ignore the AoA indicator just as effectively — but an AoA indicator would give more confidence to pilots pushing close to the edge of the envelope in STOL ops or aerobatics.
 
David Megginson said:
pilots who spin in on the base-to-final turn or on final are already managing to ignore the stall horn, buffeting, sloppy ailerons, and change in wind noise, so I'm sure they can ignore the AoA indicator just as effectively —
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I read that and thought, "sad ... but true!" Maybe we should add a a voice screaming,
"Terrain Terrain, Pull up! Pull up!"

 
I
William Pete Hodges said:
I can't answer that because it wasn't part of that first AOA article I read. BTW I have not been able to find that article anywhere. That article discussed in relative detail why the Navy adopted AOA and the fantastic success they had using it. They cut landing accidents by 75% in 2 years. Really impressive results.
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If you happen upon the reference, I’d be interested in reading it. As a former Navy pilot, it wasn’t one of the factors we were taught reduced that largely affected accident rates. We were taught that angled decks and NATOPS had the most significant impact. But I’m sure there were lots of improvements occurring during that time frame. AOA is definitely an advantage over airspeed.
 
Daleandee said:
I read that and thought, "sad ... but true!" Maybe we should add a a voice screaming,
"Terrain Terrain, Pull up! Pull up!"

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I liked this one posted previously. Maybe a sound less subject to complacency because genetic selection during our monkey days has weeded out most whose response was not fright (and should have been).

 
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http://dictionary.dauntless-soft.com/definitions/groundschoolfaa/Lift+Reserve+Indicator

I found the article I wrote for Wikipedia on the Lift Reserve Indicator. I sent them this feedback and asked that they sign my name to the piece. One Miracle at a time.

Good morning Dauntless. I am the author of this article for Wikipedia and I am pleased that it is still available on the internet. I am going to put a link to this page on the Pilots of America post thread "Angle of Attack indicators" which is ongoing as I write this to you.

You don't have to do this, but could you add my name to this as primary author of this piece? I wrote all but the first 2 sentences of this article. I also took the photo of the LRI shown on the newer LRI article now on wikipedia.
 
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MBDiagMan said:
As seen in my signature, I have a Cessna 140. Not a Piper.
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Ah. Sounds like fun (signatures aren't visible viewing the mobile version of the site in my phone). So agreed, your plane is too early for a mandatory stall warning device.

That doesn't mean it's not a good idea, though — I've landed (twice) with my airspeed indicator U/S, and while it was no big deal handling the plane by feel on approach, I wouldn't go around pronouncing that I've proven ASIs are unnecessary in airplanes.
 
D7A1CDE6-0FC9-4B07-9FBE-97D6D6D09825.jpeg

I didn’t say ASI’s are unnecessary. I do, however, believe that an AOA indicator is not necessary in all planes.

In my first training in an Aeronca Champ ca. 1992, my instructor said that I was fixating on the instruments and made me fly with a towel hiding the panel. I was a student pilot and lived to tell about it. I guess I defied death. Come to think about it I was flying with an attitude indicator that was based on the horizon, the real one.

I attached a picture of my Cessna 140 panel with sixpack and center stack. ASI in a 140 so yeah, I have no problem with an ASI. The top of the panel and the horizon make a very nice VFR AOA indicator. The next time I plan on landing on a carrier deck I’ll add one though.
 
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MBDiagMan said:
View attachment 91931

I didn’t say ASI’s are unnecessary. I do, however, believe that an AOA indicator is not necessary in all planes.

In my first training in an Aeronca Champ ca. 1992, my instructor said that I was fixating on the instruments and made me fly with a towel hiding the panel. I was a student pilot and lived to tell about it. I guess I defied death. Come to think about it I was flying with an attitude indicator that was based on the horizon, the real one.

I attached a picture of my Cessna 140 panel with sixpack and center stack. ASI in a 140 so yeah, I have no problem with an ASI. The top of the panel and the horizon make a very nice VFR AOA indicator. The next time I plan on landing on a carrier deck I’ll add one though.
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No panel instrument is necessary, strictly speaking, to fly a simple piston single in good VFR conditions. You can do it entirely by attitude and feel, like hang glider pilots do with every flight. We're talking about which instruments give the biggest additional benefit. I do not have an AOA indicator myself, but a lot of pilots are finding them helpful.
 
MBDiagMan said:
And those pilots should by all means install one.
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It is interesting to see how people respond to comments and ideas. My first instructor, a combat pilot in both Cobras and Apaches, told me that the ASI was a good indicator of stall speed but my sight and feel were as good if not better. He also said that the ASI was too inaccurate for true slow flight or short field landings and that my judgement and visual cues would always be inferior to a good sensor but this was the best we had access to.

If I had access to something that gave me a true sense of what the wing was feeling and not just a guess, I'd be all for it. Do you need it? No you don't. Many of my first flights was in a 39 Taylorcraft so technology wasn't a thing but dang, there are a lot of Hoovers and Yeagers out there these days.
 
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