What AoA indicators are available?

[FloridaMan]

I've read a handful of posts by 201er in regards to his AoA indicator. I was doing some maneuvering yesterday between 125 and 140 mph, 60 degrees of bank at around 500 lbs under max gross. I'm not the most proficient at those maneuvers and occasionally would have to correct for altitude, bank angle or airspeed deviation and I know in making those corrections I end up loading the wing a little more. A combination of getting slow while making up for lost altitude could be catastrophic with little warning. I felt like I was flying while missing one of the most critical pieces of information for the type of flying. 

 

It doesn't look like I can find any information on the SafeFlight SC-150 that 201er has in his plane, but Alpha Systems is doing a good job marketing their products. I don't like the LED indicator or what looks like the PWM control they use for dimming it, but their legacy display looks like a good fit for the cockpit as I don't have any space in my panel available. 

 

What are your experiences/recommendations for an AoA indicator?

[aviatoreb]

I don't know what is available, but I am planning on this one for a summer time install while I am out of town:

 

http://www.alphasystemsaoa.com/duplicate-of-elliptical-8-x-4-1/2-mounting-plate.html

 

I like that it comes with audio voice annunciator warnings - I feel like this is a major benefit to catch your attention in case you are ever momentarily stupid and loose track of how much slower you are going than you think in a critical phase.

[FloridaMan]

Wonder if they'd cut a deal on a group buy...

 

I found this in one of my open tabs. I've got a feeling it may have been one I opened while researching an old mooneyspace thread on the subject. 

 

http://www.liftreserve.com/

 

$450

[aviatoreb]

Wonder if they'd cut a deal on a group buy...

 

I found this in one of my open tabs. I've got a feeling it may have been one I opened while researching an old mooneyspace thread on the subject. 

 

http://www.liftreserve.com/

 

$450

 

Huh - that's a deal.  I do like the idea of an audible annunciator though.

 

I wonder how much one of these things would cost to install in hours from an avionics shop?

[FloridaMan]

Two separate comments that I poorly separated. I meant the alpha systems for the group buy. But that other one at $450 is a damned good price. The installation estimate is 4-12 hours according to their FAQ. I imagine it has a lot to do with how difficult it is to run the lines to your panel and whether or not it's heated. 

[FloridaMan]

That's what mine says. 99mph at max gross and 60 degrees.

 

Guys, look at this: http://www.ronleclerc.net/lift-reserve.html

 

Differential pressure sensors are < $20. I think a combination of that and a power and data connection to a PCB mounted at the probe and you could make one with a simple install for < $100 with a digital indicator. 

 

It's not exactly an AoA indicator, but here's a breathalyzer I made a couple years ago for Halloween. 

 

[David Mazer]

I had a lift reserve model in another airplane and it worked great.  The only problem I had is the indicator didn't make sense or look cool enough for the Mooney.

[M016576]

I've posted until I've been blue in my fingers on the merits of an AOA indicator- I'm purchasing one as soon as I get the cash together for it (unfortunately I spent all my aircraft funds on an overhaul last summer). I like the Alpha Systems indicators w/ voice discreets... Mainly for the ease of adjustment. Initially I wanted the baseline mechanical model (as it would be a totally redundant/self contained system), now I'm leaning more towards the upgraded models. Either way, I'm going to mount the indicator above the glare shield if I can, so it's in my field of view while I'm landing.

[Marauder]

I've posted until I've been blue in my fingers on the merits of an AOA indicator- I'm purchasing one as soon as I get the cash together for it (unfortunately I spent all my aircraft funds on an overhaul last summer). I like the Alpha Systems indicators w/ voice discreets... Mainly for the ease of adjustment. Initially I wanted the baseline mechanical model (as it would be a totally redundant/self contained system), now I'm leaning more towards the upgraded models. Either way, I'm going to mount the indicator above the glare shield if I can, so it's in my field of view while I'm landing.

I was right! You are part of the Blue Man group. Does anyone have an Alpha system in their Mooney and have videos of it in action? I had one incident that I wrote about in another thread and I am curious if it would have made a difference.

[aviatoreb]

I've posted until I've been blue in my fingers on the merits of an AOA indicator- I'm purchasing one as soon as I get the cash together for it (unfortunately I spent all my aircraft funds on an overhaul last summer). I like the Alpha Systems indicators w/ voice discreets... Mainly for the ease of adjustment. Initially I wanted the baseline mechanical model (as it would be a totally redundant/self contained system), now I'm leaning more towards the upgraded models. Either way, I'm going to mount the indicator above the glare shield if I can, so it's in my field of view while I'm landing.

 

There you have it from the guy who has landed on aircraft carriers.

 

I'm a big believer in voice annunciators - and for my book a human voice is much better than a bell or a whistle - we already have a stall horn and any further horns are too much like sounding like that.  I have a voice annunciator for my landing gear by p2audio, and it is set to say either "gear is down" in a low soothing voice if the gear is down and you slow to below 90kts, and it says "check gear" in an emphatic worried sounding voice if you slow to below 90 and your gear is up - meant to be a reminder for your gear but it also serves nicely if you were to slow below 90 when you think you are going faster.  I consider this to be a safety enhancement of this gear warning system that I had not anticipated.  So if I am going to get a AOA, and I plan to, I figure a further audio voice warning when approaching the critical angle of attack would not only be good for good landings to help to adjust your flare at a critical moment when it becomes more difficult to keep an eye on your instruments at every second, but also to keep you honest and flying when you really want to be flying.

[M016576]

If memory serves from my '78 J model's POH, at 60 degrees of bank and 2 gs the cruise configuration stall speed is around 100 mph. I don't remember about weight. So at 125 to 140 mph you should have a comfortable margin unless you are really manhandling it.

I don't mention this to discourage your AoA indicator purchase but simply because I realize that your "owner's manual" might not include this information.

Jim

I like this thread for two reasons... It brings up some great points-

First- I like how our mooney drivers are flying and thinking about how the envelope of their aircraft is changing.

Second- I like how they are realizing the dynamic nature of their flight envelope, and are so inquisitive that they want to know more. I like that our guys aren't satisfied with the answer "just fly 90-80-70 and you'll be safe". I like that our guys want to see where their wing will actually stall....

I watched a YouTube video of a mooney that takes off, turns out with too much AOB and stalls into a spin at about 150'. The whole sequence of events took about 30 seconds- and whoever was aboard that aircraft was dead.

How many times have you seen or heard of a pilot just a little too wrapped up... That wraps it up just a little more. Probably thinking to themselves "self... I'm going 90 kts... No danger of stall here! I'm going WAY too fast for that!" In reality, though, they are pretty darn close and getting closer to stall with every ounce of back-stick pressure....

I've said it before, I'll say it again- if you want to know the condition of your approach, the condition of your wings ability to generate lift, and the optimum approach "speed" (really angle) for a given weight: you NEED an AOA indicator. Everything else is just an estimation.

[M016576]

There you have it from the guy who has landed on aircraft carriers.

I'm a big believer in voice annunciators - and for my book a human voice is much better than a bell or a whistle - we already have a stall horn and any further horns are too much like sounding like that. I have a voice annunciator for my landing gear by p2audio, and it is set to say either "gear is down" in a low soothing voice if the gear is down and you slow to below 90kts, and it says "check gear" in an emphatic worried sounding voice if you slow to below 90 and your gear is up - meant to be a reminder for your gear but it also serves nicely if you were to slow below 90 when you think you are going faster. I consider this to be a safety enhancement of this gear warning system that I had not anticipated. So if I am going to get a AOA, and I plan to, I figure a further audio voice warning when approaching the critical angle of attack would not only be good for good landings to help to adjust your flare at a critical moment when it becomes more difficult to keep an eye on your instruments at every second, but also to keep you honest and flying when you really want to be flying.

I love the voice discreets! From a human factors standpoint they are a very effective way of "spreading the warning out". That's part of the reason why I like the more advanced AOA units!

[aviatoreb]

I love the voice discreets! From a human factors standpoint they are a very effective way of "spreading the warning out". That's part of the reason why I like the more advanced AOA units!

 

I love voice discreets too:

 

 

HAL: This mission is too important for me to allow you to jeopardize it.

Dave Bowman: I don't know what you're talking about, HAL.

HAL: I know that you and Frank were planning to disconnect me, and I'm afraid that's something I cannot allow to happen.

Dave Bowman: [feigning ignorance] Where the hell did you get that idea, HAL?

[FloridaMan]

Where is that departure AOB stall accident video? I couldn't find it. 

[M016576]

I'll see if I can find it- it was actually the video from a school playground close by the airport.

Edit- here's the link to an article that had the video imbedded about half way down: chilling stuff.

http://www.aviationlawmonitor.com/2011/07/articles/general-aviation/the-impossible-turn-and-three-mooney-crashes-in-two-weeks/

[Marauder]

So if I am going to get a AOA, and I plan to, I figure a further audio voice warning when approaching the critical angle of attack would not only be good for good landings to help to adjust your flare at a critical moment when it becomes more difficult to keep an eye on your instruments at every second, but also to keep you honest and flying when you really want to be flying.

 

That's an easy one... If you are married, this will sound familiar "Knock it off you blockhead, you're going to get us killed!".

[Marauder]

I'll see if I can find it- it was actually the video from a school playground close by the airport.

Edit- here's the link to an article that had the video imbedded about half way down: chilling stuff.

http://www.aviationlawmonitor.com/2011/07/articles/general-aviation/the-impossible-turn-and-three-mooney-crashes-in-two-weeks/

That video was chilling. So was the preliminary accident report: http://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20110718X33733&key=1 for the third accident.

Looks like the pilot had a gear up 3 months earlier in the plane (his total time was 8500 with 4000 in model). In the accident report, it says that someone on the ground saw the prop depart the plane.

[bd32322]

So I was looking at the alpha systems site. Why is the legacy kit so much more expensive than the rest? You'd think the other kits show a larger range of AOA values than the small legacy indicator, just because they have more blinking lights

[FloridaMan]

That video was chilling. So was the preliminary accident report: http://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20110718X33733&key=1

 

Looks like the pilot had a gear up 3 months earlier in the plane (his total time was 8500 with 4000 in model). The flight on the video sounds as if it was a checkout flight after the prop was replaced. In the accident report, it says that someone on the ground saw the prop depart the plane. 

 

That's the wrong accident from the video. As far as I'm concerned, if you lose a propellor, control surface or something major, you are now in the same position as a test pilot of an aircraft dropped into the air in close proximity to the ground. 

 

This is the accident caught on tape: http://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20090301X04523&key=1

 

This accident involved a field overhauled engine that gave issue on the takeoff roll on a 2600ft runway. The pilot only had around 850 TT and 50 in type (not being critical, I only have around 400-500 with 200 in the Mooney). It sounds like they were committed to the takeoff and had to follow through with it. The sad thing is he stall-spun into a field. 

 

Remember, the moment you have an engine failure, it is no longer your airplane. It belongs to the insurance company. 

[FloridaMan]

So I was looking at the alpha systems site. Why is the legacy kit so much more expensive than the rest? You'd think the other kits show a larger range of AOA values than the small legacy indicator, just because they have more blinking lights

 

That's what I was getting at. It looks like it'd be easy enough to make your own from the link I posted above, only, in my case, I would use a differential pressure sensor and use that data to drive an instrument as opposed to running hoses to my panel. 

[Marauder]

That's the wrong accident from the video. As far as I'm concerned, if you lose a propellor, control surface or something major, you are now in the same position as a test pilot of an aircraft dropped into the air in close proximity to the ground. 

Fixed my post, I was talking about the third accident. He had a gear up in the same plane and it looks like they just put a prop on it and he was test flying it. Did I read that right? Wonder what kind of engine inspection they did that would allow a prop to depart...

[M016576]

Fixed my post, I was talking about the third accident. He had a gear up in the same plane and it looks like they just put a prop on it and he was test flying it. Did I read that right? Wonder what kind of engine inspection they did that would allow a prop to depart...

You lose that 60 lbs way up there, plus all your thrust, and you're in for the (last) ride of your life...

That would be bad.

That video, though, is obviously an approach turn stall to spin entry. It never develops to a full blown spin because of terra firma intervention.... An AOA indicator would show the pilot exactly where his wing would stall... And assuming the pilot was looking at it, or had an audible alert, he could maybe have prevented the stall/spin entry (regardless of engine running or not). Now, the power off landing afterwards... That's up to him/her... But an AOA indicator in this particular scenario could have possibly saved this pilot and his/her passengers life for a few seconds longer...

[201er]

Remember, the moment you have an engine failure, it is no longer your airplane. It belongs to the insurance company. 

Unfortunately not true. If you have a mechanical engine failure and manage to land back at the airport in one piece, it's your problem but if you bang it up, then it's theirs.

[OR75]

I was doing some maneuvering yesterday between 125 and 140 mph, 60 degrees of bank at around 500 lbs under max gross.

 

I'd say that if a pilot was maneuvrering at that speed, bank and weight,  I would hope he knows he is nearing aircraft limitation without the need to look at an AOA and would not need to look at an AOA to see if he is 80% or 90% of lift.

 

I am not saying that an AOA does not bring supplemental safety info. I am saying that I can think dozens of features I could add in a plane to safety ... 

backup gyro

backup battery

backup vacuum

backup GPS

handheld radio

AOA

Fuel totalizer

Engine monitor

safety belts / airbags

Autopilot

second engine

a chute

move to a jet

....

[aviatoreb]

I'd say that if a pilot was maneuvrering at that speed, bank and weight,  I would hope he knows he is nearing aircraft limitation without the need to look at an AOA and would not need to look at an AOA to see if he is 80% or 90% of lift.

 

I am not saying that an AOA does not bring supplemental safety info. I am saying that I can think dozens of features I could add in a plane to safety ... 

backup gyro

backup battery

backup vacuum

backup GPS

handheld radio

AOA

Fuel totalizer

Engine monitor

safety belts / airbags

Autopilot

second engine

a chute

move to a jet

....

 

I have almost all those things - except a chute, a second engine, and a jet engine.  I do very much think a voice annunciator AOA might have saved this guy from the stall spin at low altitude.  To remind him to stop trying that before too late.  Then that would have saved him to at least try the alternative.  They say your chances are much better even to land in trees under control than to spin into the ground.

 

You forgot airbag seatbelts.  I want airbag seatbelts.  And since I have most of the things on your "add safety" list I opt to add an AOA.