Do you have an angle of attack indicator (poll)

[Alan Fox]

The stall horn sounds before a stall , not at or during a stall , You could fly around all day long with the horn blaring , and not stall the airplane.... So the argument that the horn doesnt go off until you have screwed up is moot......

[Hank]

Flying at MCA with the horn squalling was required when working on my PPL, and has also been required when attending the MAPA PPP. She flies well that way, I just don't appreciate the control feel.

 

On the other hand, if the stall horn goes off as you are in the base-to-final turn, you may be toast. Thus the perceived need for AOA.

 

Good procedure, however, will prevent that from happening. My max weight variation [gross - (empty + me + 10 gals)] is about 25% of gross, giving a non-quantified change in Vso. [back in 1970, there was no "POH," and data on many things included in more modern POH's is scarce.] So I don't bank steeply in the pattern, I don't cross-control except when intentionally slipping in straight flight, and I don't worry about cutting turns tight because that requires steep banks and/or crossed controls.

 

Combining threads here, I rarely use the PC-disconnect thumb button in the pattern, the additional heaviness is a good reminder to make shallow banks. Reading Bennett's post above, AOA may not be ready for wide implementation in the GA fleet,either.

[PTK]

Flying at MCA with the horn squalling was required when working on my PPL, and has also been required when attending the MAPA PPP. She flies well that way, I just don't appreciate the control feel.

 

On the other hand, if the stall horn goes off as you are in the base-to-final turn, you may be toast. Thus the perceived need for AOA.

 

Good procedure, however, will prevent that from happening. My max weight variation [gross - (empty + me + 10 gals)] is about 25% of gross, giving a non-quantified change in Vso. [back in 1970, there was no "POH," and data on many things included in more modern POH's is scarce.] So I don't bank steeply in the pattern, I don't cross-control except when intentionally slipping in straight flight, and I don't worry about cutting turns tight because that requires steep banks and/or crossed controls.

 

Combining threads here, I rarely use the PC-disconnect thumb button in the pattern, the additional heaviness is a good reminder to make shallow banks. Reading Bennett's post above, AOA may not be ready for wide implementation in the GA fleet,either.

Now you're talking Hank. Now you're finally talking...

[aviatoreb]

You use the ASI as an "approximation" but you "validate" pitch attitude with it?

Can't have it both ways. If it's used as a validating tool then you use it! Why don't you use your AOA indicator?

 

Mike do you use the ASI or don't you? 

 

I don't consider knowing my air speed "irrelevant". If air speed is irrelevant than what is relevant?

 

If you use the AOA to decide if you need to stop increasing bank angle and to maintain Vx/Vy, then you are reacting. The point is to control the airplane to the bank angle, attitude and AS you decide to fly. 

 

Fly the airplane rather than the other way around.

 

It makes me wonder that the Navy test pilot active on our forum, the airline pilots on our forum, and the FAA are clear and unanimous in their support that an AOA is a very useful piece of safety oriented instrumentation even for our little Mooneys.  But the dentist is firmly against.

 

As I said, I had begun discussion with my avionics shop for an appointment to begin the process of installing an AOA even before this thread.  So....I am heading to Burlington tomorrow for them to make a preliminary analysis of my airplane and what would be involved.

 

Thank you 201er for the thread and pushing the point - while I was already 90% convinced this thread was just the kick in the pants I needed to follow through.

[201er]

Thank you 201er for the thread and pushing the point - while I was already 90% convinced this thread was just the kick in the pants I needed to follow through.

I think our dentist friend will take more than just a kick in the pants to see the light

[Hank]

I think our dentist friend will take more than just a kick in the pants to see the light

 

That's probably a good start, though. 

 

Are there any good ways around the calibration issues that Bennett discussed? does it vary by aircraft model or airframe, or does it depend on the actual installation? The last thing I would want is an inaccurate readout backing up the approximation I already get from the ASI.

[Bennett]

I am not the only one who has had trouble with calibrating an AOA instrument. A quick search on the

internet this morning found a couple of pilots who had calibration problems. In one case, the probe had

to be modified, and in another case, the angle of the probe had to be changed. I suspect that the

calibration instructions are more generic than specific to particular airframes. The Alpha site shows a

Cirrus specific plate for their unit, and I would be much more interested in a Alpha system if they made

a plate that exactly matches one of our under wing inspection plates, and then extensively tested the

functioning of their system. Two pilots reported mounting their probes in the same location - under wing (high wing Cessnas), out of the propeller airstream, and one had problems with calibration, the other

did not. Both liked the units, once everything was setup.

[aviatoreb]

I am not the only one who has had trouble with calibrating an AOA instrument. A quick search on the

internet this morning found a couple of pilots who had calibration problems. In one case, the probe had

to be modified, and in another case, the angle of the probe had to be changed. I suspect that the

calibration instructions are more generic than specific to particular airframes. The Alpha site shows a

Cirrus specific plate for their unit, and I would be much more interested in a Alpha system if they made

a plate that exactly matches one of our under wing inspection plates, and then extensively tested the

functioning of their system. Two pilots reported mounting their probes in the same location - under wing (high wing Cessnas), out of the propeller airstream, and one had problems with calibration, the other

did not. Both liked the units, once everything was setup.

 

Interesting Bennet.

 

So tomorrow morning I am going to my favorite region avionics shop - at Burlington VT.  I am leaning toward the alpha systems AOA - the more advanced one with voice annunciator and also heated probe - so the works.  What should I be asking them?

 

Or should I consider a simpler system, like one with an analogue needle.  I do like the idea of a voice annunciator to wake me to attention if I ever in error drift too close to near stall when I want it least and inattentive.

 

Or is there another brand I should look at?

 

How much back and forth for calibration is there once it is installed?

[PTK]

I think our dentist friend will take more than just a kick in the pants to see the light

Mike you're all over the place man!

"...airspeed doesn't matter." Really?

"I only occasionally cross reference the airspeed when I'm less busy..." Too busy to know your airspeed?

"I fly the pitch attitude and validate with the ASI." So air speed matters now?

"I have no idea how accurate the [AOA] calibration is." And you trust the thing?

"stalls in the pattern are one of the leading causes of death in the GA community." You say this with a straight face?

"The AOA indicator helps you learn to fly..." That's a good one! What's in that cool-aid?!

I asked you some questions in my posts. Also Brett asked you a very important question that remains unanswered.

I find it odd that you find so much to say and yet, for whatever reason, you haven't answered any of them.

I'd appreciate if you'd answer them, please.

[Alan Fox]

Mike , can I base jump off the roof of your 201 at the critical angle of attack , at 12500 feet , and get some floss from Smiles and his hottie hygenists on the way down at 9000 feet , and land at the restaurant at sky manor , and pick up two free prop pasties from Don after I land????

[PTK]

After all that now suddenly Mike is quiet.

 

Maybe he saw the light, like a deer caught in the headlights!

 

I didn't expect a serious answer anyway!

[fantom]

After all that now suddenly Mike is quiet.

 

I didn't expect an answer anyway!

 

More likely that Mike confirmed, “Never argue with an idiot; he will bring you down to his level and win from experience.” 

[201er]

^ Thanks

[Bennett]

For what it is worth, the AOA system in my DOVA - D1 was a Dynon unit (heated probe)that interfaced with

their SkyView glass screens. It had the chevron type presentation, and it was right alongside the

airspeed tape. Great place for it! Unfortunately, my calibration efforts yielded inconsistent results

over about 4 attempts, following Dynon's instruction. To be fair, I suspect that that the DOVA would be

hard to set up as it has a very thin, double tapered (totally flush riveted)laminar flow wing, with

stall characteristics that are sharper than that of our Mooneys. I am concerned with placement of the

Alpha probe, and that is why I would like to see them build a unit for the Mooney wing like they do

for Cirrus - uniform placement,and flight tested. Intuitively, I think that the placement is critical. For example, inboard or outboard of the airspeed probe, the stall warning vane, left wing or right

wing, how far back from the leading edge of a Mooney wing, etc. I don't want to be the test pilot for Alpha, or any other manufacturer.

I do think AOA indicators are a good idea, especially if they can be scanned at the same time as a ASI or tape for glass screens.

[jimosborn]

Although an AOA is a nice thing to have it will not help you in assessing how close you are to a stall condition. You could be doing 140kts IAS or 90kts IAS but the AOA will indicate the same for either one. With the air speed indicator you know you have that extra speed to overcome a stall condition before you turn to final. You can fly without an AOA but not without an ASI.

 

José  

Jose, with due respect (and I say that with all sincerity) your understanding of AoA is exactly backwards.  Unfortunately what you DON'T know about AoA is stunning, and that's not a put-down; rather it's that your education in very basic aerodynamics regarding angle of attack is sorely deficient.  Please, please, for the sake of yourself and your loved ones, do spend some time to truly study the relationship between airspeed, wing loading and AoA. 

 

With respect to AoA devices, just two weeks ago the FAA sent out a general aviation safety “fact sheet” identifying several technologies the agency says can help significantly curb the fatal accident rate.  The top two devices named are seat-belt airbags and angle-of-attack indicators.

 

Too, a liberal education on the subject is available here;   http://www.ballyshannon.com/aoa.html

 

Cheers!

[AmigOne]

Boy, you guys sure know how to push my buttons! I don't understand why every time this issue comes up that guys refuse to acknowledge the aerodynamic principles of AoA.

I'm not saying that there is anything wrong with using airspeeds, I'm just saying its not as accurate of a way to fly (and its more complicated). But most GA aircraft out there don't have AoA. And it seems that most GA pilots don't learn and/or understand what it means. My guess, as I've stated before, is because GA pilots, and people learning to fly, are more comfortable with an "airspeed indicator" than something that sounds ominous and is not immediately obvious like an angle of attack indicator. So some guys have huge heartburn even accepting the idea of it. But think about how much easier life is/could be if you have an AoA indicator, not to mention safer. Of course, all assumes you are trained to use it, and know what you're looking at. Just like Glass cockpits- if you don't understand how to use it, it won't do you any good! But if you do..... Life can be less complex, easier and safer. Again, just my opinion.

Talk about pushing buttons!!, a lot of baseless assumptions in these comments. I would start by giving my fellow pilots more credit about understanding AoA. And for me I'd say that if I have made it past 5K in GA airplanes of all shapes w/o AoA I think I can make it for the few hundred hours I may have left in my flying career w/o one.

[xftrplt]

José,

Jim is exactly correct. The ASI is important for V1, Vr, and Vf (etc.) but otherwise (at least in theory) AoA is determining.

Respectfully,

Dick

[jetdriven]

I'm in the camp that thinks expert instruction in make and model along with good airmanship is money better spent than AOA indicators and airbag seatbelts.   The Cirrus is an example of that, take a look at its accident rate. Membership in COPA cuts the accident rate in HALF.

[Bill_Carter]

Where would a fellow get some good Mooney specific training like it was mentioned about Cirrus?

[wishboneash]

If somebody is going to give me an AoA indicator for free, I will put it in. Maybe I will look at it from time to time 

[Hank]

MAPA does have a European branch for Bill in Belgium. EMPOA or something like that. Check out www.mooneypilots.com and see if you can find a reference or link. The Pilot Proficiency Program is very thorough, 16-20 hours in the classroom and 4 hours flying your own Mooney with an experienced CFII, doing everything that has been discussed.

 

It's a great transition program for new Mooney pilots.

[aviatoreb]

I'm in the camp that thinks expert instruction in make and model along with good airmanship is money better spent than AOA indicators and airbag seatbelts.   The Cirrus is an example of that, take a look at its accident rate. Membership in COPA cuts the accident rate in HALF.

 

I think it was even less than that:

http://www.cirruspilots.org/content/SafetyHowSafeIsACirrus.aspx

"In terms of fatal accidents per pilot, non-members of COPA are also six times more likely to have a fatal accident: COPA members had eight accidents among 2,900 pilots (1 in 362), non-members had 33 in approximately 3,000 (1 in 91)."

 

But that is a correlation study.  Does participation in COPA cause people to have a lower accident rate or does the sort of person who is caferful and have a lower accident rate also the sort of person who participates in COPA?

 

I bet the same would be true of Mooneyspace, and no matter - I am here and hopefully I and all of you friends enjoy a much better than average safety record!

 

Now, I don't see why a person can't get an AOA, airbag seatbelts (other than the FAA STC won't let me have one yet!!! Argh...) AND partake in continuing education and dual training.

[aviatoreb]

So follow up, I was at the avionics shop yesterday scoping out an install plan for an AOA in my Mooney.  We will put the indicator in the spot of the inop radar altimeter to be removed which is right next to my airspeed indicator.

 

Will do in the fourth week of June while I am away on vacation (by minivan) with my family.

[201er]

So follow up, I was at the avionics shop yesterday scoping out an install plan for an AOA in my Mooney.  We will put the indicator in the spot of the inop radar altimeter to be removed which is right next to my airspeed indicator.

 

Will do in the fourth week of June while I am away on vacation (by minivan) with my family.

Be sure to post pics.

[jimosborn]

Now, I don't see why a person can't get an AOA, airbag seatbelts (other than the FAA STC won't let me have one yet!!! Argh...) AND partake in continuing education and dual training.

 

Dunno about the seat-belt airbag but be aware that AoA systems DO NOT require an STC, not even field approval for the install; only a logbook entry by any A&P.

 

Took 'em a while but FAA finally figured it out and got that one right.  Please read the FAA Letter of Clarification

 

Cheers!