Do you have an angle of attack indicator (poll)

[FloridaMan]

Yep, General Yeager has basically told Mike he shouldn't be flying... 

 

Hey now; I wasn't saying that :-) I'm one of the guys who has been asking about them. 

 

I stumbled on this gem earlier today, thought of this thread and knew it would be gold to post. 

[yvesg]

Hey now; I wasn't saying that :-) I'm one of the guys who has been asking about them. 

 

I stumbled on this gem earlier today, thought of this thread and knew it would be gold to post.

Sorry about this Hugo, Chuck's opinion about AOA are already known by the forum users... check this thread:

http://mooneyspace.com/topic/8291-landings/page-4?hl=yaeger#entry90293

Yves

[bnicolette]

For those that are interested:

 

[aviatoreb]

Ok - now I have an angle of attack indicator....fully installed, flight tested and calibrated.

 

I got the top of the line electronic alpha systems unit, including voice annunciator, and heated probe.  Installed at BTV - nice people there.

 

Flight tests with "Hobie"in right seat from BTV - who is a 35,000 hr pilot with all sorts of small airplane, military and also airline and corporate jet pilot in all sorts of airplanes.  Am absolute pleasure to work with - he was right seat - it is definitely better a 2 man operation to calibrate the unit with lots of button pushing while while holding for 30 seconds just on the edge of stall.

 

As a not certified unit (but approved for install by special issuance by the FAA small aircraft division), you do your own flight testing. We did 3 iterations of flights, back to the AP to adjust the angle of incidence of the probe, then retest and recalibrate.    If it were a certified instrument, they would tell you for a mooney exactly where to place it and what angle to place it - instead we found the right angle through several test flights.

 

Finally we have the blue light to light at OAA - at 1.25 actual stall speed in the test configuration, clean.

 

Lights go from green (cruise) to several amber lights (getting slower) to blue (OAA) then the several red lights.  My early experience suggests that  1- maybe 2 in gusty conditions - amber lights showing over the fence, or over the numbers showing just the one blue is optimal approach speeds.  Maybe first red light but no blue for short field in smooth air.  

 

Voice annunciator says "getting slow" when all but one amber light go out (so ~1.3 to 1.35 stall) - and it says "too slow" when the blue light goes out and you are all red with 4 red lights showing (and actual stall is just as the 2nd to last red light goes out).  So short field just as the blue is going out/all red showing.  It is a little annoying that the "too slow" keeps repeating even during roll out until down to maybe 20kts but I am ok with that.  I like warnings in english.

 

We found the results to be quite repeatable during test flights.

 

Proof in the pudding that it seems quite a useful tool....on my way home today, for my home runway, runway 240 had winds 12 gusting 19 from 310.  Normally that is a bit tough - and now I know why....I was always probably a 3-4 kts fast when alone.  Driving down final on the AOA instead of airspeed had me just 3-4 kts slower than previously (since I was alone and therefore a bit lighter - but only 13 gallons burned off) - and what do you know - once straighted out, claire, just about zero float and she set down as nicely as I could ever wish.  A bit of stress edge off the annoyance of a decent cross wind.

 

Oh - its placed as a small round electronic dial just to the left of the airspeed indicator so I can see both with one eyeful during late landing flair.

 

All in all I like it a lot.

[DonMuncy]

Erik,

Photos, brand name, source, cost, installation costs, where it's located on the plane, holes in panels?, etc. All details appreciated. 

[carusoam]

Nice wrie-up, EB.

I'm with Don,

Send photos of what's involved.

Best regards,

-a-

[DaV8or]

That's what I thought about the Alpha systems. It's a lot of trial and error to do the calibration. It seems the accuracy of this instrument is dependent on how persistent and thorough you are during the calibration. I wonder how the other brands do it?

[DonMuncy]

I think the calibration is the worrisome part. My stall warning comes in very early, and I really don't worry when I hear it (in initial climb, for instance), because I know it is so far off. This is probably pretty dangerous. I am afraid that if you didn't set the AOA extremely carefully, you might end up with a similar situation.

[aviatoreb]

Ok - photos requested. Please see attached. Yeah - it was a glimpse into the experimental world that I was doing my own test flight engineering - it was sort of fun - as this was a small scaled project - but I wouldn't want to do a whole airplane! And the actual work was done by a real top rate avionics shop. If it were certified for this particular airplane, then they would have said exactly where to place it and exactly what angle of incidence to place it. And it would have cost 5 to 10 times as much. I would have purchased a certified instrument perhaps if it were available, but none was available, and I consider this a really worthwhile instrument worth the trouble.

 

As I said, if I had not had the device wired to the audio panel, and also wired for heat/anti-ice the it would have been probably half the install price of 2.5k.

 

I got this unit:

 

http://www.alphasystemsaoa.com/round-2-1/4-panel-mount-display-kit.html

 

together with heated probe: http://www.alphasystemsaoa.com/12v-heated-probe.html

 

When was the last time you bought a new avionics device for 1.2k?

 

Oh - by the way, when I called alpha systems and told them I had a mooney - they thought I needed the pressurized unit - because some M22 owner had purchased one before me!! Who was it?

 

In pics you see the position of the sensor on an inspection panel relatively far out on the wing to make it free of propwash. The AOA indicator display is just left of my IAS indicator. Here it is shown at turn on, where all the lights display then go off as a start up sequence. I like this position for two reasons. One it fits and in fact I had an inop radar altimeter in that hole - which I decided I was not going to fix (never worked on my watch - I couldn't decide if to fix it or not.. but with GPS altitude warnings it seemed a bit redundant). Then also being right next to my IAS, I could see both IAS and AOA in one quick eye full. Actually, I have flown a good bit again today - to Syracuse, to Saranac Lake, and around home....I am really liking the AOA. I landed at all different weights (heavy with four seats full (two were children)) to light (just me) and yes, the readings seem very very consistent to give me very gratifying landings reliably customized to my given weight.

 

An aside - at SLK some very very expensive wedding was going on today....and there were more than a dozen big big jets on the field including a brand spankin' new gulfstream G6.  My Mooney looked positively puny! :-)

[aviatoreb]

I think the calibration is the worrisome part. My stall warning comes in very early, and I really don't worry when I hear it (in initial climb, for instance), because I know it is so far off. This is probably pretty dangerous. I am afraid that if you didn't set the AOA extremely carefully, you might end up with a similar situation.

 

It wasn't so bad - actually sort of fun - as a one time thing....as I said I would not want to test engineer a whole plane, but one instrument was fun.  I did it with Hobie from BTV who is a 35,000hr CFI/DPE pilot with all sorts of airline, military and aerobatic experience.  I felt quite comfortable with him.  I now know exactly where my clean, and each of the degrees of flaps stall speed is.  I am pretty sure my stall is a bit slowed by my VGs by the way.  I am stalling at 52IAS dirty which is slower than most rockets I think.  With Hobie, and for repeatability, we were holding it right before the very beginning of stall for 30 seconds at a time.  This alone was well worth the trouble to refamiliarize myself with slow flight in a more substantial way than I ever did during my PPL or any previous BFR.

[Alan Fox]

Here is the perfect angle....

[aviatoreb]

Here is the perfect angle....

 

But that's not a Mooney

[Alan Fox]

But that's not a Mooney

But neither is this...

[fantom]

On T-34C:

 

[Corvus]

I came across this and it reminded me of this thread.

http://www.iconaircraft.com/video-icon-aircraft-a5-angle-of-attack.html

[DaV8or]

I came across this and it reminded me of this thread.

http://www.iconaircraft.com/video-icon-aircraft-a5-angle-of-attack.html

 

That does sort of spell it out. As I recall, the founder and chief of Icon is a former Navy fighter pilot, so it comes as no surprise to me that he would want his plane to have an AoA indicator in it.

[DAVIDWH]

Correct me if I am wrong, but didn't Lindberg fly from San Diego to St. Louis then on to New York and Paris with only a time

 

piece and an Earth Inductor Compass?

[201er]

I came across this and it reminded me of this thread.

http://www.iconaircraft.com/video-icon-aircraft-a5-angle-of-attack.html

That's a great video. I know it comes off as a marketing piece but in my experience flying with AOA, I'd say they are spot on.

 

The other day taking off, my airspeed indicator started to dip way down. I use AOA as primary on takeoff and it was rock solid where it's supposed to be. Since I was in VMC and knew my pitch attitude had not changed and my AOA was consistent (and it wasn't gusty), I immediately diagnosed a pitot/static problem and did not chase the airspeed. Perhaps if the needle dipped the other way, without AOA I'd chase the speed right into a stall?

[carusoam]

David,

Lindbergh was clearly the best pilot in the world. In his time....

How does the average pilot compare to that, today?

I'd go with more tools is better in this case.

Welcome aboard,

-a-

[DaV8or]

Correct me if I am wrong, but didn't Lindberg fly from San Diego to St. Louis then on to New York and Paris with only a time

 

piece and an Earth Inductor Compass?

 

Well... he had a little more than that. Here's his panel in the Ryan NYP

[DAVIDWH]

You are correct, those panels in 1927 were high tech. To be fair, I think he would have used an AOA indicator if it were available.

 

Taking off with 450 gallons of fuel, they didn't call him "Lucky Lindy" for nothing.

[M016576]

On T-34C:

 

The good old days :-)

[aviatoreb]

Well... he had a little more than that. Here's his panel in the Ryan NYP

 

Is that his fuel switching system all those levers below the panel?  That looks more complicated than the left tank/right tank system we enjoy in our M20 Mooneys.

[DaV8or]

Is that his fuel switching system all those levers below the panel?  That looks more complicated than the left tank/right tank system we enjoy in our M20 Mooneys.

 

No kidding. This picture in it's entirety, was a pretty big image and I was too lazy to open up a program to re-size, so I did a screen shot and cropped down. I decided to include all the valves below because I think it's a testament to his accomplishment... and also further illustrates how crazy the whole endeavor was!  

[1964-M20E]

Is that his fuel switching system all those levers below the panel?  That looks more complicated than the left tank/right tank system we enjoy in our M20 Mooneys.

Yes Lindy had a complicated fuel system.  You would be hung today by the FAA and lawyers if you tired to pipe a fuel system like that looks like regular old pipe fittings to me.