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uvtreith(at)t-online.de
Guest

Posted: Thu Jul 24, 2008 6:48 am Post subject: Pneumatic Installation

Hi Friends,  

   

I need an advice for the following:  

   

In my Monowheel I have installed the Europa Aircraft Stall Warner, the Dynon D 100 and the Pitot-Static Device from Europa Aircraft.  

The Stall Warner needs suction for operating, so this will have its own line with beeper and suction pressure switch – that’s ok.  

   

I have also on both sides of the fuselage static ports, connected them together and got that to the Instrument panel. Therefore this will be my static line.  

Now I want to change the static tube of the Pitot-Static Device from Europa Aircraft to use it as Input for the Dynon.  

   

Is that OK?  

   

Thanks for help.  

   

Bruno Reith / UVT Reith  

Monowheel – nearly finished.    

   

   

   

  

   

       [quote][b]

davidjoyce(at)doctors.org
Guest

Posted: Thu Jul 24, 2008 8:27 am Post subject: Pneumatic Installation

Bruno, My Europa stall warner needs no suction. It simply works on the 

pressure (positive or negative) produced by the airflow going over its 

opening at different angles of attack, but perhaps you just meant that it 

needed its own pressure tube.  As to the pitot and static lines you can 

simply put in a T piece to work extra instruments like an EFIS. My Europa 

supplied pitot/static head happily supplies conventional ASI & Altimeter 

together with a Blue Mountain EFIS.  Regards, David Joyce, G-XSDJ

---

rparigor(at)suffolk.lib.n
Guest

Posted: Thu Jul 24, 2008 8:37 am Post subject: Pneumatic Installation

Hi Bruno



"I need an advice for the following:



Now I want to change the static tube of the Pitot-Static Device from

Europa

 	  Quote: 	
		   Aircraft to use it as Input for the Dynon.


	


Is that OK?"



I am a bit confused about your question. Not sure if you want to hook up

the Europa supplied static port to the Dynon static input, or hook up the

supplied Europa static port as a driver for the Angle of Attack (AOA)

input for the Dynon.



OK will answer both scenarios.



You can use Europa static to drive static input for Dynon.



You can not use the Europa static to drive the AOA.



I am not yet flying but here is how I will drive my AOA Dynon input:



http://www.europaowners.org/modules.php?set_albumName=album238&op=modload&name=gallery&file=index&include=view_album.php



Ron Parigoris

uvtreith(at)t-online.de
Guest

Posted: Fri Jul 25, 2008 2:54 am Post subject: Pneumatic Installation

Dear David, dear Ron,



First of all many thanks for your advices and input. 

So my point was to use the Europa static tube on the pitot/static device as

AOA signal for the Dynon. 

Ron, are you sure that the position of the Europa device is too far back?

Hundreds of Europas are flying with this system very successfully.

As my plane is completely ready, it makes no sense to cut another hole into

the wings. For the Dynon I will now open and clean the static tube, get a

sleeve over that and will extend with a 45° bended tube to a (better?)

position. Flight tests later will show the best lengths. 



Best Regard,



Bruno



-----Ursprüngliche Nachricht-----

Von: owner-europa-list-server(at)matronics.com

[mailto:owner-europa-list-server(at)matronics.com] Im Auftrag von rparigoris

Gesendet: Freitag, 25. Juli 2008 00:03

An: europa-list(at)matronics.com

Betreff: Re: AW: Pneumatic Installation






Hi Bruno



If you bend down static port after you remove bullet so it is at a 45 degree

down angle there is a chance you may get some usable AOA information when at

Factory position.  As mentioned in my album it is too far aft for optimal

performance because the true airflow will have become distorted because too

much wing is upwind (in other words airflow will begin to follow the bottom

of the wing).



If it is unacceptable you can move both the static and AOA (old pitot) to

position  shown in my album. BTW that position was carefully chosen and

allows for pitot/ AOA tubes to somewhat be protected when wing is on Factory

trailer.



Ron P.



BTW be very careful grabbing the tube for bending, you can easily crush it.

Visit -  www.EuropaOwners.org

rparigor(at)suffolk.lib.n
Guest

Posted: Fri Jul 25, 2008 8:19 am Post subject: Pneumatic Installation

Hi Bruno



"Ron, are you sure that the position of the Europa device is too far back?

 	  Quote: 	
		   Hundreds of Europas are flying with this system very successfully."


	


I know of no Europa that is flying successfully with a AOA probe in the

factory position. True there are many Europas flying with pitot and static

in the factory position, but AOA is a different beast.



If you read the Dynon install manual for the AOA it tells you the position

they want you to install it. They are also advocates to only use their

offered outrageous probe.



I am not certain that the AOA will not work in the factory position. I

plan on trying mine first in the factory position where I know at least I

have at least a pretty good chance of an accurate airspeed indication.



Off topic a bit but to tune a factory static port, an O ring can be

installed, I think neutral is ~ 1" aft of cross drilled holes, more

forward increases pressure, more aft decreases pressure (I may be a bit

off on neutral point??)



Back to AOA, I would suggest you try yours in the Factory position and

please let me know how well it works. My gut feeling is there is a chance

it may give some useful AoA information, but not complete.



For me if Factory position gives unacceptable AOA info, after I learn how

to fly with semi accurate airspeed info I will move it along with my pitot

and static to my new more forward position and deal with getting pitot and

static happy again. I am not thrilled to fly a new plane I am unfamiliar

with with airspeed and static that may be a lot more whacked than if it

were in Factory position.



You see the Dynon learns your airplane when you go into their learn mode.

For AOA it is a pretty simple concept, the more direct the air flows into

the AOA probe, the greater the pressure. Best location is 3 or more feet

in front of the lead edge of the wing where it is in free undisturbed air.

Dynons location they depict for location has it close to lead edge on

bottom where air has yet to be very disturbed at high AOAs. On the Europa

factory position it is aft of the spar, at very high angle of attacks

there will be more pressure compared to free air in front of lead edge and

not only that the air will become deflected and begin to follow the bottom

of the wing to make AOA not as accurate as out front.



Bud likes the idea of installing a very long removable AOA so it remains

in tact on ground and gives accurate info in the air. 



Sometimes no matter how smart you are, your prediction that something will

not work can be wrong. I for one am willing to give the factory position

for AOA a try knowing full well that at best it may only spew out some

useful information, not work totally accurate. If that is the case then I

thought it a worthy cause to plan for it not working when the tops of my

wings are still off. 



Yes it can be moved more forward with top of wings on, just much more of a

job.



Please let us know your results.



Ron P.

davidjoyce(at)doctors.org
Guest

Posted: Fri Jul 25, 2008 9:37 am Post subject: Pneumatic Installation

Bruno, I am with you on the pitot/static as fitted to the XS. It has served 

me well and gives speeds that correlate completely with GPS speeds, and 

actual time over a course, and with stall speeds.  On top of that the 

aerodynamics and the flight testing and development were the work of Don 

Dykin, who is as smart as they come in the aerodynamics world (if you hadn't 

heard before he was the Chief Aerodynamicist at British Aerospace and 

responsible for the design of the wings of the Airbus series).

Regards, David

---

josok-e(at)ukolo.fi
Guest

Posted: Fri Jul 25, 2008 12:19 pm Post subject: Pneumatic Installation

Just to add: The Dynon 180 on my XS has the static and pitot connected in parallel with analog backup instruments. I tried to use the stall warner input as AoA input for the Dynon and can report that it doesn't work. The AA system in the Dyson expects more pressure at higher angle of attacks, and of course the stall warner tube produces a lower pressure at higher angle of attacks. I agree with the opinion that the Dynon AoA tube is awfully big and heavy. Must look great on a 747. There is a good chance the tube bending system will work. 

A second thought is that i am not really interested in AoA, because especially in the Europa, the AoA varies greatly between flyable speeds between 50 and 150 knots. It's the stall that i am interested in, and that has little to do with the Angle of Attack. But please correct me if this makes no sense!



Regards



Jos Okhuijsen

Visit -  www.EuropaOwners.org

rparigor(at)suffolk.lib.n
Guest

Posted: Fri Jul 25, 2008 2:00 pm Post subject: Pneumatic Installation

Hi Josok



"It's the stall that i am interested in, and that has little to do with the Angle of Attack. But please correct me if this makes no sense!"



I am sure you understand the point it is that you are trying to make, but AOA has everything to do with the stall, so please elaborate as statement above makes no sense to me.



I think perhaps point it is you are trying to make is Airspeed has little to do with stall??



Dynon AOA will show you surplus of lift that is available before stall will occur at a given weight, and airspeed and angle of attack.



If all things are equal:



A low all up weight will be flying at less AOA than heavily loaded thus more surplus lift on lower weight



Holding altitude with steeper bank angle will rapidly eat into your excess lift available



The greater the airspeed the more excess lift you will have available



In other words you can't use your airspeed to determine very easily when you will stall, AOA can easily tell you when you will stall.



I fly the same 48" flying wing model between all up weight of 8oz in pure glider form, to a 3/4 horse power 100mph plus 80oz monster. It is the same wing and the same airfoil. Guess what, they stall at the same AOA! True straight and level the 8 oz glider may stall at 4MPH, and the 80 oz monster in a 75 degree bank angle holding altitude may stall at 50 mph, but it is the same angle of attack that both will stall. Thus even if I had airspeed available, unless I did complex calculations I would not know when stall would happen. All that said if you fly plane with bottom of wing at less than about a  18 degree angle of attack as compared to the horizon I will not stall.



Dynon AOA that is fully functional will tell you no matter what your airspeed is, what your all up weight is, what your bank angle is when you are getting close to stalling. I know I can fly a plane without such information, butAOA can be a useful tool.



Go ahead and overshoot base to final turn in a fully loaded Europa at a high density altitude with most aft allowable CG, and bank and crank low to the ground with increasing tailwind the lower you go (bad since your ground speed will be increasing and will increase your overshoot), get that plane to a 60 degree bank, just keep plenty of surplus lift being shown on the AOA and you are good to keep that wing flying. If you have plenty of surplus lift you could even be flying sloppy and skidding and you will not snap upside down. That may mean dropping the nose a lot lower than you are used to and having a much higher groundspeed than you are used to, but that's OK because you will not stall where you don't have time to recover, just drop nose and add power and increase groundspeed till AOA is happy. If flying at a safe AOA will not work and allow a landing just go around. 



Lower powered jets some private owners fly use AOA extensively.



Ron Parigoris

Visit -  www.EuropaOwners.org

mikenjulie.parkin(at)btin
Guest

Posted: Sat Jul 26, 2008 1:53 am Post subject: Pneumatic Installation

"A second thought is that i am not really interested in AoA, because

especially in the Europa, the AoA varies greatly between flyable speeds

between 50 and 150 knots. It's the stall that i am interested in, and that

has little to do with the Angle of Attack. But please correct me if this

makes no sense!"

OH Dear !!!!!  The AOA has EVERYTHING to do with the stall!!!



Regards,



Mike

aireupora(at)sbcglobal.ne
Guest

Posted: Sat Jul 26, 2008 9:24 am Post subject: Pneumatic Installation

That is what an AoA does.  It shows you where you are in relation to the stall.  Every wings stall about 18 degree to the relative wind.  The wind can come from any direction.  Up, down, straight ahead or up side down.  The AoA is giving you your angle above the stall or the degrees above a stall of 18 degrees.   Most fighter jet use it to get the slowest speed for the given weight and condition.  They will pick 14 degrees.  That gives you four degrees to play with

   

  Hope this helps  



Mike Parkin <mikenjulie.parkin(at)btinternet.com> wrote:

  [quote]--> Europa-List message posted by: "Mike Parkin" 



"A second thought is that i am not really interested in AoA, because

especially in the Europa, the AoA varies greatly between [quote][b]

grahamsingleton(at)btinte
Guest

Posted: Sat Jul 26, 2008 10:52 am Post subject: Pneumatic Installation

Jos

Stall ALWAYS occurs at the same AoA, never at the same airspeed. PLUS, 

the ASI will tell you you are about to stall when it's too late, you 

already have. AoA gives instant response and tells you AoA has changed 

so ASI is now going to change but not for 20 seconds or so. The airplane 

has inertia so does not change speed instantly.

All relevant speeds vary with weight, temperature, pressure etc but AoA 

does not, it is consistent.

Imho, ASI is a secondary flight instrument, useful for navigation, AoA 

is the primary one, or should be.

Graham

btw there are two stall conditions, flaps down and clean, not the same 

but you knew that anyway ,,,,,,,,,,,



josok wrote:

 	  Quote: 	
		   A second thought is that i am not really interested in AoA, because especially in the Europa, the AoA varies greatly between flyable speeds between 50 and 150 knots. It's the stall that i am interested in, and that has little to do with the Angle of Attack. But please correct me if this makes no sense!



 Regards



 Jos Okhuijsen

 Visit -  www.EuropaOwners.org

mikenjulie.parkin(at)btin
Guest

Posted: Sat Jul 26, 2008 12:04 pm Post subject: Pneumatic Installation

Thanks Rick.  Actually what I wrote was below the quote of Jos’s  that you attributed to me.  

Having spent a large part of my career flying fighters.  AOA is not used to ‘get the slowest speed for the given weight and condition’ but more to find the optimum Angle of Attack for a desired manoeuvre – landing, acceleration or optimum combat turn performance – whatever.  

   

Regards,  

   

Mike Parkin  

   

   

Do not archive.  

   

     

From: owner-europa-list-server(at)matronics.com [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of Rick Stockton

 Sent: 26 July 2008 18:22

 To: europa-list(at)matronics.com

 Subject: RE: Pneumatic Installation  

  

     

That is what an AoA does.  It shows you where you are in relation to the stall.  Every wings stall about 18 degree to the relative wind.  The wind can come from any direction.  Up, down, straight ahead or up side down.  The AoA is giving you your angle above the stall or the degrees above a stall of 18 degrees.   Most fighter jet use it to get the slowest speed for the given weight and condition.  They will pick 14 degrees.  That gives you four degrees to play with  

    

   

    

Hope this helps  

 

 Mike Parkin <mikenjulie.parkin(at)btinternet.com> wrote:  

  [quote]  

--> Europa-List message posted by: "Mike Parkin" 

 

 "A second thought is that i am not really interested in AoA, because

 especially in the Europa, the AoA varies greatly between    	  Quote: 	
		    http://www.matronics.com/Navigator?Europa-List 	
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keithhickling(at)clear.ne
Guest

Posted: Sat Jul 26, 2008 3:31 pm Post subject: Pneumatic Installation

For those interested, there is a good basic aerodynamics  section on AOA in 

John Denkers online book (Graham and Mike can obviously write their own 

books !):



http://www.av8n.com/how/htm/aoa.html#toc20



Advanced Flight Systems (Angle-of- Attack.com) make an AOA system that 

derives AOA from the pressure differences between 2 tiny pressure ports on 

the top and bottom surface of the wing, and the static and pitot pressures - 

no additional probes. It is much easier to install before the wings are 

closed, but they claim it can be installed in a completed aircraft.



I have installed this but am not yet flying, so can't comment on its 

accuracy, but I believe it is supposed to be quite good - I would appreciate 

comments from anyone who has used it or knows how it performs.



Keith Hickling,

New Zealand.

95% done, much less than 95% to go!

josok-e(at)ukolo.fi
Guest

Posted: Sun Jul 27, 2008 12:08 am Post subject: Pneumatic Installation

Thanks for the reactions, i stand corrected. While i have no doubt any more about an elaborate AoA system, i keep wondering about value the Dynon AoA part of the flight instruments. I should add that i like my D 180 very much. The installation procedure of the AoA part of the Dynon system calls for a position where: "the airflow over the probe is relatively undisturbed by the aircraft " and a series of stalls in different setups. Side slipping on a base to final turn is not one of them. Could be added though  Now, to refine the question from a flight safety point of view: Is it safer to rely on this AoA indication and alarm or avoid being on the edge of the envelope by a good margin in the first place? 



Regards,



Jos Okhuijsen

Visit -  www.EuropaOwners.org

keithhickling(at)clear.ne
Guest

Posted: Sun Jul 27, 2008 1:07 am Post subject: Pneumatic Installation

"Now, to refine the question from a flight safety point of view: Is it safer 

to rely on this AoA indication and alarm or avoid being on the edge of the 

envelope by a good margin in the first place? "



Jos,

As Ron pointed out, the AOA is the only thing that will tell you how far you 

are from the edge of the envelope. Under normal weight, density altitude, no 

bank, 1g, you have a good idea of this from airspeed, but as Ron pointed out 

with high weight, low density altitude, high bank angle and maybe leveling 

out from a steep descent (so high g), the critical angle of attack (ie 

incipient stall) will be reached at a very much higher airspeed. AOA allows 

you to track how close you are to the stall under all these conditions, so 

that you can maintain a good margin of safety. A stall warner only tells you 

when you get too close to the stall. And in theory at least AOA can provide 

other information about airspeed for best L/D ratio (best glide angle) under 

these varying conditions as well.



Keith Hickling,

New Zealand.

kheindl(at)msn.com
Guest

Posted: Sun Jul 27, 2008 6:19 am Post subject: Pneumatic Installation

 

 I can honestly say that I have never missed not having an AOA. It might be useful in a high performance aircraft with tricky flight characteristics or a jetfighter with HUD. In the Europa it is a gimmick. When I am close to the ground I don't want to be distracted by checking a bunch of instruments. I go much by the control feel and the sound of the airplane. The Europa audible stall warner works very nicely C and gives a little beep before touchdown.

 In a turn the wings have different angles of attack C so how is an AOA indicator going to help you C when the probe happens to be on the low wing ?

 In my glider wings I have installed a stall warner in each wing C with different piezo sounders. When soaring C it is quite common to do tight turns at low speeds.

 Just my opinion.

  

 Karl

  

 



<html><div></div></html>



 	  Quote: 	
		   Date: Sun C 27 Jul 2008 21:03:40 +1200

 From: keithhickling(at)clear.net.nz

 Subject: Re: Pneumatic Installation

 To: europa-list(at)matronics.com

 

 --> Europa-List message posted by: Keith Hickling <keithhickling(at)clear.net.nz>

 

 "Now C to refine the question from a flight safety point of view: Is it safer 

 to rely on this AoA indication and alarm or avoid being on the edge of the 

 envelope by a good margin in the first place? "

 

 Jos C

 As Ron pointed out C the AOA is the only thing that will tell you how far you 

 are from the edge of the envelope. Under normal weight C density altitude C no 

 bank C 1g C you have a good idea of this from airspeed C but as Ron pointed out 

 with high weight C low density altitude C high bank angle and maybe leveling 

 out from a steep descent (so high g) C the critical angle of attack (ie 

 incipient stall) will be reached at a very much higher airspeed. AOA allows 

 you to track how close you are to the stall under all these conditions C so 

 that you can maintain a good margin of safety. A stall warner only tells you 

 when you get too close to the stall. And in theory at least AOA can provide 

 other information about airspeed for best L/D ratio (best glide angle) under 

 these varying conditions as well.

 

 Keith Hickling C

 New Zealand====

 

 

 


	


  [quote][b]

paul.the.aviator(at)gmail
Guest

Posted: Sun Jul 27, 2008 6:46 am Post subject: Pneumatic Installation

Karl,



Spoken like a true glider pilot !  Feel the airplane, it is always

talking to you.



Paul



 	  Quote: 	
		  On Sun, Jul 27, 2008 at 9:16 AM, Karl Heindl <kheindl(at)msn.com> wrote:


	


 	  Quote: 	
		  I go much by the control feel and the sound of the airplane.



 Karl

grahamsingleton(at)btinte
Guest

Posted: Sun Jul 27, 2008 9:58 am Post subject: Pneumatic Installation

Jos, imho you never know what the margin is with your ASI, you always 

know with AoA.

Landing too fast will eventually cause a problem, you could end up 

busting your prop a thousand miles from home =-O

So AoA is safer, Mike?

Graham



josok wrote:

 	  Quote: 	
		    Now, to refine the question from a flight safety point of view: Is it safer to rely on this AoA indication and alarm or avoid being on the edge of the envelope by a good margin in the first place? 



 Regards,



 Jos Okhuijsen

mikenjulie.parkin(at)btin
Guest

Posted: Sun Jul 27, 2008 12:44 pm Post subject: Pneumatic Installation

Graham,



I am not sure what is the safer route.  I have never flown a low wing

loading ac with an angle of attack system, so I cannot say how useful it

would be.  Certainly in many jets it is the major source for performance

indication.  Having said that, with experience, for performance manoeuvring

I found that buffet was as good an indication as looking at the AoA

indicator/HUD. I guess it is 'what ever floats your particular boat'.



Personally with the Monowheel Europa, I tend to subscribe to Carl's view on

the problem.  I have the Factory stall warner which I have found to be

spot-on.  It gives an aural warning of impending stall in both

configurations.  As an added bonus it gives a good indication of an

approaching accelerated stall.



Approach speed and approach path are important, but I find that having

arrived at the flare in good shape it becomes a case of keeping one's head

out of the cockpit and landing the monowheel very much by feel and visual

reference.  Now if the stall warner sounds just before the tailwheel makes

contact slightly before the mainwheel - then it truly is a red letter day.



Regards,



Mike.



Do not archive.



--

josok-e(at)ukolo.fi
Guest

Posted: Sun Jul 27, 2008 1:07 pm Post subject: Pneumatic Installation

Hi Graham, 



You are probably right that a good AoA is better then ASI. However, i fail to see how a very clever algorithm, one bent pitot, one pitot and one static can form a reliable AoA. Side slipping for one thing will change the static pressure dramatically. On the other hand the Europa standard stall warner works great. Mine happened to be adjusted 5 knots before stall. I land with the horn coming on as confirmation that everything is fine. While i am fond of gadgets, i am afraid that too much help from them will be a hinder. Can't imagine that i take my eyes inside the plane to look at an AoA really. Instead of that i would like to develop my feeling for the plane, like Karl and Paul are suggesting. It's getting better all the time 



Regards,



Jos Okhuijsen

Visit -  www.EuropaOwners.org

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