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AOA indicator poll.



 
 
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  #1  
Old May 19th 20, 08:49 PM posted to rec.aviation.soaring
Luc Job
external usenet poster
 
Posts: 2
Default AOA indicator poll.

Hi!

I have developed last year a solid-state AOA indicator, based on a
differential pressure measurement (total pressure/pressure at angle)

Undoubtedly, this is a primary flight instrument to me:

-It shows where you are aerodynamically speaking, independently of
all the variable parameters: Load, flaps position, airbrakes...etc, and
does not need a calculation or interpretation to check if you are
flying right or not... And if the display is well done you will have a
clear indication of the ongoing tendency towards a safe or dangerous
situation.

-It give me an accurate indication to adapt the flaps position to stay
at the best glide angle through the whole speed range.

-It is a good indication of the optimal attitude during winch launch
and can prevent a high speed stall at high load factor.

Some pictures of my development are available he
https://bit.ly/aoaindicator
On the video the blinking effect is induced by the camera, the leds
simply fade in or out gradually, only the red one blinks at stall angle
or if the AOA rate of increase will induce a stall within 2 seconds...
you can see that the instrument works as good as its free
alternative...

The present system includes:

-A 5 leds indicator, red-amber-green-white-blue. The corresponding
AOA for each led is programmed in flight with a push-button.

-An audio input and output: Instead of adding a warning while flying
at higher AOA than the maximum Cz (minimum sink rate), the
instrument hashes the audio output of the vario gradually, cutting
the sound at stall. This is an excellent indication that something is
wrong without adding noise... You can continue to watch outside
while climbing at the best speed, and avoid to enter a spin in the
middle of others.

-A serial i/o for software upgrade and continuous transmission of the
data to another instrument.

-An optional light sensor to adapt the luminosity to the ambient light
level... But the indirect illumination and a better reflector (in
development) has proved that it is probably unnecessary.

The only hardware modification is the installation of an angled
pressure port at a suitable place: angle is not critical, but flow must
be as undisturbed as possible. On the DG I've put mine under the
nose, about 170 mm from the tip, where I had access to the outer
hull from the inside. I drilled a 2 mm hole and glued a small
pressure chamber inside to plug a 4 mm hose. That's all.

Power drain is lower than 20 mA @ 12V, less on ground as no led is
switched on... So no switch, but an internal polyfuse to avoid any
dangerous current drain... So it is simply added to the (fused)
instruments circuit.

Now as the system proves to be functional and efficient it's time to
do something with it.

Many options are possible:

1) I can order and sell PCB's only, with a BOM and the software...
This is obviously the cheapest way... But components are mostly
SMD... So you need an oven or a lot of patience and skill... Up to
you to make a box adapted to your needs. Price should be about $10
including shipping.

2) I can sell a complete kit with all the components, PCB, software,
connectors and box... Components are not expensive except the 2
pressure sensors ($35 each)... So I should be able to make this for
about $150...

3) If you prefer a complete instrument, ready to plug-in (except the
pressure port installation) the price should be in the 300-400$
range.

All this depends obviously on quantity... So if I have 1'000 orders it
might be significantly cheaper.

At first I need to know how many people might be interested... And
what is the best option for you.

At least we can fly again in Switzerland and France... So it might
take some time for me to build a website for this product...

Luc JOB
DG-800B

  #2  
Old May 19th 20, 09:30 PM posted to rec.aviation.soaring
Jonathan St. Cloud
external usenet poster
 
Posts: 1,463
Default AOA indicator poll.

On Tuesday, May 19, 2020 at 1:00:05 PM UTC-7, Luc Job wrote:
Hi!

I have developed last year a solid-state AOA indicator, based on a
differential pressure measurement (total pressure/pressure at angle)

Undoubtedly, this is a primary flight instrument to me:

-It shows where you are aerodynamically speaking, independently of
all the variable parameters: Load, flaps position, airbrakes...etc, and
does not need a calculation or interpretation to check if you are
flying right or not... And if the display is well done you will have a
clear indication of the ongoing tendency towards a safe or dangerous
situation.

-It give me an accurate indication to adapt the flaps position to stay
at the best glide angle through the whole speed range.

-It is a good indication of the optimal attitude during winch launch
and can prevent a high speed stall at high load factor.

Some pictures of my development are available he
https://bit.ly/aoaindicator
On the video the blinking effect is induced by the camera, the leds
simply fade in or out gradually, only the red one blinks at stall angle
or if the AOA rate of increase will induce a stall within 2 seconds...
you can see that the instrument works as good as its free
alternative...

The present system includes:

-A 5 leds indicator, red-amber-green-white-blue. The corresponding
AOA for each led is programmed in flight with a push-button.

-An audio input and output: Instead of adding a warning while flying
at higher AOA than the maximum Cz (minimum sink rate), the
instrument hashes the audio output of the vario gradually, cutting
the sound at stall. This is an excellent indication that something is
wrong without adding noise... You can continue to watch outside
while climbing at the best speed, and avoid to enter a spin in the
middle of others.

-A serial i/o for software upgrade and continuous transmission of the
data to another instrument.

-An optional light sensor to adapt the luminosity to the ambient light
level... But the indirect illumination and a better reflector (in
development) has proved that it is probably unnecessary.

The only hardware modification is the installation of an angled
pressure port at a suitable place: angle is not critical, but flow must
be as undisturbed as possible. On the DG I've put mine under the
nose, about 170 mm from the tip, where I had access to the outer
hull from the inside. I drilled a 2 mm hole and glued a small
pressure chamber inside to plug a 4 mm hose. That's all.

Power drain is lower than 20 mA @ 12V, less on ground as no led is
switched on... So no switch, but an internal polyfuse to avoid any
dangerous current drain... So it is simply added to the (fused)
instruments circuit.

Now as the system proves to be functional and efficient it's time to
do something with it.

Many options are possible:

1) I can order and sell PCB's only, with a BOM and the software...
This is obviously the cheapest way... But components are mostly
SMD... So you need an oven or a lot of patience and skill... Up to
you to make a box adapted to your needs. Price should be about $10
including shipping.

2) I can sell a complete kit with all the components, PCB, software,
connectors and box... Components are not expensive except the 2
pressure sensors ($35 each)... So I should be able to make this for
about $150...

3) If you prefer a complete instrument, ready to plug-in (except the
pressure port installation) the price should be in the 300-400$
range.

All this depends obviously on quantity... So if I have 1'000 orders it
might be significantly cheaper.

At first I need to know how many people might be interested... And
what is the best option for you.

At least we can fly again in Switzerland and France... So it might
take some time for me to build a website for this product...

Luc JOB
DG-800B


That is wonderful. An AOA indicator is something that I would purchase for and ASG-29
  #3  
Old May 19th 20, 10:30 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 281
Default AOA indicator poll.

Cool, I did a cal flight in that area this weekend.


Made a new flap setting ring for the ASI. Added an inside piece of tape for the outside pitch string. In flight, added a dot to mark string position for best L/D.

Then checked to see if the center of each flap settings on the ring matched the dot. They did pretty well.

I've been thinking about an electronic AOA for sensing the H&V air direction. I have an Ardinuo and diff transducer rigged to a machined nose piece with a pitot and angled port. It can sense a 1% angle change on the bench with a wind tunnel (some call it a shop vac). But I'm not sure if it would be any better than normal instruments already there.

Your picture shows you also have the pitch string. Have you added the dot and checked to see if the electronics stay's green at different speeds but still on the dot?



  #4  
Old May 20th 20, 01:39 AM posted to rec.aviation.soaring
Michael Opitz
external usenet poster
 
Posts: 318
Default AOA indicator poll.


Many options are possible:

1) I can order and sell PCB's only, with a BOM and the software...
This is obviously the cheapest way... But components are mostly
SMD... So you need an oven or a lot of patience and skill... Up to
you to make a box adapted to your needs. Price should be about

$10
including shipping.

2) I can sell a complete kit with all the components, PCB, software,
connectors and box... Components are not expensive except the 2
pressure sensors ($35 each)... So I should be able to make this for
about $150...

3) If you prefer a complete instrument, ready to plug-in (except

the
pressure port installation) the price should be in the 300-400$
range.

All this depends obviously on quantity... So if I have 1'000 orders it
might be significantly cheaper.

At first I need to know how many people might be interested...

And
what is the best option for you.

At least we can fly again in Switzerland and France... So it might
take some time for me to build a website for this product...

Luc JOB
DG-800B


I'd be interested in #3, the complete instrument, ready to plug in.

RO

  #5  
Old May 20th 20, 03:04 AM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 100
Default AOA indicator poll.

Option #3 for me
Will need instruction for installation...
Dan
  #6  
Old May 20th 20, 04:16 AM posted to rec.aviation.soaring
GliderCZ
external usenet poster
 
Posts: 28
Default AOA indicator poll.

On Tuesday, May 19, 2020 at 1:00:05 PM UTC-7, Luc Job wrote:
Hi!

I have developed last year a solid-state AOA indicator, based on a
differential pressure measurement (total pressure/pressure at angle)

Undoubtedly, this is a primary flight instrument to me:

-It shows where you are aerodynamically speaking, independently of
all the variable parameters: Load, flaps position, airbrakes...etc, and
does not need a calculation or interpretation to check if you are
flying right or not... And if the display is well done you will have a
clear indication of the ongoing tendency towards a safe or dangerous
situation.

-It give me an accurate indication to adapt the flaps position to stay
at the best glide angle through the whole speed range.

-It is a good indication of the optimal attitude during winch launch
and can prevent a high speed stall at high load factor.

Some pictures of my development are available he
https://bit.ly/aoaindicator
On the video the blinking effect is induced by the camera, the leds
simply fade in or out gradually, only the red one blinks at stall angle
or if the AOA rate of increase will induce a stall within 2 seconds...
you can see that the instrument works as good as its free
alternative...

The present system includes:

-A 5 leds indicator, red-amber-green-white-blue. The corresponding
AOA for each led is programmed in flight with a push-button.

-An audio input and output: Instead of adding a warning while flying
at higher AOA than the maximum Cz (minimum sink rate), the
instrument hashes the audio output of the vario gradually, cutting
the sound at stall. This is an excellent indication that something is
wrong without adding noise... You can continue to watch outside
while climbing at the best speed, and avoid to enter a spin in the
middle of others.

-A serial i/o for software upgrade and continuous transmission of the
data to another instrument.

-An optional light sensor to adapt the luminosity to the ambient light
level... But the indirect illumination and a better reflector (in
development) has proved that it is probably unnecessary.

The only hardware modification is the installation of an angled
pressure port at a suitable place: angle is not critical, but flow must
be as undisturbed as possible. On the DG I've put mine under the
nose, about 170 mm from the tip, where I had access to the outer
hull from the inside. I drilled a 2 mm hole and glued a small
pressure chamber inside to plug a 4 mm hose. That's all.

Power drain is lower than 20 mA @ 12V, less on ground as no led is
switched on... So no switch, but an internal polyfuse to avoid any
dangerous current drain... So it is simply added to the (fused)
instruments circuit.

Now as the system proves to be functional and efficient it's time to
do something with it.

Many options are possible:

1) I can order and sell PCB's only, with a BOM and the software...
This is obviously the cheapest way... But components are mostly
SMD... So you need an oven or a lot of patience and skill... Up to
you to make a box adapted to your needs. Price should be about $10
including shipping.

2) I can sell a complete kit with all the components, PCB, software,
connectors and box... Components are not expensive except the 2
pressure sensors ($35 each)... So I should be able to make this for
about $150...

3) If you prefer a complete instrument, ready to plug-in (except the
pressure port installation) the price should be in the 300-400$ I


Interested in Option 3.

  #7  
Old May 20th 20, 04:54 AM posted to rec.aviation.soaring
SoaringXCellence
external usenet poster
 
Posts: 385
Default AOA indicator poll.

Luc,

Have you looked at the AOA indicators that are currently used in the GA fleet (mostly experimental aircraft)? There is a "standar" (sort of) depiction of the Aoa that you might want to follow.

https://www.aircraftspruce.com/menus...ndicators.html

Most of these use similar patterns to indicate approaching the stall. The center blue dot could be the optimal glide angle for a glider. Many of these systems also have an aural component that aggressively announces "PUSH" if you don't respond to less insistent prompts.

I'm not sure we need multiple ways to demonstrate the same phenomenon.

Mike
  #8  
Old May 20th 20, 06:32 AM posted to rec.aviation.soaring
John Foster
external usenet poster
 
Posts: 354
Default AOA indicator poll.

On Tuesday, May 19, 2020 at 9:54:55 PM UTC-6, SoaringXCellence wrote:
Luc,

Have you looked at the AOA indicators that are currently used in the GA fleet (mostly experimental aircraft)? There is a "standar" (sort of) depiction of the Aoa that you might want to follow.

https://www.aircraftspruce.com/menus...ndicators.html

Most of these use similar patterns to indicate approaching the stall. The center blue dot could be the optimal glide angle for a glider. Many of these systems also have an aural component that aggressively announces "PUSH" if you don't respond to less insistent prompts.

I'm not sure we need multiple ways to demonstrate the same phenomenon.

Mike


I don't mean to be "that guy", but how is this different from a side-mounted yaw string (functionally, that is)? Some pilots mount a yaw string to the side of the canopy which has a vertical excursion, which indicates relative angle of the wind. With a stripe of electrical tape laid out on the inside of the canopy at the angle of stall, this should give you the same information at a much reduced cost, I would think.
  #9  
Old May 20th 20, 06:37 AM posted to rec.aviation.soaring
John Foster
external usenet poster
 
Posts: 354
Default AOA indicator poll.

On Tuesday, May 19, 2020 at 11:32:56 PM UTC-6, John Foster wrote:
On Tuesday, May 19, 2020 at 9:54:55 PM UTC-6, SoaringXCellence wrote:
Luc,

Have you looked at the AOA indicators that are currently used in the GA fleet (mostly experimental aircraft)? There is a "standar" (sort of) depiction of the Aoa that you might want to follow.

https://www.aircraftspruce.com/menus...ndicators.html

Most of these use similar patterns to indicate approaching the stall. The center blue dot could be the optimal glide angle for a glider. Many of these systems also have an aural component that aggressively announces "PUSH" if you don't respond to less insistent prompts.

I'm not sure we need multiple ways to demonstrate the same phenomenon.

Mike


I don't mean to be "that guy", but how is this different from a side-mounted yaw string (functionally, that is)? Some pilots mount a yaw string to the side of the canopy which has a vertical excursion, which indicates relative angle of the wind. With a stripe of electrical tape laid out on the inside of the canopy at the angle of stall, this should give you the same information at a much reduced cost, I would think.


It does seem like a pretty cool idea though, if you want to spend the money for it and not clutter the outside of your canopy with more than one string.
  #10  
Old May 20th 20, 08:41 AM posted to rec.aviation.soaring
Luc Job[_2_]
external usenet poster
 
Posts: 22
Default AOA indicator poll.

Hi John...

The side string is perfectly Ok... As long as the middle string is perfectly centered.

Even a slight slip will disturb the side strings too much to have an useable indication. And it is very unlikely that you enter a stall by chance while flying straight with a perfectly centered string.

The electronic instrument seems to be much less sensitive to that: Presently I'm using the pitot + static of the fuselage, plus the centered pressure port under the nose and it is Ok... I should check by using the antenna pressure to confirm...
 




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