Just bought the parrot disco, will keep my phantom 3 in addition.

[Philltayl]

yes, you are correct but when turning downwind , your airspeed will drop and you need to be aware of that and adjust attitude/power to accommodate that, in the case of our UAV's that difference in airspeed may mean the difference between fly or stall without the operator knowing what the airspeed actually is. Unless you have the telemetry that will tell you that....most speed telemetry relays on speed over the ground or GPS position speed which is not airspeed as we don't know what the wind speed is.......... just my thoughts

 

[MacCool]

And what happens when the aircraft is going downwind???????? Airflow over the wing drops to below that which is required to maintain lift............in a bad case may induce a spin.............flight controller not withstanding.........airflow always wins............

Yikes! You're a pilot?

 

[Monte55]

yes, you are correct but when turning downwind , your airspeed will drop and you need to be aware of that and adjust attitude/power to accommodate that, in the case of our UAV's that difference in airspeed may mean the difference between fly or stall without the operator knowing what the airspeed actually is. Unless you have the telemetry that will tell you that....most speed telemetry relays on speed over the ground or GPS position speed which is not airspeed as we don't know what the wind speed is.......... just my thoughts

Airplanes fly in a mass of air and this mass is generally moving. If a plane is flying at 100 mph, it doesn't make any difference which direction he is flying...the airspeed remains the same. The only thing that changes is ground speed and how the plane has to track . That's why, from the ground it looks like a plane is flying a bit sideways....but to the plane it is flying straight into a head wind. .

 

[Philltayl]

Airplanes fly in a mass of air and this mass is generally moving. If a plane is flying at 100 mph, it doesn't make any difference which direction he is flying...the airspeed remains the same. The only thing that changes is ground speed and how the plane has to track . That's why, from the ground it looks like a plane is flying a bit sideways....but to the plane it is flying straight into a head wind. .

I would love to see/analyse the telemetry of the flight before and during the 'crash' but the OP has not provided us with that opportunity so we can only 'guess' what might have happened.

 

[WilliamM]

If I remember from looking at their site the craft has a pitot tube, so it does know the air speed.

Sent from my HTC 10 using PhantomPilots mobile app

 

[Philltayl]

Thanks for that, I did not know.......do you have a link to the site please?

 

[42FrankZ]

Thanks for that, I did not know.......do you have a link to the site please?

http://bfy.tw/87vc

 

[BigAl07]

Airplanes fly in a mass of air and this mass is generally moving. If a plane is flying at 100 mph, it doesn't make any difference which direction he is flying...the airspeed remains the same. The only thing that changes is ground speed and how the plane has to track .

Monte you're incorrect. When flying it does make a WORLD of difference if you're flying against or with the wind. If you're flying along and your ground speed is 50mph but you have a tailwind of 40mph your airspeed is now roughly 10mph. If the wing needs an airspeed of 20mph to avoid a stall you have a serious problem on your hands.

The exact opposite is also true (which we try to use to our advantage). Say you're flying along and your ground speed is 50mph and you are flying directly into the wind of say 40 mph. Your "Airspeed" is now 90mph. Let's assume this particular airplane has a stall speed of 30mph. You could, in theory, land this airplane with a ground speed of 10mph (airspeed 40mph - stall speed of 30 mph = ground speed 10mph).

That mass of air is very fluid/dynamic and if you're flying close to the stall speed of the aircraft you can bet your bottom dollar you'll want to know which directly and speed the wind is traveling in. This is exactly why planes will be landing from one directly (lets say East to West) and suddenly ATC switches them West to East. This is because they want to always land INTO the wind and when the wind direction changes enough ATC will change the traffic pattern to facilitate landing with a HEAD wind and not a tail wind.

 

[Philltayl]

Monte you're incorrect. When flying it does make a WORLD of difference if you're flying against or with the wind. If you're flying along and your ground speed is 50mph but you have a tailwind of 40mph your airspeed is now roughly 10mph. If the wing needs an airspeed of 20mph to avoid a stall you have a serious problem on your hands.

The exact opposite is also true (which we try to use to our advantage). Say you're flying along and your ground speed is 50mph and you are flying directly into the wind of say 40 mph. Your "Airspeed" is now 90mph. Let's assume this particular airplane has a stall speed of 30mph. You could, in theory, land this airplane with a ground speed of 10mph (airspeed 40mph - stall speed of 30 mph = ground speed 10mph).

That mass of air is very fluid/dynamic and if you're flying close to the stall speed of the aircraft you can bet your bottom dollar you'll want to know which directly and speed the wind is traveling in. This is exactly why planes will be landing from one directly (lets say East to West) and suddenly ATC switches them West to East. This is because they want to always land INTO the wind and when the wind direction changes enough ATC will change the traffic pattern to facilitate landing with a HEAD wind and not a tail wind.

Correct BigAl07. I have personally landed a C150 at just above 2MPH ground speed. It's great fun but beware and watch your airspeed......

 

[BigAl07]

yes, you are correct but when turning downwind , your airspeed will drop and you need to be aware of that and adjust attitude/power to accommodate that, in the case of our UAV's that difference in airspeed may mean the difference between fly or stall without the operator knowing what the airspeed actually is. Unless you have the telemetry that will tell you that....most speed telemetry relays on speed over the ground or GPS position speed which is not airspeed as we don't know what the wind speed is.......... just my thoughts

One very keen thing to understand is with our R/C aircraft usually we have a very light wing loading and a fairly large performance envelope to play with. Because we don't have to design them for passenger comfort, good views from the cockpit, and they aren't stress rated they have a very light wing loading and stalls aren't usually a problem.

Some of us are also pilots and have been flying these toy place almost our whole lives. Some of the aerodynamics are important but many times our toys are not nearly as sensitive and critical as the full sized counter parts.

 

[BigAl07]

Correct BigAl07. I have personally landed a C150 at just above 2MPH ground speed. It's great fun but beware and watch your airspeed......

My very first flight lesson (Discovery Flight) was a C150, loaded, HOT day, and tall trees on the departure end of a short runway... it seemed like the plane was glued to the ground LOL... so much so I lifted my feet as we crossed the trees for some reason LOLLLLL

 

[Philltayl]

My very first flight lesson (Discovery Flight) was a C150, loaded, HOT day, and tall trees on the departure end of a short runway... it seemed like the plane was glued to the ground LOL... so much so I lifted my feet as we crossed the trees for some reason LOLLLLL

Living in the UK we don't get many hot days...............but we do have wind and 'weather'.........lol

 

[Monte55]

Monte you're incorrect. When flying it does make a WORLD of difference if you're flying against or with the wind. If you're flying along and your ground speed is 50mph but you have a tailwind of 40mph your airspeed is now roughly 10mph. If the wing needs an airspeed of 20mph to avoid a stall you have a serious problem on your hands.

The exact opposite is also true (which we try to use to our advantage). Say you're flying along and your ground speed is 50mph and you are flying directly into the wind of say 40 mph. Your "Airspeed" is now 90mph. Let's assume this particular airplane has a stall speed of 30mph. You could, in theory, land this airplane with a ground speed of 10mph (airspeed 40mph - stall speed of 30 mph = ground speed 10mph).

That mass of air is very fluid/dynamic and if you're flying close to the stall speed of the aircraft you can bet your bottom dollar you'll want to know which directly and speed the wind is traveling in. This is exactly why planes will be landing from one directly (lets say East to West) and suddenly ATC switches them West to East. This is because they want to always land INTO the wind and when the wind direction changes enough ATC will change the traffic pattern to facilitate landing with a HEAD wind and not a tail wind.

Planes fly because of airspeed over the wings...not ground speed. I could take a plane that lifts off at 40 mph let's say. BUT I have it loosely tied to the ground facing into a 50 mph head wind. i could take off and land with zero ground speed. Think of a kite. No ground speed but it flies. You need to read up a bit. Just about everything you said was wrong. I'm glad you were not my instructor when I got my pilots certificate

 

[BigAl07]

Planes fly because of airspeed over the wings...not ground speed. I could take a plane that lifts off at 40 mph let's say. BUT I have it loosely tied to the ground facing into a 50 mph head wind. i could take off and land with zero ground speed. Think of a kite. No ground speed but it flies. You need to read up a bit. Just about everything you said was wrong. I'm glad you were not my instructor when I got my pilots certificate

LOL! The kite doesn't fly from an airfoil. Talk about apples n oranges my friend.

Yea I'm sure I'm wrong since I'm current and still flying. Seriously? My point was the AIRSPEED is derived by wind direction... if you are going INTO the wind you get the benefit of the wind going over your wing faster and going WITH the wind you get less airspeed.

20 years flying manned aircraft and I'm pretty sure if I have it wrong I would have figured it out long before now.

Please tell me how what I said is wrong? The way I read it is EXACTLY what you just reiterated back.

 

[Monte55]

Correct BigAl07. I have personally landed a C150 at just above 2MPH ground speed. It's great fun but beware and watch your airspeed......

A C150 lands at about 50 mph or so depending on how its loaded and density altitude. If you landed at about 2 mph ground speed, that means you were flying in over 50 mph winds head on. Anyone that tries to take off a C150 in 50 mph is nuts. In that wind you couldn't even turn the plane on the ground. Unless the one you flew was so vastly different than the one I owned and flew for years.

 

[MacCool]

Oh my God. This is like the Twilight Zone of Aeronautics.

Ground speed has nothing to do with airflow over the wings. If your airspeed is 100 knots and you have a 50 knot headwind, your ground speed is 50 knots and the airflow over your wing is 100 knots. If you turn around 180 degrees, your ground speed will be 150 knots, and your airspeed will be 100 knots. Wind direction is irrelevant to airflow over the wings. It's only important in calculating ground speed.

Jesus you guys. You have to be kidding me. This is what comes of not teaching wind triangles anymore in ground school.

 

[Monte55]

LOL! The kite doesn't fly from an airfoil. Talk about apples n oranges my friend.

Yea I'm sure I'm wrong since I'm current and still flying. Seriously? My point was the AIRSPEED is derived by wind direction... if you are going INTO the wind you get the benefit of the wind going over your wing faster and going WITH the wind you get less airspeed.

20 years flying manned aircraft and I'm pretty sure if I have it wrong I would have figured it out long before now.

Please tell me how what I said is wrong? The way I read it is EXACTLY what you just reiterated back.

First thing..you don't have to have an airfoil shape in a wing for it to fly although it makes it more efficient. Angle of attack and power can make a disk fly. This statement is false. .....AIRSPEED is derived by wind direction... if you are going INTO the wind you get the benefit of the wind going over your wing faster and going WITH the wind you get less airspeed...

 

[Monte55]

Oh my God. This is like the Twilight Zone of Aeronautics.

Ground speed has nothing to do with airflow over the wings. If your airspeed is 100 knots and you have a 50 knot headwind, your ground speed is 50 knots and the airflow over your wing is 100 knots. If you turn around 180 degrees, your ground speed will be 150 knows and your airspeed will be 100 knots. Wind direction is irrelevant to airflow over the wings. It's only important in calculating ground speed.

Jesus you guys. You have to be kidding me. This is what comes of not teaching wind triangles anymore in ground school.

Exactly what I said earlier.

 

[MacCool]

Correct BigAl07. I have personally landed a C150 at just above 2MPH ground speed. It's great fun but beware and watch your airspeed......

And your airspeed speed was 60-70 mph (approach speed of a Cessna 150 with flaps). You're saying that you had a 58-68 mph headwind?

 

[WilliamM]

Thanks for that, I did not know.......do you have a link to the site please?

Parrot DISCO FPV