P3a speed increase

[John Locke]

Take it up 200 feet, then do csc. I bet it falls down faster than 43mph. [emoji1]

I thought we were talking about how fast we can fly. Not fall. Apples and Oranges..... Highjack!

Who's brave enough to start a thread titled "How fast can you fall? And prove it!"

I wonder if the vertical speedometer works in a fall after CSC? And no, I'm not willing to find out.

 

[Wyattroa]

Speaking of tail wind...
View attachment 56629

What app is that?

 

[flyNfrank]

the reason why the Phantom 4 can fly fast in sport mode is because you have a 45 degree angle of attack, that is just not possible on the P3. If you were able to "Hack" the P3A to fly at 45 degrees, you would surely lose altitude as you flew forward.

How do you know it would lose altitude at a 45 degree Flight Pitch?

 

[Sinisalo]

How do you know it would lose altitude at a 45 degree Flight Pitch?

If DJI thought it was possible for a Phantom 3 to fly at a 45 degree angle of attack, then the Phantom 3 would fly at a 45 degree angle of attack. The reality is the Phantom 3 lipo is just does not create enough lift to prevent losing altitude while flying with a 45 degree angle of attack. Also the Phantom 4 is more aerodynamic than the Phantom 3. The Phantom 4 can fly with a 45 degree angle of attack, the Phantom 3 cannot.

"The induced power is the required power input to create the induced velocity. As a rotorcraft undergoes translational motion, or changes angle of attack, the induced power requirement of a rotorcraft changes. Note that v∞ is the total free stream speed, including translational velocity and ambient wind velocity. To derive the effect of free stream velocity on induced power, from conservation of momentum, the induced velocity, vi for an ideal vehicle can be found by solving4....."

Read all about quadrotor dynamics here: http://ai.stanford.edu/~gabeh/papers/Quadrotor_Dynamics_GNC07.pdf

 

[DennyBoBenny]

What app is that?

It's the flight log viewer in the Go app. Click on the icon in the top left corner of the main screen.

 

[DennyBoBenny]

Hope that was a coming back speed - else you might not make it back.

I wasn't very far away from the home point...was just flying around when I noticed I was going faster than normal so I decided to see how fast I could go.

 

[DennyBoBenny]

The P3 line was obviously not designed to go more than about 35 mph. I wonder if there is a danger of the aircraft failing due to flying at speeds 60-70 mph with a tailwind.

 

[Dounin Front]

The P3 line was obviously not designed to go more than about 35 mph. I wonder if there is a danger of the aircraft failing due to flying at speeds 60-70 mph with a tailwind.

If you were just riding an air current, there would be no additional stress.
Like riding in a car, except the car is the wind (there must be a better example).

 

[flyNfrank]

I do more tailwind flying then any other. So far I have been 67mph. It's going to take a tailwind of 25mph or more for me to get above the 67mph mark. However, each time this year we have had wind gust at least 25mph and above I seem to somehow talk myself out of going to fly. If each wind gust were the same speed then I could probably work myself up to improve on the 67mph mark. But the 25mph days also include more gust that are above 30mph and when you hear those winds slamming into the side of your house it doesn't take much to my mind.

 

[Dounin Front]

I do more tailwind flying then any other. So far I have been 67mph. It's going to take a tailwind of 25mph or more for me to get above the 67mph mark. However, each time this year we have had wind gust at least 25mph and above I seem to somehow talk myself out of going to fly. If each wind gust were the same speed then I could probably work myself up to improve on the 67mph mark. But the 25mph days also include more gust that are above 30mph and when you hear those winds slamming into the side of your house it doesn't take much to my mind.

With that much wind I'll bet it makes it pretty hard to touch down, or even hand catch. Plus the P3 might want to throttle back due to battery drain in the headwinds. I've seen mine do that a couple of times.

 

[Arcticzr]

My p3p would hit 42/43 without tailwind with CF props but I've learned the hard way that CF props aren't worth it as I had a "quality" drone world prop shred just after takeoff and causing major damage as it rainbow'd to the ground


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[Meta4]

The P3 line was obviously not designed to go more than about 35 mph. I wonder if there is a danger of the aircraft failing due to flying at speeds 60-70 mph with a tailwind.

When the Phantom is riding a tailwind, it's like you walking on a moving walkway at the airport.
Your body thinks you are only doing 3 mph but the surface you walk on is moving at 5 mph itself.
You are traveling through the airport at 8 mph but only exerting the same effort and subject to the same stresses as when you walk at 3 mph.
The Phantom is only hitching a ride on a moving air current.

 

[Dounin Front]

When the Phantom is riding a tailwind, it's like you walking on a moving walkway at the airport.
Your body thinks you are only doing 3 mph but the surface you walk on is moving at 5 mph itself.
You are traveling through the airport at 8 mph but only exerting the same effort and subject to the same stresses as when you walk at 3 mph.
The Phantom is only hitching a ride on a moving air current.

I knew there was a much better definition than mine. Thanks
That's why they call you Metaphor (actually a simile, in this case)

 

[m0j0]

The P3 line was obviously not designed to go more than about 35 mph. I wonder if there is a danger of the aircraft failing due to flying at speeds 60-70 mph with a tailwind.

I would have to say no. The speed of the phantom through the air is not changed . Similar to rowing a boat down stream versus. To make it even more clear sitting in a stream with a 15 mph current your speed relegate to the water is 0 but you are still moving at 15 mph.


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[Wyattroa]

It's the flight log viewer in the Go app. Click on the icon in the top left corner of the main screen.View attachment 56686

thank you.. i fail..lol

 

[flyNfrank]

With that much wind I'll bet it makes it pretty hard to touch down, or even hand catch. Plus the P3 might want to throttle back due to battery drain in the headwinds. I've seen mine do that a couple of times.

In my case it's not too difficult to land. I'm based on wind gust and not sustained winds. There is a struggle on return flights if the head wind gust come into play. I'm finally finishing up on a video of one of my more recent flights now as I type this. The video is being put together for more then just to show head wind struggles. I'll post a new thread on it was totally completed with youtube upload.

 

[DennyBoBenny]

When the Phantom is riding a tailwind, it's like you walking on a moving walkway at the airport.
Your body thinks you are only doing 3 mph but the surface you walk on is moving at 5 mph itself.
You are traveling through the airport at 8 mph but only exerting the same effort and subject to the same stresses as when you walk at 3 mph.
The Phantom is only hitching a ride on a moving air current.

That makes sense. I was kind of thinking along those lines...it's only going to put out so much power whether it's with the wind or against it. But, I was also thinking that if you're driving and hold your hand out the window, there's a lot more wind resistance at 60 mph than 35. That's why I was wondering if there would be more wind resistance and therefore, more stress on the structure of the aircraft. Perhaps there's less stress with a tailwind, and more stress with a headwind? Anybody have a wind tunnel?

 

[Meta4]

That makes sense. I was kind of thinking along those lines...it's only going to put out so much power whether it's with the wind or against it. But, I was also thinking that if you're driving and hold your hand out the window, there's a lot more wind resistance at 60 mph than 35. That's why I was wondering if there would be more wind resistance and therefore, more stress on the structure of the aircraft. Perhaps there's less stress with a tailwind, and more stress with a headwind? Anybody have a wind tunnel?

When you are driving at 60 mph and the air is moving at zero or only a small amount, the speed difference is 60 mph.
Put your hand out and you are getting a blast of 60 mph air
Shrink down and fly in your Phantom at 35 mph in still air and it's the same .. put your hand out and the air is hitting you at 35 mph (not counting the downdraft)
If the Phantom is in a 20 mph airstream and powering just as fast as above, it's now making 55 mph over the ground but if you put your tiny hand out you are only getting a 35 mph blast.

I like the rowing with and against the current as the best analogy.

 

[Jesse James]

Nos


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[mikesmiley]

It's not about 'juice'.

You must understand the complexity of balancing forward speed with maintaining adequate thrust for lift while dealing with drag and other losses as Sinisalo has touched on.

Yeah, I understand what keeps a quad in the air, what causes it to move forward, and the forces that work against it while it does both. And if we're talking about maximum forward speed, it very much does come down to 'juice'. The ability provide the needed amperage to the motors at whatever given voltage.

I've read that the P3A/P is physically capable (battery, motors, ESCs) of flying much faster than is allowed by firmware in Atti, and that this was discovered due to a few firmware/DJI Pilot glitches in early versions.

I'll look for it when I have more time. It was here or on the DJI forum. I think here.