I lost my mavic pro, help me!

[Dan C]

Just to clarify, Sport Mode simply enables a larger maximum tilt. Flying in Sport Mode is only different to flying in regular P mode if you go faster than the maximum P-mode tilt - below that the only difference is stick sensitivity. The optimal airspeed (minimizing energy per unit ground distance) is a function of wind speed but, even in still air, appears to be at least 30 mph for the Mavic series. As the headwind increases the optimal airspeed goes up, and so Sport Mode is going to be required to maximize battery use into almost any significant headwind.

I wonder what the Effective Translational Lift speed is for the Mavic Air.

That would be your most efficient speed in calm air.

 

[DagDerniT]

Are we able to adjust the angle somehow? If we could increase the tilt 10 degrees, that would increase the speed quite a bit.

 

[sar104]

I wonder what the Effective Translational Lift speed is for the Mavic Air.

That would be your most efficient speed in calm air.

In terms of flight time yes - not necessarily in terms of distance travelled.

 

[sar104]

Are we able to adjust the angle somehow? If we could increase the tilt 10 degrees, that would increase the speed quite a bit.

That's what sport mode does.

 

[DagDerniT]

Sorry, I meant increasing the angle more than what it is at in Sport mode.

 

[Gizmo6257]

Way to far away. I never go that far. I just see no reason to do that. Good luck though. I would be sick.

I lost my mavic pro.

I took it 5000 meters away and spent only 29% of the battery.
He still had 71% but on the way back the wind was against him. I couldn't reach it even forcing the stick forward a lot.

Anyway, I should have landed somewhere before zeroing the battery, but I didn't think about that at the time.

My mavic cut all connections at 0% battery.
It was 45 meters high (from the starting point), but where the last location was sent, because it is a valley, I believe it is about 60 to 80 meters high.

I've been to the location of the last location sent by mavic but found nothing.
Tthe drone disconnected 367 meters from the starting point, that is, very close to arriving.

What bothers me most is not knowing if the drone has dropped vertically straight or kept falling forward.

At the time of disconnection he was at 39km / h.

Below is the .txt file for analysis if you can help me please.

 

[Gizmo6257]

That says it all. Sounds like he panicked. Always just take your time and think about conserving battery. Sport mode is a bad mistake.

The Mavic commenced autolanding at 13:42 when the battery was showing 13% and it was still 375 feet up.
The Mavic had calculated it could not reach home and tried to land to protect itself from crashing when battery power ran out.
The OP kept driving it hard forwards as well as pushing the left stick full forward to fight the autolanding
This used up battery power needed for the autodescent from 375 feet, drained the battery quickly and it hit 5% at 14:33.6
At 15:08.3 the battery cells were all below 3.3 volts (critical low voltage), the drone was still 233 feet up and still being pushed hard with left and right sticks.
Last data record was at 15:37.1 with both sticks pushed hard forward, 147 feet up, battery reading 0% and the 3 cells showing 1.8, 2.3 and 1.5 volts.
The battery had died and the show was over.
Gravity took over from there.

 

[Gizmo6257]

Yes. Should have landed but no sport mode. At least then, it wouldn't have crashed or wouldn't have run out of battery. Never use sport mode, when worried about battery consumption. I hope you find it.

So, what one should do in this situation is look for a safe area for it to land? Would be awesome if the Mavics could recognize a safe spot for easy retrieval...

 

[Gizmo6257]

Very good advice

Avoiding this kind of situation in the first place would be a good start.
1. Fly In Line of Sight (LOS)
2. Avoid flying in high winds.
3. Make sure batteries are fully charged before flight.
4. Fly into the wind and return with the wind.
5. Be especially careful with these issues when flying over water as you will have less margin for error.
6. When caught in higher than anticipated wind, bring your drone lower to the ground/water if possible. Wind speeds are generally lower closer to the ground.
7. If not able to return to home, attempt to find a safe and flat place to land for retrieval. If flying in LOS, or shouldn’t take too long to retrieve your drone.

 

[MAvic_South_Oz]

Avoiding this kind of situation in the first place would be a good start.
1. Fly In Line of Sight (LOS)
2. Avoid flying in high winds.
3. Make sure batteries are fully charged before flight.
4. Fly into the wind and return with the wind.
5. Be especially careful with these issues when flying over water as you will have less margin for error.
6. When caught in higher than anticipated wind, bring your drone lower to the ground/water if possible. Wind speeds are generally lower closer to the ground.
7. If not able to return to home, attempt to find a safe and flat place to land for retrieval. If flying in LOS, or shouldn’t take too long to retrieve your drone.

Good list.

Can I add . . . or adjust . . . # 7 ?
7a. If flying 'long' for some reason, or wind could be an issue, pre plan at least one good landing place, a park / open area, in between home point and easy to access for recovery.

I'd go so far as visit the site, find a good spot, and place 4 large fallen branches in a square pattern on the ground to frame a landing spot.
Maybe even mark it on my map, or at least know on the map roughly how far it is from home point.

There are possibly other things you can do to increase chances of getting home.
If you turn off obstacle avoidance (flying home manually), will that give you better speed and / or reduce battery drain ?
If so, knowing how to access the menu to do this fast.

 

[Meta4]

Not if it's a stiff headwind.
Here's a thought experiment to demonstrate.
I have a Mavic Air. For simplicity, let's say it flies 30kmh in P mode, and 60kmh in sport.
...
I'll make 15kmh over the ground in P mode, versus 45kmh in sport mode. Unless sport mode consumes triple the rate of battery power, I'm winning.

The Mavic Air is a special case because it has a much lower top speed in P mode and a bigger difference between Sport Mode and P-GPS speeds.
Tilt Angle for the Air is 35° (S-mode) and 15° (P-mode) which gives speeds close to what you quoted.
But for other Mavics the Tilt Angle is 35° (S-mode) and 25° (P-mode), giving a much higher speed in P mode.

My testing with 35° (S-mode) and 25° (P-mode) shows that Sport Mode doesn't give enough extra speed to compensate for the reduced flight time.
The Air is so slow in P mode that it would be advisable to use the additional speed.
You could improve battery economy by using less than full S mode speed.

 

[Van Shteffy]

The Mavic commenced autolanding at 13:42 when the battery was showing 13% and it was still 375 feet up.
The Mavic had calculated it could not reach home and tried to land to protect itself from crashing when battery power ran out.
The OP kept driving it hard forwards as well as pushing the left stick full forward to fight the autolanding
This used up battery power needed for the autodescent from 375 feet, drained the battery quickly and it hit 5% at 14:33.6
At 15:08.3 the battery cells were all below 3.3 volts (critical low voltage), the drone was still 233 feet up and still being pushed hard with left and right sticks.
Last data record was at 15:37.1 with both sticks pushed hard forward, 147 feet up, battery reading 0% and the 3 cells showing 1.8, 2.3 and 1.5 volts.
The battery had died and the show was over.
Gravity took over from there.

I'M impressed. Great report.

 

[crayz4life]

OP, did you find your drone?

 

[tleedom]

I wonder what the Effective Translational Lift speed is for the Mavic Air.

That would be your most efficient speed in calm air.

"Effective Translational Lift" most aptly applies to helicopters and addresses the transition from hovering flight to forward flight and is not applicable to normal forward flight. The height of your hover prior to transitioning to directional flight (translational lift will happen in any direction) will be quicker as ground effect will be less at a higher altitude.

Effective translational lift - is translational lift advanced to the point where all air flowing through the rotor system of a helicopter is fresh or undisturbed air. That is air that has not already passed through the rotor system while the helicopter speed is slow or when it is in a hover.

I used a visual example of this training newly assigned pilots to our unit. When hovering over a grassy field and accelerating forward you will feel the aircraft transition at the same time aircraft passes the point where the rotor down wash no longer pushes out the grass.

 

[Dan C]

"Effective Translational Lift" most aptly applies to helicopters and addresses the transition from hovering flight to forward flight and is not applicable to normal forward flight. The height of your hover prior to transitioning to directional flight (translational lift will happen in any direction) will be quicker as ground effect will be less at a higher altitude.

Effective translational lift - is translational lift advanced to the point where all air flowing through the rotor system of a helicopter is fresh or undisturbed air. That is air that has not already passed through the rotor system while the helicopter speed is slow or when it is in a hover.

I used a visual example of this training newly assigned pilots to our unit. When hovering over a grassy field and accelerating forward you will feel the aircraft transition at the same time aircraft passes the point where the rotor down wash no longer pushes out the grass.

Ummm, this wasn't a quiz, so while your description of the phenomenon is reasonable, I'm afraid I have no prize for you. Sorry!

 

[silverdragon]

The Mavic commenced autolanding at 13:42 when the battery was showing 13% and it was still 375 feet up.
The Mavic had calculated it could not reach home and tried to land to protect itself from crashing when battery power ran out.
The OP kept driving it hard forwards as well as pushing the left stick full forward to fight the autolanding
This used up battery power needed for the autodescent from 375 feet, drained the battery quickly and it hit 5% at 14:33.6
At 15:08.3 the battery cells were all below 3.3 volts (critical low voltage), the drone was still 233 feet up and still being pushed hard with left and right sticks.
Last data record was at 15:37.1 with both sticks pushed hard forward, 147 feet up, battery reading 0% and the 3 cells showing 1.8, 2.3 and 1.5 volts.
The battery had died and the show was over.
Gravity took over from there.

(The battery had died and the show was over.
Gravity took over from there.)

Just these 2 sentence gave me the chills.... I can envision the Drone crying for help. Then a massive heart attack. Done,

 

[tleedom]

Ummm, this wasn't a quiz, so while your description of the phenomenon is reasonable, I'm afraid I have no prize for you. Sorry!

Not intended as a answer to a question, but a clarification of a aerodynamic principal routinely applied to the incorrect mode of flight.

 

[charliej]

I lost my mavic pro.

I took it 5000 meters away and spent only 29% of the battery.
He still had 71% but on the way back the wind was against him. I couldn't reach it even forcing the stick forward a lot.

Anyway, I should have landed somewhere before zeroing the battery, but I didn't think about that at the time.

My mavic cut all connections at 0% battery.
It was 45 meters high (from the starting point), but where the last location was sent, because it is a valley, I believe it is about 60 to 80 meters high.

I've been to the location of the last location sent by mavic but found nothing.
Tthe drone disconnected 367 meters from the starting point, that is, very close to arriving.

What bothers me most is not knowing if the drone has dropped vertically straight or kept falling forward.

At the time of disconnection he was at 39km / h.

Below is the .txt file for analysis if you can help me please.

Did you find it?

 

[Mavic Mac]

I use one of the common scientific data analysis applications, Wavemetrics Igor Pro. I estimated the drag coefficients by comparing freefall data with standard geometric drag models. It's highly simplified in its assumption of isotropic behavior, but it seems to be close enough to predict trajectories with a somewhat useful level of fidelity. Even with the simplest drag model included there is no analytic solution to the resulting differential equations of motion, and so those are solved with a first order numerical finite difference method. Unfortunately such methods require a reasonable level of comfort with at least college level physics and mathematics as well as somewhat costly software, and so I suspect that the audience for such a thing would be very small indeed.

Ah - would you being willing to translate this post into layman's terms ??

 

[DagDerniT]

Ah - would you being willing to translate this post into layman's terms ??

2 syllable words maximum please, lol...