Lost controls of Mavic Air while mid air

[Kilrah]

I initially flew higher than my own position, but lowered to -3.9m when I got the 120m altitude warning. My own position was 112m.

Seems you're confused with heights as well. Figures are relative to takeoff point.

 

[JDawg]

Sorry for your loss. Hope something works out for you but the data is not promising.

 

[JoeyT]

Seems you're confused with heights as well. Figures are relative to takeoff point.

I'm just stating what my app is showing me. max takeoff altitude: 112.4m. during flight the last info (screenshot) I have is: distance: 341m. Hight: -3.9m. H.S 26.2 km/h. V.S 0.1 m/s

 

[DanMan32]

Altitude is relative to your takeoff point. If you received a warning at 120m, just drop down to say 110m. No need to go below where you are. Granted I have seen altitude drift a few feet where it might register -2 ft just before touchdown. But I'm landing at that point, not trying to fly inches off the ground.

Or are you saying you got a 120m warning at only 114m above ground? That doesn't sound right either.

 

[Awi]

I got a disconnect once also during my early days of flying MA. AC was about 20 meters right above me. It lowered itself and hovered about 2 meters above water, I was at lake side. Luckily, I tried to turn off the RC and turned it back on, and the connection was restored. Since then I researched the forum, changed to FCC mode and never had disconnect issue anymore.

 

[Meta4]

Or are you saying you got a 120m warning at only 114m above ground? That doesn't sound right either.

He was flying from a cliff top.
This flight is all at or below the homepoint.
The altitude warning must have been from a previous flight and obviously was when 120 metres above the homepoint level..

 

[DanMan32]

He made it sound like it was all on the same flight.

 

[twowingers]

Also sorry just a word of advice learn and test on open site first hope your data to Dji would replace drone [emoji85]

 

[ThePilot011]

Sorry for your loss. I hope DJI will help

 

[JoeyT]

Also sorry just a word of advice learn and test on open site first hope your data to Dji would replace drone [emoji85]

Thank you for your advice.

Although, There wasn't really much I can do. I had line of sight at all times. 341m distance. Battery full. No warning upon take off. Disconnected from the aircraft and never regained control. RTH was set, it came back by itself but chose to fly away instead of landing. That should never happen.

 

[JoeyT]

Sorry for your loss. I hope DJI will help

Thank you for your support. My case is still ongoing (2 days now). I will let you guys know as soon as I have an update.

 

[JoeyT]

Altitude is relative to your takeoff point. If you received a warning at 120m, just drop down to say 110m. No need to go below where you are. Granted I have seen altitude drift a few feet where it might register -2 ft just before touchdown. But I'm landing at that point, not trying to fly inches off the ground.

Or are you saying you got a 120m warning at only 114m above ground? That doesn't sound right either.

I was standing on a clifftop. So way above water level. halfway through the flight it said it reached maximum altitude so I dropped it to about my own level. It was flying just a little out over the water when I got that high wind warning and instantly lost connection. It returned home but never bother to actually land so it floated away from my position back to the water and eventually lowered out of sight.

 

[Meta4]

I was standing on a clifftop. So way above water level. halfway through the flight it said it reached maximum altitude so I dropped it to about my own level. It was flying just a little out over the water when I got that high wind warning and instantly lost connection. It returned home but never bother to actually land so it floated away from my position back to the water and eventually lowered out of sight.

There's some confusion here.
In the flight we have data for: DJI Flight Log Viewer - PhantomHelp.com
Your Phantom never went higher than 8 feet above the launch point.
If you were able to receive a warning of reaching your max altitude setting, you would have had a connection and we'd see this in the recorded data.
Are you mixing up two different flights?

Did you see the drone lowering into the water?
Did it descend slowly or just fall?
How far away was the Mavic when it descended to the water?

 

[RayOZ]

All we have is the OP’s recollection of what happened after flight logs ended. We know a pilot’s recollection of events like these are never accurate, especially if the pilot was in a state of panic realising they might lose an expensive drone. The drone does not choose not to land. If it has awareness to choose what to do, it’d choose to land somewhere safe.
From the time it lost connection to the time to reach above homepoint is unknown. For all we know it just ran low on battery and the wind just blew it away. Everything is just speculation.
It’s up to DJI to decide if it’s a warranty issue, though I highly doubt it.

 

[sar104]

Thank you for your comment!

I initially flew higher than my own position, but lowered to -3.9m when I got the 120m altitude warning. My own position was 112m. Wind conditions were perfect when I took off (no warnings), as the log shows, but it must've gotten more windy when I flew a little off the coast. However, I never lost sight of the drone which then indicates there should be a form of connection between AC and RC. Which still wouldn't have been the biggest issue since the drone did return on it's own to my exact location but did not manage to land and flew off again. Unfortunately that doesn't show up in the log. There wasn't much I could do after I got the high wind velocity warning since the connection dropped straight after.

Let's just hope for the best.

I think that you underestimated the variability of the wind in that location. You mentioned that wind conditions were "perfect" at takeoff, but just 40 m out the computed wind speed was 40 km/hr. You must have been in a particularly sheltered position. With no data for the return flight this is somewhat speculative, but it's likely that due to the cliff, the offshore wind speed at the cliff elevation had an unusual profile. You see similar effects on the lee side of ridges. I would guess that as it descended it encountered > 50 km/hr wind speed, and was pushed offshore.

Notice in the plot of aircraft tilt during the outbound segment at the cliff elevation that during the periods when no elevator or aileron was applied that it was at around 25° to hold position. That's right at the limit of pitch for RTH.

 

[sar104]

I was standing on a clifftop. So way above water level. halfway through the flight it said it reached maximum altitude so I dropped it to about my own level. It was flying just a little out over the water when I got that high wind warning and instantly lost connection. It returned home but never bother to actually land so it floated away from my position back to the water and eventually lowered out of sight.

You misread the message. At 1:10 it advised you that the attitude (not altitude) was too large. Your maximum flight altitude was set to 120 m, and the aircraft was at zero m (i.e. level with the takeoff point at that time). That was due to the high wind velocity - and you received a warning about that 55 seconds later.

 

[InvisibleName]

Thank you for your comment!

I initially flew higher than my own position, but lowered to -3.9m when I got the 120m altitude warning. My own position was 112m. Wind conditions were perfect when I took off (no warnings), as the log shows, but it must've gotten more windy when I flew a little off the coast. However, I never lost sight of the drone which then indicates there should be a form of connection between AC and RC. Which still wouldn't have been the biggest issue since the drone did return on it's own to my exact location but did not manage to land and flew off again. Unfortunately that doesn't show up in the log. There wasn't much I could do after I got the high wind velocity warning since the connection dropped straight after.

Let's just hope for the best.

I wouldn’t, you’ll just be even more disappointed!

 

[vanderzyde0]

I wouldn’t, you’ll just be even more disappointed!

If you fly below your artificial horizon (the cliff top in this example) you have to adjust the antenna to compensate for the drone not being overhead. The antenna are somewhat directional and that could have been the reason for loss of connection. It probably returned to your position as a RTH function but how much time elapsed between loss of signal and it appearing overhead? At that point it may have not had enough battery power to stay put in the wind and drifted out to the water and emergency landed due to critical battery. That’s my take on it.

Words of advice when you get your next drone - practice several flights in an open field in calm weather. Get the hang of drone behavior when you hit RTH and practice practice practice before doing any flying over water or at the beach because the wind behaves differently over bodies of water and at the shoreline.

Good luck sorry you lost your drone.

 

[Photo Booth]

When the FAA gets the mandatory hobbyist pilot aeronautical knowledge test up and running, I sure hope there are questions about wind velocity and how it can vary SIGNIFICANTLY at different altitudes.

I live in San Diego. Along the Torrey Pines cliffs over Black's Beach is where hang gliders take off and land. Why there? Because that's it's a windy spot that generates lots of lift.

Extreme caution needs to be exercised any time you fly above/near cliffs along the ocean.

Mark

 

[Photo Booth]

Words of advice when you get your next drone - practice several flights in an open field in calm weather. Get the hang of drone behavior when you hit RTH and practice practice practice before doing any flying over water or at the beach because the wind behaves differently over bodies of water and at the shoreline.

^^^
This!

When I got my Mavic last year, I spent several days going through 4 batteries each day just doing test flights above my own property. As I became more and more accustomed to controlling the drone, only then did I raise it to higher altitudes.

If I'm thinking about flying at any location where wind might be a factor, I always check the UAV Forecast App on my iPhone. By selecting the Wind Profile tab, the wind velocity at various altitudes can be seen:

UAV Forecast isn't perfect, and wind velocity can change very quickly without much notice at ground level, but the more information a pilot has the better.

Mark