Hi Guys, not so wise from my side, but have my lesson learned.
Yesterday managed to sink my mavic air in the sea.
Was hoping to make a range test, and flown straight into open sea area. After 3000m, 3min44sec with battery at the level of 77% turned back trying to reach home.
However drone was not able to keep speed, making only 20-25kph and after 12 minutes and 6000m was with no more power to fly and sink into the sea... approx 250m from home point.

Despite my obvious mistake of flying into the open sea, what went wrong? Why going one way 23% of battery is required and having remaining 77% doesn't enable you to come back?

Ps. After battery worning of 0% it still made like 500m.

Obvious reason: You flew into the see, with the wind behind you and when the drone went back, it had the wind infront of it not being able to reach the land with that speed.
You should've put your drone into sport mode and fly your drone back manually.

Probably wind. You flew in the same direction with the wind onto sea, which made it possible to have that speed. But to go back you will have to win it against the wind, it takes alot more for your small drone to get back.

Turning off sensors (Or just going into sport mode) could make a difference, but the battery would drain faster.

If you fly low you will also have less influence of the wind.

I was in sport mode, both ways and flying manually. Out the shore it was keeping speed of68-69kph. Was back as stated above 20-25 with sport mode.
Ps. This device is somehow recognizing wind direction and speed and calculating RTH point based on it?

You say you hit RTH but also say you flew in sport mode? Or did I missunderstood you?

Nevertheless, no, the drone does not calculate any wind. (how would it? Wind changes all the time)
But yeah, 99% sure you lost it due to the high wind. Never fly long ranges with the wind in your back.
If you do so, you risk to not be able to come back. It's better to fly against the wind and come back with the wind.

I meant decided to come back home, turned and flight manually. At certain point switched to RTH, then switched back to manual again....

Okay, thanks for clarifying. Still this won't help when you fly against high winds. Sorry about your loss though.
Lesson learned the hard way..

Exactly. As mentioned good lesson learned.
Drone was picked up by divers, cleaned it with water and packed with few kg of rise. Will see in a week time if some bites and pieces were recovered.

Kiwal Posted at 2018-8-26 23:10
I meant decided to come back home, turned and flight manually. At certain point switched to RTH, then switched back to manual again....

did you press RTH button on the remote or on screen in the app? the landing button and RTH are easily confused in the app on screen. it happens a surprising amount. even to me..

i think DJi should remove the landing button from on screen one the drone is more than 50 meters away..


edit: if it fell into salt water, count it as a total loss, salt water is extremely damaging and corrosive, and will cause irreversabl damage.   best that you contact DJi if you got refresh, they cover water damage even in this case wher eyou may have accedently caused this..  if this was fresh water, and u pulled the battery and let it dry for a long time, it maybe okay with a new battery pack, do nto reuse a water logged battery pack, salt water or fresh water!

RTH on the screen.
But my topic is not about misusing a button, but lack of power to fly.

Kiwal Posted at 2018-8-26 23:56
RTH on the screen.
But my topic is not about misusing a button, but lack of power to fly.

oh okay...  i misread original post then. sorry.  

How do you seem to not understand the basic science of flying into a head wind?

Many people just don’t understand the danger of long distance flight. Tail wind and head wind  can caused huge dangers. You need a lot more power when flying back on head wind. Many people lost their drone in this way.

Hi Kiwal,
Sorry for your loss. In my opinion it is due to heavy wind on the flight back. If you are able to upload your flight to airdata.com, you are able to view local weather conditions at time of flight.
Hope it helps to determine cause of loss. See image below.

GDL Posted at 2018-8-27 01:29
Many people just don’t understand the danger of long distance flight. Tail wind and head wind  can caused huge dangers. You need a lot more power when flying back on head wind. Many people lost their drone in this way.

yea, weaker battery drains faster as well, this is why always should take more care for the return and plan ahead

Airdata? What's thi software used for?

@chiplifter, thx for a tip. Cool app.
Now I understand better, side wind of 30km/h...
Strange one way so much impacted the other not.
As well learned that last received log speaks about battery having 6v only....hope it sink with no more power...

The direction clearly indicates that you had back wind and had to fight against the wind when coming back.

Best way to come home is put the drone in RTH and pull foward joystick. This is optimal speed/battery drain mode.

Wind.  You didn't check the wind.  

"range test"... "open sea area"... "After 3000m, 3min44sec"

I could tell this was a doomed flight right from the beginning. Sorry for the hard lesson learnt but the sea is the one place you want to be checking wind conditions prior to going out a distance where you need to return the exact same distance to reach safe ground.

Now I know a bit more...all this is new to me...

Expensive lesson.

Sorry to read that mate

Guys, ok taken my hard learning.
Now pls help me to be wiser next time. Provided similar weather conditions, 30kph tail wind, how I can estimate safe flight time and distance?

Kiwal Posted at 2018-8-27 04:13
Guys, ok taken my hard learning.
Now pls help me to be wiser next time. Provided similar weather conditions, 30kph tail wind, how I can estimate safe flight time and distance?

You can not do that precisely enough to be sure. If you need to do more long-distance flights, fly out against the wind and back with the wind. The best thing is not to fly in strong winds at all.

Its most likely because the wind but let us check about your battery also , how many times have you had charged or used this battery before ? was there any previous issue with this battery ?

Battery was "new", used 5 times, no issue before.
As well started with fully charged one.

Longer the distance higher the risk as more uncertainty and more things can go wrong. You can decide how much risk you want to take.

Kiwal Posted at 2018-8-26 23:46
Exactly. As mentioned good lesson learned.
Drone was picked up by divers, cleaned it with water and packed with few kg of rise. Will see in a week time if some bites and pieces were recovered.

You was lucky that divers were,  around hopefully you have the dji insurance and send off your drone.

The question you should ask is why take the risk fly that pfar away on open sea? By the limited flying time of drone not much thing you can do on miles away. Is that worth just be there or set a new distance record by lost your drone? By compare with the risk and what you can get from that you should be able to make a wiser decision.

I see these post so often, lets see how far away we can fly. After 3000m which is 1.86 miles were you even able to see your  Mavic Air.  The answer is no, that was your obvious error.

Kiwal Posted at 2018-8-27 04:13
Guys, ok taken my hard learning.
Now pls help me to be wiser next time. Provided similar weather conditions, 30kph tail wind, how I can estimate safe flight time and distance?

Maintain Visual Line of sight.
That DOES NOT mean that you can see your drone as a dot off in the distance

Start flight with FULL BATTERY

Be back over dry land at 50% battery.......when working hard, these batteries have been known to drop to ZERO over just a few seconds.

Randy

I sent my Mavic Air to a similar fate yesterday (8/28/18) and would like to provide some insight on "I'll never understand why new pilots..." The primary reason is because we've flown over water at similar or slightly lesser distances numerous times, in a bit of wind, and never suffered the consequences. We might get a little bit of hubris. Second, we don't account for atmospheric conditions along the entire route, and many of us are unaware of apps that help out with this. I suppose we're a little bit ignorant. Third, we fly over water because (in our thinking) it's what flying objects do: birds, helicopters, planes. Why should our drone not be able to do that? A final thought is this. Pilot follies, I believe, come down to personality. For some, there's a desire to explore and test one's limits in a given environment. For others, there's a desire to stay closer to home. Those in the former group are probably going to lose a drone no matter what.   

Hi, Sorry for the lost drone. I would recommend syncing your flight records using the DJI GO 4 app and contact our support for a fair investigation. Please see the link below. Thank you for the support.

www.dji.com/support