Smart RTH overprotective nanny....or is it.

wreckinball · Jun 18, 2018

I recently upgraded from Mavic pro to Platinum, and I keep finding myself returning to home thinking I was low on battery. This internal clock needs to be reset because the Platinum seems to fly forever. On the best day of the year here in the Pacific northwest I decided to do a distance run with my new Mavic. With no modifications to controller or drone, flying into a 5mph wind, knowing I would have the wind at my back returning, and with the Marco Polo tracker on it's back I flew to 30,000 feet out. Yes 5.7 miles away with just starting to get signal loss at 60% battery. Of course I was warned by smart RTH about not having enough battery to return, but that was with 75% left so I cancelled it. So on return I was getting about the same performance out of the battery until about 24,000 feet out, it began dropping at the rate of 3% per 1000 feet, from the 1% per 1000 feet. The range anxiety began and took hold as my wife was asking what all the beeping was for as she had never heard the low battery warning before. I launched from a lake shore which is on a 1 mile wide lake with miles and miles of cow pasture in the direction I flew. Just on the other side of the lake is a dairy I know well and with 6% remaining in the tank I looked for a safe place and as the Mavic descended into pasture I lost signal behind a row of trees. I started packing up and my wife said wheres the drone? I pointed in the general direction and went to test the Marco Polo for the first time. It took 10 minutes to drive around the lake in which I called my uncle who works at the dairy for permission to enter. With proper clearance and my tracker receiver i found my drone within 10 minutes, safe and sound video intact. The video is interesting because as the drone descended the knee high grass apparently is not suitable for landing so at several feet the drone hovered and then the video cut out and I assume the drone fell into the grass flat and made a crop circle. So the moral is the drone is smarter than even what appears to be plenty of power to return. I can only surmise that the drone takes into consideration temperature and battery performance, or lack there of. Also the field was 100 acres, I will never fly without that tracker. Although I had phone service there is no wifi or data so most other trackers would be useless. Long story but if any of the information is helpful then it is well worth it to me. Oh, for the LOS crowd I have one word "hobbyist".

Exphantomflyer · Jun 18, 2018

wreckinball said:
I recently upgraded from Mavic pro to Platinum, and I keep finding myself returning to home thinking I was low on battery. This internal clock needs to be reset because the Platinum seems to fly forever. On the best day of the year here in the Pacific northwest I decided to do a distance run with my new Mavic. With no modifications to controller or drone, flying into a 5mph wind, knowing I would have the wind at my back returning, and with the Marco Polo tracker on it's back I flew to 30,000 feet out. Yes 5.7 miles away with just starting to get signal loss at 60% battery. Of course I was warned by smart RTH about not having enough battery to return, but that was with 75% left so I cancelled it. So on return I was getting about the same performance out of the battery until about 24,000 feet out, it began dropping at the rate of 3% per 1000 feet, from the 1% per 1000 feet. The range anxiety began and took hold as my wife was asking what all the beeping was for as she had never heard the low battery warning before. I launched from a lake shore which is on a 1 mile wide lake with miles and miles of cow pasture in the direction I flew. Just on the other side of the lake is a dairy I know well and with 6% remaining in the tank I looked for a safe place and as the Mavic descended into pasture I lost signal behind a row of trees. I started packing up and my wife said wheres the drone? I pointed in the general direction and went to test the Marco Polo for the first time. It took 10 minutes to drive around the lake in which I called my uncle who works at the dairy for permission to enter. With proper clearance and my tracker receiver i found my drone within 10 minutes, safe and sound video intact. The video is interesting because as the drone descended the knee high grass apparently is not suitable for landing so at several feet the drone hovered and then the video cut out and I assume the drone fell into the grass flat and made a crop circle. So the moral is the drone is smarter than even what appears to be plenty of power to return. I can only surmise that the drone takes into consideration temperature and battery performance, or lack there of. Also the field was 100 acres, I will never fly without that tracker. Although I had phone service there is no wifi or data so most other trackers would be useless. Long story but if any of the information is helpful then it is well worth it to me. Oh, for the LOS crowd I have one word "hobbyist".

As I always say, if it’s there it’s there for a reason. I’ve seen many YouTubers ignore the LBRTH and pay the price for it.
Glad you got it back though

wreckinball · Jun 18, 2018

Exphantomflyer said:
As I always say, if it’s there it’s there for a reason. I’ve seen many YouTubers ignore the LBRTH and pay the price for it.
Glad you got it back though

Yes, you're right. I've made the same flight with original Mavic to 23,000 and returned with 16% battery, but the temp was 20°cooler.

netfolks2000 · Jun 18, 2018

So what is the actual reason that it could not come back with more battery, 60%, than what it took to get there, 40% ???? Is it temperature? He did not have a head wind. Why could it not get back with that much battery left? Why did it go down faster?

ferraript · Jun 18, 2018

netfolks2000 said:
So what is the actual reason that it could not come back with more battery, 60%, than what it took to get there, 40% ???? Is it temperature? He did not have a head wind. Why could it not get back with that much battery left? Why did it go down faster?

for example the wind might have turned the opposite way
the answer lies in his DAT log

Kilrah · Jun 18, 2018

Most likely the usual "flying into a 5mph wind" being what was on the ground and not at flying height.

netfolks2000 · Jun 18, 2018

Kilrah said:
Most likely the usual "flying into a 5mph wind" being what was on the ground and not at flying height.

Flying INTO the 5mph wind meant his having 60% battery on the way back with the wind BEHIND him was favorable. But, yes, as ferraript said, the wind direction might have changed.

Kilrah · Jun 18, 2018

What I say is that this 5mph headwind was likely what he measured at ground level, but there is no guarantee it's anywhere near that or even the same direction at the height he was flying and he probably actually had a tailwind up there without noticing it.

wreckinball · Jun 18, 2018

Yes, that is possible I use UAV forecast to have some idea of wind speed and direction at altitude. But not having the feedback that the drone is experiencing is difficult to overcome.

wreckinball · Jun 18, 2018

I plan on including my screen video when I get a chance. It starts after takeoff, but is there to the end.

netfolks2000 · Jun 18, 2018

Let's come up with a "general rule" for distance flying. How about this? Fly far only if winds are moderate, under 10 mph per the "UAV Forecast" app. Fly only up to 40% battery use, to be sure 60% is available to return. That way if winds have changed or other options are affecting, one can be more sure of being able to return all the way home. Oh, yes, and fly as low as safely possible. How does that sound? A side note here: I think cross winds are as battery-consuming as a head wind since the drone STILL has to struggle to stay on track even at 90° .

InvisibleName · Jun 18, 2018

wreckinball said:
I recently upgraded from Mavic pro to Platinum, and I keep finding myself returning to home thinking I was low on battery. This internal clock needs to be reset because the Platinum seems to fly forever. On the best day of the year here in the Pacific northwest I decided to do a distance run with my new Mavic. With no modifications to controller or drone, flying into a 5mph wind, knowing I would have the wind at my back returning, and with the Marco Polo tracker on it's back I flew to 30,000 feet out. Yes 5.7 miles away with just starting to get signal loss at 60% battery. Of course I was warned by smart RTH about not having enough battery to return, but that was with 75% left so I cancelled it. So on return I was getting about the same performance out of the battery until about 24,000 feet out, it began dropping at the rate of 3% per 1000 feet, from the 1% per 1000 feet. The range anxiety began and took hold as my wife was asking what all the beeping was for as she had never heard the low battery warning before. I launched from a lake shore which is on a 1 mile wide lake with miles and miles of cow pasture in the direction I flew. Just on the other side of the lake is a dairy I know well and with 6% remaining in the tank I looked for a safe place and as the Mavic descended into pasture I lost signal behind a row of trees. I started packing up and my wife said wheres the drone? I pointed in the general direction and went to test the Marco Polo for the first time. It took 10 minutes to drive around the lake in which I called my uncle who works at the dairy for permission to enter. With proper clearance and my tracker receiver i found my drone within 10 minutes, safe and sound video intact. The video is interesting because as the drone descended the knee high grass apparently is not suitable for landing so at several feet the drone hovered and then the video cut out and I assume the drone fell into the grass flat and made a crop circle. So the moral is the drone is smarter than even what appears to be plenty of power to return. I can only surmise that the drone takes into consideration temperature and battery performance, or lack there of. Also the field was 100 acres, I will never fly without that tracker. Although I had phone service there is no wifi or data so most other trackers would be useless. Long story but if any of the information is helpful then it is well worth it to me. Oh, for the LOS crowd I have one word "hobbyist".

Friendly piece of advice / request. Next time you post, could you break your story into some paragraphs? I really couldn’t be ar**d to try & read through all those words!

wreckinball · Jun 18, 2018

InvisibleName said:
Friendly piece of advice / request. Next time you post, could you break your story into some paragraphs? I really couldn’t be ar**d to try & read through all those words!

Ok, first post and posted from my phone. Did not realize the length. Thanks for the advice.

Prospero · Jun 18, 2018

wreckinball said:
... the drone fell into the grass flat and made a crop circle. ...".

Thereby solving one of the pervasive conspiracy theories... XD

wreckinball · Jun 19, 2018

Here is the screen recorded video.

wreckinball · Jun 19, 2018

I watched the video all the way through and noticed the airspeed actually reduced related to the wind warnings which i been accustomed to closing because they are so often. Really had little choice after making the bad choice of continuing past battery warning.

brett22 · Jun 19, 2018

wreckinball said:
I recently upgraded from Mavic pro to Platinum, and I keep finding myself returning to home thinking I was low on battery. This internal clock needs to be reset because the Platinum seems to fly forever. On the best day of the year here in the Pacific northwest I decided to do a distance run with my new Mavic. With no modifications to controller or drone, flying into a 5mph wind, knowing I would have the wind at my back returning, and with the Marco Polo tracker on it's back I flew to 30,000 feet out. Yes 5.7 miles away with just starting to get signal loss at 60% battery. Of course I was warned by smart RTH about not having enough battery to return, but that was with 75% left so I cancelled it. So on return I was getting about the same performance out of the battery until about 24,000 feet out, it began dropping at the rate of 3% per 1000 feet, from the 1% per 1000 feet. The range anxiety began and took hold as my wife was asking what all the beeping was for as she had never heard the low battery warning before. I launched from a lake shore which is on a 1 mile wide lake with miles and miles of cow pasture in the direction I flew. Just on the other side of the lake is a dairy I know well and with 6% remaining in the tank I looked for a safe place and as the Mavic descended into pasture I lost signal behind a row of trees. I started packing up and my wife said wheres the drone? I pointed in the general direction and went to test the Marco Polo for the first time. It took 10 minutes to drive around the lake in which I called my uncle who works at the dairy for permission to enter. With proper clearance and my tracker receiver i found my drone within 10 minutes, safe and sound video intact. The video is interesting because as the drone descended the knee high grass apparently is not suitable for landing so at several feet the drone hovered and then the video cut out and I assume the drone fell into the grass flat and made a crop circle. So the moral is the drone is smarter than even what appears to be plenty of power to return. I can only surmise that the drone takes into consideration temperature and battery performance, or lack there of. Also the field was 100 acres, I will never fly without that tracker. Although I had phone service there is no wifi or data so most other trackers would be useless. Long story but if any of the information is helpful then it is well worth it to me. Oh, for the LOS crowd I have one word "hobbyist".

I was away this weekend at 2 different places and now love the Smart Return Home feature. The first time I flew over a bay and did 15,500 feet each way. The SRH turned me around at 60% and came home with just enough juice to land. The second location was between mountains over water. I was going for a distance record flying in sports mode. The mavic went 19,850 feet and the SRH feature kicked in at 73%. YES 73%. I thought it a mistake but I listened and brought it back in sports mode. It did not lose connection or anything. It simply thought it needed the remaining power to get home. It got over the home position and landed with about 5% battery. I repeated the flight and the same thing happened. I was blown away and think that Smart Return Home is a must to have on. I was not going with the wind on the flight. The wind seemed to be coming from the side so I thought it was an equal scenario both ways. I would have lost it in the water as I would have gone down to 65% for sure before turning back.

wreckinball · Jun 19, 2018

brett22 said:
I was away this weekend at 2 different places and now love the Smart Return Home feature. The first time I flew over a bay and did 15,500 feet each way. The SRH turned me around at 60% and came home with just enough juice to land. The second location was between mountains over water. I was going for a distance record flying in sports mode. The mavic went 19,850 feet and the SRH feature kicked in at 73%. YES 73%. I thought it a mistake but I listened and brought it back in sports mode. It did not lose connection or anything. It simply thought it needed the remaining power to get home. It got over the home position and landed with about 5% battery. I repeated the flight and the same thing happened. I was blown away and think that Smart Return Home is a must to have on. I was not going with the wind on the flight. The wind seemed to be coming from the side so I thought it was an equal scenario both ways. I would have lost it in the water as I would have gone down to 65% for sure before turning back.

The best setting for distance I have found is obstacle avoidance off in position mode. It will be at about 30mph and use the battery most efficiently. Sport mode is fast but the RPM is out of the sweet spot for distance. Entering sport mode may be necessary on the return trip if fighting heavy winds but I have not tried that scenario yet.

wreckinball · Jun 19, 2018

Does anyone have information, whether technical or by experience, on how the smart return to home calculates when to initiate the warning?

brett22 · Jun 19, 2018

wreckinball said:
The best setting for distance I have found is obstacle avoidance off in position mode. It will be at about 30mph and use the battery most efficiently. Sport mode is fast but the RPM is out of the sweet spot for distance. Entering sport mode may be necessary on the return trip if fighting heavy winds but I have not tried that scenario yet.

I also tried the distance record under P mode and only ended up with 15,000 and change. I will try the 30 mph as you suggest. Is there an altitude that is best?