Does anybody else mistrust RTH?

[MavPro75]

That's not what the User Manual says. If obstacle avoidance is turned off, RTH won't turn it on, but RTH shouldn't turn it off, as far as I can tell. I haven't tested it, however.

My bad. You are correct! I was thinking "Sport" mode

 

[Wakesetter101]

Obstacle avoidance turns off when it is landing, not when returning. So if you hit RTH and it is flying against the sun, it won't get anywhere as it thinks there is an obstacle in the way. I usually just flip to sport mode at that point and fly it back. Be careful if you're flying long distances and endanger of losing signal, it won't return to you if going against the sun. I haven't tried at night, does RTH work in low light conditions or does obstacle avoidance hinder that as well?

 

[votography]

OK. I had a about 45 mins before going to work so I decided to practice my RTHs. Of the 6 tests, only 4 returned home as expected. One was a few feet off which I had to land manually. The last one was not good which I will describe later.

Ground conditions:

• Flat, grassy lawn 400 ft x 80 ft with trees around the edges
• Very light wind
• Sunny - 2:30 pm

Flight sequence:

• Battery was at 100% when started
• I was flying GPS with default mode ("Sports" mode OFF).
• Each time I made sure I had at least 16 satellites.
• Took off from a landing pad with well-marked design, went straight up to 30 ft and hovered for about 7 - 10 seconds for the MP to record landing position
• Flew away from base no more than 10 ft laterally and up to about 50 ft, and then hit RTH
• 4 landed perfectly, one was a few feet off (had to land manually as mentioned above)

OK, now, the last landing:

• Battery level was at 20% when I attempted the last RTH. I would never fly below 20% but since the MP was only a few feet from me, I decided to try RTH one last time since the previous one was not accurate.
• Within seconds - and only 2 ft to ground, battery dropped to 11%, and then the whole thing shut off. The MP went straight down to the grass. My heart dropped to the ground faster than the MP...
• Fortunately, there is no damage to MP thanks to the grass and extra leg extensions.

Battery level should not drop from 20% to 11% to zero in 2 seconds...

Since I am fairly new at this (about 6 hrs of flight time), please feel free to diagnose and provide me with guidance. I understand that RTH is used mostly in emergency situations, but I am new and would like to stay on the safe side. Any advise is greatly appreciated.

Thank you and keep on droning!

 

[davegtigard]

There is a problem with RTH. I was flying in Kauai. I launched from the top of a bluff 250 feet off of the water. I needed some footage of an area down below the bluff and filmed it with no problem. When I pushed the RTH button the mavic was about 200 yards offshore at an altitude of probably 50 feet over the water so as far as the mavic was concerned it was at an altitude of about -200 feet. Apparently the RTH doesn't know what to do about negative altitude so it went to the next choice and tried to land. I realized in time and flew back manually. I guess lesson is be careful if you are lower than your launch point when you press the RTH.

 

[Wakesetter101]

There is a problem with RTH. I was flying in Kauai. I launched from the top of a bluff 250 feet off of the water. I needed some footage of an area down below the bluff and filmed it with no problem. When I pushed the RTH button the mavic was about 200 yards offshore at an altitude of probably 50 feet over the water so as far as the mavic was concerned it was at an altitude of about -200 feet. Apparently the RTH doesn't know what to do about negative altitude so it went to the next choice and tried to land. I realized in time and flew back manually. I guess lesson is be careful if you are lower than your launch point when you press the RTH.

AH...I was wondering about that. I was thinking of flying from the lake side of a dam and flying down to the river. My concern is if I lost signal would it climb back over the dam. Thanks for the heads up, that could be disastrous.

 

[Rogue.Aircraft]

I use RTH every time I fly, multiple times a day. I'm almost always at 1000 feet and well beyond line of sight, I don't feel like flying out all the way back when the battery gets low so I hit RTH. Has never failed me. It saved my drone close to a dozen times by automatically triggering and coming back. The last time, I was flying from the top of a dam about a mile back, I lowered to the base to get a shot of the falls, and without warning lost all RC contact immediately. After a minute of my heart racing, there she comes, headed home. I have never had an issue with it doing anything but what it's supposed to.

 

[Wakesetter101]

I use RTH every time I fly, multiple times a day. I'm almost always at 1000 feet and well beyond line of sight, I don't feel like flying out all the way back when the battery gets low so I hit RTH. Has never failed me. It saved my drone close to a dozen times by automatically triggering and coming back. The last time, I was flying from the top of a dam about a mile back, I lowered to the base to get a shot of the falls, and without warning lost all RC contact immediately. After a minute of my heart racing, there she comes, headed home. I have never had an issue with it doing anything but what it's supposed to.

So it does return to altitude from negative elevation?

 

[Bernie707]

In my brief time with the mavic I haven't used RTH yet but it's nice to hear it's reliable when properly set. On my $150 Hubsan h501c I tested it on my first flight by turning off my controller as I'd seen in YouTube videos. It worked perfectly. I think I've been less motivated to try it on a $1000 drone after seeing all the failures people have posted here, but they seem to be cases where the pilot tried to reset the home point to the current location of the controller some distance from their takeoff point- something I've resolved not to do.

 

[Rogue.Aircraft]

So it does return to altitude from negative elevation?

Yes. It was reading a height of negative 100 feet or so. It ascended to the default height I set for RTH. Heres the video link. When it's at its lowest spot at the foot of the dam is where RTH engaged due to lost connection. About 25 seconds in. I was also getting multiple no fly zone warnings at the time, too close to a powerplant, and a no fly zone message.

 

[rydfree]

OK. I had a about 45 mins before going to work so I decided to practice my RTHs. Of the 6 tests, only 4 returned home as expected. One was a few feet off which I had to land manually. The last one was not good which I will describe later.

Ground conditions:

• Flat, grassy lawn 400 ft x 80 ft with trees around the edges
• Very light wind
• Sunny - 2:30 pm

Flight sequence:

• Battery was at 100% when started
• I was flying GPS with default mode ("Sports" mode OFF).
• Each time I made sure I had at least 16 satellites.
• Took off from a landing pad with well-marked design, went straight up to 30 ft and hovered for about 7 - 10 seconds for the MP to record landing position
• Flew away from base no more than 10 ft laterally and up to about 50 ft, and then hit RTH
• 4 landed perfectly, one was a few feet off (had to land manually as mentioned above)

OK, now, the last landing:

• Battery level was at 20% when I attempted the last RTH. I would never fly below 20% but since the MP was only a few feet from me, I decided to try RTH one last time since the previous one was not accurate.
• Within seconds - and only 2 ft to ground, battery dropped to 11%, and then the whole thing shut off. The MP went straight down to the grass. My heart dropped to the ground faster than the MP...
• Fortunately, there is no damage to MP thanks to the grass and extra leg extensions.

Battery level should not drop from 20% to 11% to zero in 2 seconds...

Since I am fairly new at this (about 6 hrs of flight time), please feel free to diagnose and provide me with guidance. I understand that RTH is used mostly in emergency situations, but I am new and would like to stay on the safe side. Any advise is greatly appreciated.

Thank you and keep on droning!

Read the manual . RTH doesn't work accurately if it is in close proximity to you . It will usually land close to where it is currently at .

 

[Rogue.Aircraft]

Read the manual . RTH doesn't work accurately if it is in close proximity to you . It will usually land close to where it is currently at .

It works as designed. If you are between 16 and 65 feet in distance pressing RTH will cause an immediate descent and landing. More than 65 feet and it will return to home if precision landing is enabled and you launched according to the specs required to use it. If you're at more than 65 feet distance and didn't ascend high enough at launch for precision landing, when RTH is triggered it will be accurate to a few meters from home, as it searches for terrain that resembles the launch zone.

 

[Rogue.Aircraft]

Don't be paranoid about RTH. I use it every time I fly, which is multiple times a day. It's never failed me. It probably has a better chance of getting home following the preprogrammed actions for a RTH then if you fly it manually. It shut off and dropped at 2 feet height because the cameras on the bottom thought it was already on the ground. Or maybe you had both sticks down/inward, which will kill the motors in a second or so. As far as the battery level dropping from 20 to 11%, that is not an actual representation of what is definitively left in the battery. It is a projection based on your current flight habits that determine how much longer you have till dead. Those numbers will jump around a lot. Sometimes when I'm flying with 25 minutes of flight time left, all I have to do is engage sport mode and fly top for speed for around a minute or so and my flight time will drop down to maybe 12 or 13 minutes of battery life. Then once I put it back in positioning mode and fly at a moderate speed, the remaining flight time will gradually go back up.

 

[votography]

Read the manual . RTH doesn't work accurately if it is in close proximity to you . It will usually land close to where it is currently at .

Actually, I was standing about 20 ft from the landing pad and I remained there at all 6 practice landings in order to keep data consistent. Perhaps I should repeat the practices again (at the same spot) to see if the results are different. Thank you all who responded. Happy flying!

 

[JS_2016]

I was flying my drone near a waterfall in the Multinohma Falls, Oregon area and decided to use RTH. The drone immediately descended toward the river below the waterfall. I cancelled the RTH and manually landed. I hesitate to use RTH as it is not a flawless feature.

 

[royster]

I always use RTH, when I have first timers with me, people just love watching the Mavic come home with me doing a "look ma, no hands"!
As above I do take over when she gets close to me & land manually,
RTH has never once failed me on my P3A or Mavic

 

[whiskeylover]

I was flying my drone near a waterfall in the Multinohma Falls, Oregon area and decided to use RTH. The drone immediately descended toward the river below the waterfall. I cancelled the RTH and manually landed. I hesitate to use RTH as it is not a flawless feature.

Were you less than 65 feet away from the aircraft?

 

[Arkarian]

RTH has worked very well for me. It will land right in the middle of my helipad as long as it is not too windy. Then I correct at the last minute.
I land it myself most of the time though.

RTH is evil if you don't check your settings and have the right RTH altitude or if your home point is not fixed.
Flying under trees or obstacles can be very bad if it goes into RTH mode and flys up into something. It can't see up.
Flying under bridges without the right settings can cause your drone to hit the water.

Also if you have the drone in sport mode it turns off obstacle avoidance. Be smart. Be safe.

 

[Arkarian]

Were you less than 65 feet away from the aircraft?

Yeah I learned this playing with the built in simulator before I ever flew. Telling it to RTH less than 65 feet away makes it land where it is.

 

[dewster]

I find people either always use it, or never use it.
I used it this year for yuks once.
There was no way I was trusting a computer to land my 'unobtainable' last year.

Lol. Your pretty much trusting the computer to fly. Just think about how much control you really have. I will admit that I get the shakes whenever I use an automated feature. It's just funny what we place our trust in.

 

[Rogue.Aircraft]

I was flying my drone near a waterfall in the Multinohma Falls, Oregon area and decided to use RTH. The drone immediately descended toward the river below the waterfall. I cancelled the RTH and manually landed. I hesitate to use RTH as it is not a flawless feature.

If that really happened without any user error or a critically low battery , I'd be sending mine in for repair. Only because In my experience the RTH on the Mavic DOES indeed work flawlessly.