Flying in hills above 400 feet

[detectorguy]

I was out flying in the hills today, and my mavic pro was maxed out as far as alt 398 feet. My question here is while it is flying around in these hills and I get a low battery warning will it just fly around the hills or go over them ?

 

[lisadoc]

You're going to have to be a bit clearer with your question. What you're asking isn't specific enough and doesn't make complete sense.

If you're asking about a RTH initiated on the other side of a hill (why is your Mavic maxed at 398 feet?), what will it do? It depends on what your RTH altitude is set at and if your obstacle sensors are on. If your RTH height is lower than an object between you and your Mavic, it will collide with that object at your RTH height (OA sensors off). If your sensors are on, it may stop and try to go around the obstacle if it's something reasonable like a tree or other small (relatively) object. If it is something large like an entire hill or a large building, it likely won't be able to return and it will eventually land when it reaches critical battery.

 

[detectorguy]

Typo on my part
I was Pulled over on the side of this road. There was a place were people brave enough to climb the side of this rock and put their names. So I thought I would put my mavic up there to see how high they was putting their names. I maxed out at 393 feet which was not as high as the hill.
I thought at that point to follow the creek down into the field and as I did I had to move to follow it as it flew. Then came that sound of low battery so I started bringing it home. Then I wondered what if it had to go over anything on the way back would it make any adjustments if I had just pushed Return Home. That's all

 

[HWCM]

Typo on my part
I was Pulled over on the side of this road. There was a place were people brave enough to climb the side of this rock and put their names. So I thought I would put my mavic up there to see how high they was putting their names. I maxed out at 393 feet which was not as high as the hill.
I thought at that point to follow the creek down into the field and as I did I had to move to follow it as it flew. Then came that sound of low battery so I started bringing it home. Then I wondered what if it had to go over anything on the way back would it make any adjustments if I had just pushed Return Home. That's all

Why is your mavic topping out at 393 feet. It should go to 1640 feet.
If you are worried about going above 400 feet, you are allowed to go 400 feet ABOVE the highest structure, hill etc in your area.
But to answer your question. If your behind a hill and RTH is activated, the mavic flies a direct straight line back to the take off point. It will not fly around a hill. If the hill is between the mavic and the take off point, it will collide with the hill. Obstacle avoidance could prevent a collision, but the mavic will run out of battery trying to navigate around a hill using obstacle avoidance. At which point the critical battery will force land it right where it is. Whether it be on top of trees, over water or a safe place.

 

[Jim Flannery K0UNX]

This may help also. I had a situation where I needed to inspect the antennas on my Ham Radio club's repeater, on a mountain, after a windstorm. I could only get to a point that was a little over 3 miles away. That would be a return trip of over six miles. The mountain was considerably higher than my takeoff point, but I wasn't sure of how MUCH higher, so I set my RTH and MAX at 500 meters for the flight. There were no airports or helipads in the area, and rugged countryside. I had to climb 1308 feet to reach the height of the antennas, and was getting some warnings and signal dropout, so to return, I hit RTH to be safe. Since I was ALREADY at 1308 ft, the drone (original P4) returned at that altitude. I could have lowered it as it flew back, but decided to let the drone do all the planning to maximize the battery, and in case of signal loss. It worked out very well, but I was getting lots of "critical battery" warnings on it's descent. Note that the descent from 1308 ft. was AGONIZINGLY SLOW! On analyzing my choice later, I decided that my decision to not interfere with the autonomous RTH was the correct choice. There is no "glide path" to a drone, and I'd probably have burned up more battery by attempting to override the drone's decisions.

 

[Jim Flannery K0UNX]

I should have proof-read that before posting. I incorrectly said that I set the RTH to 500 meters. I did not. I set the max altitude to 500 meters, but didn't do anything with RTH. I was already ABOVE RTH, so the drone just stayed at the altitude it was at when I hit the RTH button.