That's is an interesting point but you could look at it from another angle. If the cliff face was at 45 degrees then you would be legal to fly 400 feet from any point off that face. So if the cliff face 45, 50, 60 ,70,80 or 90 degrees and say 1000 ft high and you were standing at the base then technically I would assume you can fly up to 400ft outwards and continue upwards from that face to 1400 ft from your standpoint.
I've experienced that first hand! I followed the contour of the mountain as I climbed it, but DJI Fly stopped me at 500m above the home point.
Read again. You really talking meters. Issue is in feet. 500m is a hard programmed limit.... ps, it can be defeated w/o software.
All height used by the drone is AGL...eg, calculated from take off point. If you need to go higher on a slope then landing in VLOS (when landed) and TO after 20 seconds or so, the drone resets and the new TO point is treated as 0’ AGL. If you do this you have to manually fly home to original (first) TO point and manually land. I used the trick to get over the top of the Santan Mtns behind my house... you get something like my vid below after editing out the landing at distance.
The very limited range of the VPS sensors should be a big clue.
I understand that the original message was in regard to the rules about flying less than 400 feet above ground. I was responding to dawgpilot who brought up the 500m hard programmed limit. I was just saying that I had hit the 500m limit in the video that I posted. I do understand that I could have defeated that limit by landing part of the way up the mountain, resetting the home point and taking off again, but that was a little on the risky side given the location and terrain.
