Max Height and RTH Height?? for first timer

[SCK]

Just a “simple” question:


Is the max height (1640ft, 500M) and RTH height always relative to takeoff elevation? Example in question:

I am flying in mountains. Assume the mountain is 500m tall. I have max height of 500M and RTH at 200M.

If I take off at base of the mountain, I cant get over it because of Max height and if I loose connection and RTH initiates, it would/could have issues with RTH height depending on where on mountain. If RTH starts and it is blocked by mountain, it would go higher than the 200M RTH height but never exceed the 500M Max (so may not clear mountain)

If I take off on top the mountain, I can fly well above the top of the mountain (mtn height 500m + Max height 500m) and RTH would clear any obstacles (would be at 500M Mountain height + the 200M RTH height).


Am I following how the two heights work? If so, then in the same basic area, my actual above sea level height can vary greatly depending on the elevation the max height limit related to. If I am understanding it correctly, from a drone safety perspective, it would normally be better to fly to lower elevations (down the mountain) instead of to higher (up the mountain).

 

[okw]

Sounds like you've got it correctly. All heights in the settings are measured relative to the takeoff point.

 

[DanMan32]

RTH has obstacle avoidance and will go up to get over an obstacle, but never above the max height setting. Therefore in a mountain area, best to set Max height to 500m.
Even outside of a mountain area, you might need to climb up quickly to ditch any birds that might be chasing you.

 

[SCK]

this is why I asked. Flying from the top down feels riskier but based on above, it is the better way to go.