Mission Planner 1.3.41

APM:Copter 3.4rc5 Quad

Does anyone know if there is a way to create a mission which will switch between terrain following and relative altitude mode?  I'd like to be in terrain following mode for part of the mission while the copter climbs up and down a few minor hills.  Then, I'd like the copter to behave as if travelling between normal relative altitude waypoints and climb/descend to a specific relative altitude at the next WP.  After reaching the next relative waypoints(s) I want the copter to go back into terrain following mode. 

My intention is to climb around in the very rugged California hillsides and occasionally have to cross a 200 foot deep canyon without descending into it.

Thanks

Chuck Baker