I was proudly showing a few friends what an amazing piece of techno wizardry my XSP is and they were quite impressed - right up until the time it crashed into a tree when returning from a short waypoint mission. What has me puzzled is the RTH altitude was set to 150' and the tree it crashed into was maybe 70' tall. The aircraft should have been well above the trees as it was returning home. With a sickening crunch it hit the tree and fought to right itself while tumbling through the tree limbs. It fell to the ground and landed upside down. The camera was ripped from the gimbal and was nowhere to be found. Anyone have a guess as to why it was flying well below its assigned altitude?