Total pilot error - I let my H hit the edge of a house. Shattered 1 blade, half of another. I was amazed that the copter continued to fly! The motors where racing and the stability was off a little. But I was able to move it out to an open area in the yard and land quickly. The motor with the missing prop was extremely hot. I replaced the two blades, recalibrated everything and was back in the air, good as new! For what it's worth, I also have two DJI copters; I don't have to describe what happens when you lose a prop on a quad. Very please with the H.