I attempted to land a spaceplane on Duna next to my lander and accidentally hit it. I had used it to ferry my crew up from Kerbin to my Duna ship and decided to take it along as I had plenty of fuel and a spare docking port. Unfortunately I tried to land too close to the lander and misaimed. On the upside, the plane was unmanned and my crew on the ground were with the rover, so there were no fatalities. I'll have to add a rescue component to my next Duna mission.