DARPA robotic landing gear enables Unmanned Robotic Helicopter, to land on the Rough

Despite their airborne maneuverability, helicopters, with their skid-or-wheel landing gear, still need a level surface to set down which are scarce in combat and rescue missions. Landing on an uneven surface could them to tip over or the rotor blades to come into contract with the ground resulting in disaster. And there are plenty of uneven surfaces on battlefields, ships and disaster areas.