TARS
TARS (Tilt-Adjustable Rotor System) is a concept to adjust the UAV's motor arm tilt. The adjustment gives the UAV more lateral agility to resist strong winds and, therefore, the ability to stay operational even in non-ideal conditions. The adjustment is done pre-flight, manually, which makes it a low-cost modification. It does not add any significant weight unlike e.g. servo-based adjustment systems do.
TARS CONCEPT IN REAL-WORLD TESTS:

