Rotary-wing aircraft, commonly known as helicopters, are types of aircraft that use rotating blades to generate lift and thrust. Unlike fixed-wing aircraft, which rely on wings for lift, rotary-wing aircraft can take off and land vertically, hover in place, and maneuver in tight spaces. This makes them particularly useful for tasks such as search and rescue, medical transport, and aerial surveillance. The main components of a rotary-wing aircraft include the main rotor, which provides lift, and the tail rotor, which helps control the aircraft's direction. These aircraft can vary in size and design, ranging from small, single-engine helicopters to larger, multi-engine models used by military forces and for commercial purposes.