An unmanned aerial vehicle, or UAV, flies without a human pilot on board. It is controlled remotely or autonomously. The term covers everything from toy quadcopters to military Predators to fixed-wing survey aircraft. The general public calls them drones.

UAVs range in size from a few grams to several tons. Small electric quadcopters dominate consumer and commercial use. Large fixed-wing UAVs fly long missions for military and scientific purposes. Hybrid VTOL designs take off vertically and transition to forward flight. Each design trades off range, speed, payload, and endurance.

UAV applications

• Aerial photography and videography.
• Surveying and mapping.
• Infrastructure inspection.
• Agriculture: spraying and crop monitoring.
• Search and rescue, delivery, and defense.

The technology is mature, but the rules are not. Aviation authorities require registration, remote identification, and altitude limits. Operators must keep the aircraft in sight in most jurisdictions. Beyond-visual-line-of-sight operations require waivers. Privacy concerns are significant. A UAV can hover outside a window or follow a person. Law enforcement uses UAVs for surveillance. The same capability that inspects a bridge can also spy on a neighbor. UAVs are transforming industries that depend on aerial data. They are also raising questions that society has not fully answered. The technology will keep advancing. The regulations will keep catching up.