What is wing loading and how does it affect aircraft characteristics?

Wing loading (W/S) is aircraft weight divided by wing reference area, expressed in lb/ft2 or kg/m2. Typical values: Gliders 5-10 lb/ft2, GA 15-25, Transports 100-150, Fighters 70-120. Effects: Low W/S - Lower stall speed, shorter takeoff/landing, better climb, but more drag at cruise, more gust-sensitive; High W/S - Higher cruise efficiency (less wetted area for given lift), less gust response, but longer runways, higher approach speeds. Design optimization balances: Takeoff/landing requirements (field length), Ride quality (gust response), Cruise efficiency (drag), and Structural weight (wing area affects weight). W/S sizing constrained by: Landing distance and approach speed, Takeoff second-segment climb, Cruise altitude capability, and Fuel efficiency requirements. Flaps increase effective wing area, enabling higher W/S while meeting low-speed requirements.