What are the different landing gear configurations?

Landing gear configurations: Tricycle - Nose gear plus main gear, standard for modern aircraft, stable on ground, good visibility, allows level cabin; Taildragger/Conventional - Main gear plus tail wheel, lighter, lower drag, but ground handling challenges, visibility limited; Bicycle - Tandem centerline gear with wing outriggers, used on some military (B-52, U-2); Multi-bogie - Multiple wheels on each main gear, distributes load for heavy aircraft, enables operation on varied pavement (747 has 4-wheel bogies). Design considerations: Weight support and distribution for pavement loading (ACN/PCN), Retraction geometry and volume, Steering system (nose wheel), Braking capability, and Shock absorption for landing loads. Landing gear typically 4-5% of MTOW. Retraction complexity increases with size but reduces cruise drag.