An airplane’s landing gear includes its wheels, though they are ineffective and a “drag” after leaving the ground. That’s why some aircraft have retractable landing gears that move into the plane’s underbelly so they don’t slow down the aircraft. Sport pilots are permitted to fly fixed-gear airplanes only.
There are two landing-gear configurations. One has three wheels under the front half of the fuselage, called a tricycle gear. The other configuration has two under the front half and one near the plane’s tail, called a standard gear or a taildragger. Both are popular, though tricycle gears are more popular with those who fly into paved airfields, and taildraggers are more popular with those who land on grass or soft fields. Sport pilots are permitted to fly planes with either type of landing gear.
"Man cannot discover new oceans unless he has the courage to lose sight of the shore."
-- Andre Gide