Tricycle gear

Tricycle gear describes an aircraft undercarriage, or "landing gear", arranged in a tricycle fashion. The tricycle arrangement has one gear strut in front, called the "nose wheel", and two or more main gear struts slightly aft of the center of gravity.

Several early aircraft had primitive tricycle gear, notably the Curtiss Pushers of the early 1910s. However, many sources credit Waldo Waterman with the invention of modern tricycle gear for his 1929 tailless "Whatsit".

Tricycle gear is essentially the reverse of conventional landing gear or "taildragger". Tricycle gear aircraft have the advantage that it is nearly impossible to make them 'nose over' as can happen if a taildragger hits a bump or has the brakes heavily applied. In a nose over, the airplane's tail tips up, burying the propeller in the ground and causing damage. Tricycle gear planes are also easier to handle on the ground and reduce the possibility of a ground loop. This is due to the main gear being behind the center of mass.

Tricycle gear aircraft are easier to land because the attitude required to land on the main gear is the same as that required in the flare, and they are less vulnerable to crosswinds. As a result, the majority of modern aircraft are fitted with tricycle gear. Jet aircraft are always fitted with tricycle landing gear, because the blast of hot, high-speed gases from the engine is not directed on to paved areas, such as runways and taxiways.

The taildragger configuration does have advantages. The rear wheel means the plane naturally sits in a nose-up attitude when on the ground; this is useful for operations on unpaved surfaces like gravel where debris could damage the propeller. Additionally, on the ground the wing naturally sits at a higher angle of attack, permitting a shorter takeoff roll than an equivalent tricycle design. The simpler main gear and small tailwheel result in both a lighter weight and less complexity if retractable. Likewise, a fixed-gear taildragger exhibits less interference drag and form drag in flight than a fixed-gear aircraft with tricycle gear.