Tricycle gear is a type of
aircraft
An aircraft is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or by using the Lift (force), dynamic lift of an airfoil, or in ...
undercarriage, or ''landing gear'', arranged in a
tricycle fashion. The tricycle arrangement has a single nose wheel in the front, and two or more main wheels slightly aft of the
center of gravity
In physics, the center of mass of a distribution of mass in space (sometimes referred to as the balance point) is the unique point where the weighted relative position of the distributed mass sums to zero. This is the point to which a force ma ...
. Tricycle gear aircraft are the easiest for takeoff, landing and taxiing, and consequently the configuration is the most widely used on aircraft.
[Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 524. Aviation Supplies & Academics, 1997. ][Aviation Publishers Co. Limited, ''From the Ground Up'', page 11 (27th revised edition) ]
History
Several early aircraft had primitive tricycle gear, notably very early
Antoinette planes and the
Curtiss Pushers of the pre-World War I
Pioneer Era of aviation.
Waldo Waterman's 1929
tailless ''
Whatsit'' was one of the first to have a steerable nose wheel.
In 1956,
Cessna
Cessna () is an American brand of general aviation aircraft owned by Textron Aviation since 2014, headquartered in Wichita, Kansas. Originally, it was a brand of the Cessna Aircraft Company, an American general aviation aircraft manufacturing ...
introduced sprung-steel tricycle landing gear on the
Cessna 172
The Cessna 172 Skyhawk is an American four-seat, single-engine, high wing, fixed-wing aircraft made by the Cessna Aircraft Company. . Their marketing department described this as "Land-O-Matic" to imply that these aircraft were much easier to land than tailwheel aircraft.
Tricycle gear and taildraggers compared
Tricycle gear is essentially the reverse of
conventional landing gear
Conventional landing gear, or tailwheel-type landing gear, is an aircraft undercarriage consisting of two main wheels forward of the center of gravity and a small wheel or skid to support the tail.Crane, Dale: ''Dictionary of Aeronautical Term ...
or ''taildragger''. On the ground, tricycle aircraft have a visibility advantage for the pilot as the nose of the aircraft is level, whereas the high nose of the taildragger can block the view ahead. Tricycle gear aircraft are much less liable to 'nose over' as can happen if a taildragger hits a bump or has the brakes heavily applied. In a nose-over, the aircraft's tail rises and the
propeller strikes the ground, causing damage. The tricycle layout reduces the possibility of a
ground loop, because the main gear lies behind the center of mass. However, tricycle aircraft can be susceptible to
wheel-barrowing. The nosewheel equipped aircraft also is easier to handle on the ground in high winds due to its wing negative
angle of attack
In fluid dynamics, angle of attack (AOA, α, or \alpha) is the angle between a reference line on a body (often the chord line of an airfoil) and the vector representing the relative motion between the body and the fluid through which it is m ...
. Student pilots are able to safely master nosewheel equipped aircraft more quickly.
Tricycle gear aircraft are easier to
land because the
attitude
Attitude may refer to:
Philosophy and psychology
* Attitude (psychology), an individual's predisposed state of mind regarding a value
* Metaphysics of presence
* Propositional attitude, a relational mental state connecting a person to a propo ...
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. Almost all jet-powered aircraft have been fitted with tricycle landing gear to prevent the blast of hot, high-speed gases from causing damage to the ground surface, in particular
runway
According to the International Civil Aviation Organization (ICAO), a runway is a "defined rectangular area on a land aerodrome prepared for the landing and takeoff of aircraft". Runways may be a man-made surface (often asphalt, concrete ...
s and
taxiways. The few exceptions have included the
Yakovlev Yak-15, the
Supermarine Attacker, and prototypes such as the
Heinkel He 178 that
pioneered jet flight, the first four prototypes (V1 through V4) of the
Messerschmitt Me 262
The Messerschmitt Me 262, nicknamed ''Schwalbe'' (German: " Swallow") in fighter versions, or ''Sturmvogel'' (German: " Storm Bird") in fighter-bomber versions, is a fighter aircraft and fighter-bomber that was designed and produced by the Ge ...
, and the
Nene powered version of the
Vickers VC.1 Viking. Outside of the United States – where the tricycle undercarriage had solidly begun to take root with its aircraft firms before that nation's World War II involvement
at the end of 1941 – the
Heinkel
Heinkel Flugzeugwerke () was a German aircraft manufacturing company founded by and named after Ernst Heinkel. It is noted for producing bomber aircraft for the Luftwaffe in World War II and for important contributions to high-speed flight, with ...
firm in World War II Germany began building airframe designs meant to use tricycle undercarriage systems from their beginnings, as early as late 1939 with the
Heinkel He 280 pioneering jet fighter demonstrator series, and the unexpectedly successful
Heinkel He 219 twin-engined night fighter of 1942 origin.
The taildragger configuration has its own advantages, and is arguably more suited to rougher landing strips. The tailwheel makes the plane sit naturally in a nose-up attitude when on the ground, which is useful for operations on unpaved gravel surfaces where debris could damage the propeller. The tailwheel also transmits loads to the airframe in a way much less likely to cause airframe damage when operating on rough fields. The small tailwheel is much lighter and much less vulnerable than a nosewheel. Also, a fixed-gear taildragger exhibits less
interference drag and
form drag in flight than a fixed-gear tricycle aircraft whose nosewheel may sit directly in the propeller's slipstream. Tailwheels are smaller and cheaper to buy and to maintain. Most tailwheel aircraft are lower in overall height and thus may fit in lower
hangar
A hangar is a building or structure designed to hold aircraft or spacecraft. Hangars are built of metal, wood, or concrete. The word ''hangar'' comes from Middle French ''hanghart'' ("enclosure near a house"), of Germanic origin, from Frankish ...
s. Tailwheel aircraft are also more suitable for fitting with
skis in wintertime.
References
{{Aircraft components
Aircraft undercarriage
Aircraft configurations