Tricycle gear
Overview
 
Tricycle gear describes an aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

 undercarriage
Undercarriage
The undercarriage or landing gear in aviation, is the structure that supports an aircraft on the ground and allows it to taxi, takeoff and land...

, or landing gear, arranged in a tricycle
Tricycle
A tricycle is a three-wheeled vehicle. While tricycles are often associated with the small three-wheeled vehicles used by pre-school-age children, they are also used by adults for a variety of purposes. In the United States and Canada, adult-sized tricycles are used primarily by older persons for...

 fashion. The tricycle arrangement has one wheel in the front, called the nose wheel, and two or more main wheels slightly aft of the center of gravity
Center of gravity
In physics, a center of gravity of a material body is a point that may be used for a summary description of gravitational interactions. In a uniform gravitational field, the center of mass serves as the center of gravity...

. Because of the ease of operating tricycle gear aircraft on the ground, the configuration is the most widely used on aircraft.

Several early aircraft had primitive tricycle gear, notably the Curtiss Pusher
Curtiss Model D
|-See also:-External links:...

s of the early 1910s.
Encyclopedia
Tricycle gear describes an aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

 undercarriage
Undercarriage
The undercarriage or landing gear in aviation, is the structure that supports an aircraft on the ground and allows it to taxi, takeoff and land...

, or landing gear, arranged in a tricycle
Tricycle
A tricycle is a three-wheeled vehicle. While tricycles are often associated with the small three-wheeled vehicles used by pre-school-age children, they are also used by adults for a variety of purposes. In the United States and Canada, adult-sized tricycles are used primarily by older persons for...

 fashion. The tricycle arrangement has one wheel in the front, called the nose wheel, and two or more main wheels slightly aft of the center of gravity
Center of gravity
In physics, a center of gravity of a material body is a point that may be used for a summary description of gravitational interactions. In a uniform gravitational field, the center of mass serves as the center of gravity...

. Because of the ease of operating tricycle gear aircraft on the ground, the configuration is the most widely used on aircraft.

Several early aircraft had primitive tricycle gear, notably the Curtiss Pusher
Curtiss Model D
|-See also:-External links:...

s of the early 1910s. Waldo Waterman
Waldo Waterman
thumb|200px|Waldo Waterman in 1920Waldo Dean Waterman was an inventor and aviation pioneer from San Diego, California...

's 1929 tailless
Flying wing
A flying wing is a tailless fixed-wing aircraft which has no definite fuselage, with most of the crew, payload and equipment being housed inside the main wing structure....

 Whatsit
Waterman Whatsit
The Whatsit was a swept-wing, tail-less airplane designed by Waldo Waterman between 1911 and 1932...

was one of the first to have a steerable nose wheel.

Tricycle gear is essentially the reverse of conventional landing gear
Conventional landing gear
thumb|The [[Piper PA-18|Piper Super Cub]] is a popular taildragger aircraft.thumb|right|A [[Cessna 150]] converted to taildragger configuration by installation of an after-market modification kit....

 or taildragger. Tricycle gear aircraft have the advantage that it is much more difficult 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 and the propeller
Propeller (aircraft)
Aircraft propellers or airscrews convert rotary motion from piston engines or turboprops to provide propulsive force. They may be fixed or variable pitch. Early aircraft propellers were carved by hand from solid or laminated wood with later propellers being constructed from metal...

 strikes the ground, causing damage. Tricycle gear planes are also easier to handle on the ground and reduce the possibility of a ground loop
Ground loop (aviation)
In aviation, a ground loop is a rapid rotation of a fixed-wing aircraft in the horizontal plane while on the ground. Aerodynamic forces may cause the advancing wing to rise, which may then cause the other wingtip to touch the ground...

, though they can be susceptible to wheel-barrowing
Wheel-barrowing
Wheel-barrowing is a problem that may occur when a pilot places excessive forward pressure on the elevator control of an aeroplane with a nose wheel during takeoff or landing. Forward pressure on the flight controls places an up force on the horizontal tail, thereby transferring weight from the...

. This is due to the main gear being behind the center of mass. Tricycle gear also provides an advantage in visibility to the pilot as the nose of the aircraft is level and, unlike in aircraft with conventional landing gear, does not block the view ahead. The nose wheel equipped aircraft also is easier to handle on the ground in high winds due to its wing negative angle of attack
Angle of attack
Angle of attack is a term used in fluid dynamics to describe the angle between a reference line on a lifting body and the vector representing the relative motion between the lifting body and the fluid through which it is moving...

. Student pilots are able to safely master nosewheel equipped aircraft more quickly.

In the United States, students trained on taildragger aircraft are assumed to be competent in tricycle-equipped aircraft, but students trained on tricycles must receive training in taildraggers.

Tricycle gear aircraft are easier to land
Landing
thumb|A [[Mute Swan]] alighting. Note the ruffled feathers on top of the wings indicate that the swan is flying at the [[Stall |stall]]ing speed...

 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 crosswind
Crosswind
A crosswind is any wind that has a perpendicular component to the line or direction of travel. In aviation, a crosswind is the component of wind that is blowing across the runway making landings and take-offs more difficult than if the wind were blowing straight down the runway...

s. 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 avoid the blast of hot, high-speed gases causing damage to the ground surface, in particular runway
Runway
According to ICAO a runway is a "defined rectangular area on a land aerodrome prepared for the landing and take-off of aircraft." Runways may be a man-made surface or a natural surface .- Orientation and dimensions :Runways are named by a number between 01 and 36, which is generally one tenth...

s and taxiway
Taxiway
A taxiway is a path on an airport connecting runways with ramps, hangars, terminals and other facilities. They mostly have hard surface such as asphalt or concrete, although smaller airports sometimes use gravel or grass....

s. The few exceptions have included the Yakovlev Yak-15
Yakovlev Yak-15
The Yakovlev Yak-15, NATO reporting name: Feather, USAF/DOD designation Type 2) was a first-generation Soviet turbojet fighter developed by the Yakovlev design bureau immediately after World War II. It used a reverse-engineered German Junkers Jumo 004 engine...

, the Supermarine Attacker
Supermarine Attacker
The Supermarine Attacker was a British single-seat naval jet fighter built by Supermarine for the Royal Navy's Fleet Air Arm . It was the FAA's first jet fighter.-Design and development:...

, and prototypes such as the Heinkel He 178
Heinkel He 178
|-See also:*List of firsts in aviation-Bibliography:* Warsitz, Lutz: The First Jet Pilot - The Story of German Test Pilot Erich Warsitz, Pen and Sword Books Ltd., England, 2009, ISBN 9781844158188.-External links:...

, the first four prototypes (V1 through V4) of the Messerschmitt Me 262
Messerschmitt Me 262
The Messerschmitt Me 262 Schwalbe was the world's first operational jet-powered fighter aircraft. Design work started before World War II began, but engine problems prevented the aircraft from attaining operational status with the Luftwaffe until mid-1944...

, and the Nene
Rolls-Royce Nene
|-See also:-References:NotesBibliography* Bridgman, L, Jane's fighting aircraft of World War II. Crescent. ISBN 0-517-67964-7-External links:* *...

 powered version of the Vickers VC.1 Viking
Vickers VC.1 Viking
The Vickers VC.1 Viking was a British twin-engine short-range airliner derived from the Vickers Wellington bomber and built by Vickers Armstrongs Limited at Brooklands near Weybridge in Surrey. In the aftermath of the Second World War, the Viking was an important airliner with British airlines...

.

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. The tailwheel also transmits loads to the airframe in a way that is less likely to cause airframe damage over time operating on rough fields. 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. Tail wheels are smaller and less expensive to buy and maintain and man-handling a tailwheel aircraft on the ground is easier. Most tailwheel aircraft are lower in overall height and thus may fit in lower hangar
Hangar
A hangar is a closed structure to hold aircraft or spacecraft in protective storage. Most hangars are built of metal, but other materials such as wood and concrete are also sometimes used...

s. Tailwheel aircraft are also more suitable for fitting with skis in wintertime.
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