Tricycle landing gear

AMooney M20Jwith a retractable tricycle landing gear

Polish3Xtrim 3X55 Trenerwith a fixed tricycle landing gear taxiing.

Tricycle gearis a type ofaircraftundercarriage, orlanding gear,arranged in atricyclefashion. The tricycle arrangement has a single nose wheel in the front, and two or more main wheels slightly aft of thecenter of gravity.Tricycle gear aircraft are the easiest for takeoff, landing and taxiing, and consequently the configuration is now the most widely used on aircraft.

History

Several early aircraft had primitive tricycle gear, notably very earlyAntoinetteplanes and theCurtiss Pushersof the pre-World War IPioneer Eraof aviation.Waldo Waterman's 1929taillessWhatsitwas one of the first to have a steerable nose wheel.

In 1956,Cessnaintroduced sprung-steel tricycle landing gear on theCessna 172.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 ofconventional landing gearortaildragger.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 thepropellerstrikes the ground, causing damage. The tricycle layout reduces the possibility of aground loop,because the main gear lies behind the center of mass. However, tricycle aircraft can be susceptible towheel-barrowing.The nosewheel equipped aircraft also is easier to handle on the ground in high winds due to its wing negativeangle of attack.Student pilots are able to safely master nosewheel equipped aircraft more quickly.

Tricycle gear aircraft are easier tolandbecause theattituderequired to land on the main gear is the same as that required in theflare,and they are less vulnerable tocrosswinds.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 particularrunwaysandtaxiways.The few exceptions have included theYakovlev Yak-15,theSupermarine Attacker,and prototypes such as theHeinkel He 178thatpioneered jet flight,the first four prototypes (V1 through V4) of theMesserschmitt Me 262,and theNenepowered version of theVickers 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 involvementat the end of 1941– theHeinkelfirm in World War II Germany began building airframe designs meant to use tricycle undercarriage systems from their beginnings, as early as late 1939 with theHeinkel He 280pioneering jet fighter demonstrator series, and the unexpectedly successfulHeinkel He 219twin-engined night fighter of 1942 origin.

ACessna 150taildragger.

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 lessinterference dragandform dragin 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 lowerhangars.Tailwheel aircraft are also more suitable for fitting withskisin wintertime.