Yakovlev Yak-3 propeller fighter. Its engine was mounted under the forward fuselage. Despite its unusual configuration, the Yak-15 was easy to fly. Although a fighter, it was mainly used to prepare Soviet pilots for flying more advanced jet fighters. Monowheel undercarriage A variation of the taildragger layout is the monowheel landing gear. To minimize drag, many modern gliders have a single wheel, retractable or fixed, centered under the fuselage, which is referred to as monowheel gear or monowheel landing gear. Monowheel gear is also used on some powered aircraft, where drag reduction is a priority, such as the Europa XS. Monowheel power aircraft use retractable wingtip legs (with small castor wheels attached) to prevent the wingtips from striking the ground. A monowheel aircraft may have a tailwheel (like the Europa) or a nosewheel (like the Schleicher ASK 23 glider). Training Taildragger aircraft require more training time for student pilots to master. This was a large factor in the 1950s switch by most manufacturers to nosewheel-equipped trainers, and for many years nosewheel aircraft have been more popular than taildraggers. As a result, most Private Pilot Licence (PPL) pilots now learn to fly in tricycle gear aircraft (e.g. Cessna 172 or Piper Cherokee) and only later transition to taildraggers. Techniques Landing a conventional geared aircraft can be accomplished in two ways. Normal landings are done by touching all three wheels down at the same time in a three-point landing. This method does allow the shortest landing distance but can be difficult to carry out in crosswinds, as rudder control may be reduced severely before the tailwheel can become effective. The alternative is the wheel landing. This requires the pilot to land the aircraft on the mainwheels while maintaining the tailwheel in the air with elevator to keep the angle of attack low. Once the aircraft has slowed to a speed that can ensure control will not be lost, but above the speed at which rudder effectiveness is lost, then the tailwheel is lowered to the ground. Examples Examples of tailwheel aircraft include: Airplanes de Havilland Canada DHC-2 Beaver Douglas DC-3 Maule M-7 Messerschmitt Bf 109 Piper J-3 Cub Supermarine Spitfire Helicopters Boeing AH-64 Apache - Attack helicopter Sikorsky SH-3 Sea King - Anti-submarine helicopter Modifications of tricycle gear aircraft Several aftermarket modification companies offer kits to convert many popular nose-wheel equipped aircraft to conventional landing gear. Aircraft for which kits are available