Aircraft Systems

allows adequate ground clearance for a larger propeller maintenance. Retractable landing gear is designed to and is more desirable for operations on unimproved fields. streamline the airplane by allowing the landing gear to [Figure 7-38] be stowed inside the structure during cruising flight. [Figure 7-39] With the CG located behind the main landing gear, directional control using this type of landing gear is more difficult while Brakes on the ground. This is the main disadvantage of the tailwheel Airplane brakes are located on the main wheels and are landing gear. For example, if the pilot allows the aircraft to applied by either a hand control or by foot pedals (toe or heel). swerve while rolling on the ground at a low speed, he or Foot pedals operate independently and allow for differential she may not have sufficient rudder control and the CG will braking. During ground operations, differential braking can attempt to get ahead of the main gear, which may cause the supplement nosewheel/tailwheel steering. airplane to ground loop. Pressurized Aircraft Diminished forward visibility when the tailwheel is on or near Aircraft are flown at high altitudes for two reasons. First, an the ground is a second disadvantage of tailwheel landing gear aircraft flown at high altitude consumes less fuel for a given airplanes. Because of these disadvantages, specific training airspeed than it does for the same speed at a lower altitude is required to operate tailwheel airplanes. because the aircraft is more efficient at a high altitude. Second, bad weather and turbulence may be avoided by flying Fixed and Retractable Landing Gear in relatively smooth air above the storms. Many modern Landing gear can also be classified as either fixed or aircraft are being designed to operate at high altitudes, retractable. Fixed landing gear always remains extended taking advantage of that environment. In order to fly at and has the advantage of simplicity combined with low higher altitudes, the aircraft must be pressurized or suitable supplemental oxygen must be provided for each occupant. It is important for pilots who fly these aircraft to be familiar with the basic operating principles. In a typical pressurization system, the cabin, flight compartment, and baggage compartments are incorporated into a sealed unit capable of containing air under a pressure higher than outside atmospheric pressure. On aircraft powered by turbine engines, bleed air from the engine compressor section is used to pressurize the cabin. Superchargers may be used on older model turbine-powered aircraft to pump air into the sealed fuselage. Piston-powered aircraft may use air supplied from each engine turbocharger through a sonic venturi (flow limiter). Air is released from the fuselage by Figure 7-38. Tailwheel landing gear. Figure 7-39. Fixed (left) and retractable (right) gear airplanes. 7-34