LANDING GEAR - DESCRIPTION
1. General
A. The landing gear consists of two main gear and one nose gear. (Fig. 1) Each main gear is located aft of the rear wing spar inboard of the engine nacelles. The nose gear is located below the aft bulkhead of the control cabin.
B. The main and nose gear use air-oil type shock struts to absorb impact on landing and vibrations and shock from movement of the airplane on the ground. Each nose and main gear is equipped with two tire and wheel assemblies. Each main gear wheel is fitted with disc-type hydraulic brakes modulated by an antiskid system.
C. The main gear (Fig. 2) is hydraulically actuated to retract inboard into the fuselage. Each main gear is locked in the down position by a folding lock strut and in the up position by an uplock hook and mechanism. Shock strut doors close the opening in the wing for the main gear shock strut and drag strut. A wheel well seal closes against the main gear tire circumference when the airplane is in flight with gear retracted.
500 Landing Gear Location
Feb 15/70 Figure 1 32-00
Page 1
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
Main Gear Schematic 500
32-00Page 2 Figure 2 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. Jun 15/66
500 Nose Gear Schematic
Jun 15/66 Figure 3 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. 32-00 Page 3
D. The nose gear (Fig 3) is hydraulically actuated to retract forward into the fuselage. A lock strut assembly locks the nose gear in the up and down positions. Clamshel1-type nose gear doors close to fair with the fuselage contour when the nose gear is retracted and remain open when the nose gear is extended.
E. The main and nose gear manual extension systems are cable operated to release each gear from the up and locked position and allow the gear to free fall to the down and locked position.
F. Nose wheel steering is provided for aircraft directional control during ground maneuvers. Normal steering is accomplished by using a steering wheel located at the captain's position. A reduced range of steering by rudder pedal is available.
2. Landing Gear Air-Ground Sensing
A. Certain systems of the airplane require electrical control depending upon the condition of the airplane (airborne or on the ground) (Fig. 4). The condition of the airplane is sensed by the landing gear ground and air safety sensors (proximity switches). The safety sensors transmit signals to circuits and relays in a landing gear electrical module to provide "air" or "ground" control of the systems or components. The landing gear systems controlled by air-ground sensing are the control lever lock system and the antiskid system. Other airplane systems and components controlled by air-ground sensing are: APU fire horn system, thrust reverser, hydraulic system interconnect valve, electrical system static inverter, drain mast heater (provisions only), stall warning system, flight recorder system, air conditioning turbofans, takeoff warning system, cabin pressurization control system, voice recorder system, wing anti-ice system, electrical system, flap load limiter system, and automatic braking system. For additional information on the landing gear electrical module and the landing gear safety sensors, refer to 32-09-100 and 32-09-200.
B. An air sensing test switch and a ground sensing test switch on the electrical module are normally used to simulate airplane-in-air condition. When the airplane is operating in the ground mode, the air sensing test switch energizes the air sensing relays and the ground sensing test switch de-energizes the ground sensing relays. Both switches must be pressed and held down to simulate the airplane-in-air condition. When the switches are released, the systems return to airplane-on-ground condition. When the airplane-in-air condition is simulated, certain precautions regarding the systems listed in Fig. 5 should be observed.
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