LANDING TAXI GEAR DOWN GEAR UP 60 5 8 8 5 15 LANDING TAXI GEAR DOWN GEAR UP 60 5 8 8 5 15 Figure 11-11.  Landing gear handles and single and multiple light indictor. lines for signs of chafing and leakage at attach points. Warning  system micro switches (squat switches) are checked for  cleanliness and security of attachment. Actuating cylinders,  sprockets, universal joints, drive gears, linkages, and any  other accessible components are checked for condition and  obvious defects. The airplane structure to which the landing  gear is attached is checked for distortion, cracks, and general  condition. All bolts and rivets should be intact and secure. of mud and debris. Dirty switches and valves may cause false  safe light indications or interrupt the extension cycle before  the landing gear is completely down and locked. The wheel  wells should be clear of any obstructions, as foreign objects  may damage the gear or interfere with its operation. Bent  gear doors may be an indication of possible problems with  normal gear operation. Ensure shock struts are properly inflated and that the pistons  are clean. Check main gear and nose gear up lock and down  lock mechanisms for general condition. Power sources and  retracting mechanisms are checked for general condition,  obvious defects, and security of attachment. Check hydraulic  Normally, the landing gear is retracted after lift-off when  the airplane has reached an altitude where, in the event of an  engine failure or other emergency requiring an aborted takeoff,  11-13 Figure 11-12.  Landing gear safety switch. 28V DC Battery Safety switch Safety switch Lock release solenoid Lock-pin Landing gear selector valve Takeoff and Climb