What was found
ON LOWERING LANDING GEAR. CIRCUIT BREAKER TRIPPED. LANDING GEAR HAD TO BE MANUALLY LOWERED FOR LANDING. ACFT LANDED WITHOUT INCIDENT. FOUND SAFETY WIRE PIGTAIL, WHICH SAFETIED THE LT UP-LATCH SWITCH, HAD CHAFED INTO AN ADJACENT WIRE BUNDLE, SHORTING OUT THE GEAR CONTROL POWER WIRE.