What was found
FLIGHT CREW REPORTED THAT THE LANDING GEAR WOULD NOT EXTEND AND HAD TO MANUALLY BLOW DOWN THE LANDING GEAR UPON ARRIVING INTO KABE. EFI CONTRACTED CHORD AEROSPACE CRS R58R222Y TO TROUBLESHOOT THE ISSUE. EARLY FINDINGS REPORTED WERE LANDING GEAR CONTROL CIRCUIT BREAKER WAS FOUND TO BE POPPED. AIRCRAFT WAS PLACED ON JACKS AND THE LANDING GEAR CONTROL CIRCUIT BREAKER WAS RESET, THE MAINTENANCE TEAM ALSO RESET THE DUMP VALVE, EMERGENCY EXTENSION HANDLE AND SERVICED THE GEAR BLOW DOWN BOTTLE. GEAR UP WAS SELECTED, GEAR RETRACTED WITH NO DEFECTS NOTED, GEAR DOWN WAS SELECTED AND THE LANDING GEAR CONTROL CIRCUIT BREAKER POPPED AND WOULD NOT RESET. EMERGENCY EXTENSION OF THE GEAR WAS REQUIRED. WORKING WITH GULFSTREAM TECH OPS, IT WAS RECOMMENDED TO REPLACE THE LANDING GEAR CONTROL HANDLE, HANDLE WAS REPLACED WITH NO CHANGE IN THE FAULT. AFTER FURTHER CONTINUITY CHECKS, THE DUMP VALVE SOLENOID WAS FOUND TO HAVE AN INTERNAL SHORT. REMOVED LANDING GEAR SELECTOR AND DUMP VALVE AND REPLACED WITH AN INSPECTED UNIT. PERFORMED ALL REQUIRED OPS CHECKS WITH NO FURTHER DEFECTS NOTED.