What was found
PIT-CLT - FLT 209 - ON TAKEOFF, RECEIVED AN L MAIN GEAR MESSAGE ON THE MULTI-FUNCTION DISPLAY UNIT. LEFT MAIN GEAR DID NOT RETRACT. RECYCLED PER QRH, ALL GEAR RETRACTED. GEAR EXTENSION UPON LANDING WAS NORMAL. MAINTENANCE FOUND GROUND MAINTENANCE TEST VALVE SAFETIED NOT FULLY OPEN. REPOSITIONED AND SAFETIED THE TEST VALVE. (M)