What was found
WHILE PERFORMING A MAINTENANCE TEST FLIGHT FOR REPLACEMENT OF RIGHT ENGINE, PILOT PERFORMED AN IN-FLIGHT FEATHER CHECK, PROPELLER FEATHERED NORMALLY. ONCE CHECK COMPLETED, PILOT ATTEMPTED TO UN-FEATHER ENG; AT THAT TIME, HE DISCOVERED 'PROP CONTROL' TO BE BINDING. PILOT MADE SEVERAL ATTEMPTS TO MOVE 'PROP CONTROL' OUT OF FEATHER POSITION. WOULD NOT MOVE. ACFT LANDED WITH RT ENG FEATHERED. ONCE AIRCRAFT WAS ON THE GROUND, RIGHT 'PROP CONTROL' MOVED FREELY. MX INSPECTED RIGHT PROP CONTROL, FOUND WHEN IN-FLIGHT, LOWER COWLING COULD HAVE POSSIBLY CAUSED BONDING OF CONTROL. RE-ROUTED PROP CONTROL CABLE TO AVOID POSSIBLE IN-FLIGHT BINDING. ACFT TEST FLOWN AGAIN, NO FURTHER BINDING OF 'PROP CONTROL' CABLE.