What was found
(CAN) ON APPROACH NOSE DOOR OPEN AT 250 KTS WITH NO INPUT TO GEAR HANDLE. NOSE GEAR SOUNDED LIKE IT CYCLED AND GEAR DISAGREE MESSAGE. ABORTED APPROACH. MANUAL EXTENSION PERFORMED. EMERGENCY DECLARED AND LANDED.DUPLICATED PROBLEM IN HANGAR ON JACKS.NLG DOOR WOULD OPEN / CLOSE INTERMITTENTLY. R&R'D PSEU AND GEAR SELECTOR HANDLE AS PRECAUTIONARY. THE PARTS REMOVAL REPORT FROM THE SPARES DEPT INDICATE THAT: "FOUND LOOSE NUT IN HOUSING OF THE LANDING GEAR CONTROL ASSEMBLY".