What was found
AIRCRAFT WAS GOUNDED: DURING GEAR RETRACTION ON TAKEOFF, LANDING GEAR UNLOCK ECAM ILLUMINATED FOR ONE MINUTE. MAINTENANCE FOUND NOSE LANDING GEAR PROXIMITY SENSORS 18GA , 19GA, 24GA, AND 25GA LOOSE. SECURED PROXIMITY SENSORS IAW AMM 32-31-73 AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK.