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.