What was found
FLIGHT CREW REPORTS: GEAR DISAGREE WARNING MESSAGE AND NOSE DOOR WARNING MESSAGE UPON GEAR RETRACTION DEPARTING DEN. NOSE GEAR DID NOT RETRACT. RETURNED TO DEN. (FLIGHT 5094) NLG WAS COVERED IN ICE DURING INCIDENT. BOTH THE NR 1 & 2 WOFFW PROXIMITY SENSORS COVERED IN ICE WHEN PLANE RETURNED TO GATE. DE-ICED NLG. TROUBLESHOT GEAR DISAGREE WARNING MESSAGE IAW FIM 32-60-07 & FIM 32-60-09. NO FAULTS DISCOVERED ON PSEU. PERFORMED MULTIPLE SWINGS OF NLG IAW AMM 32-30-00. NO DEFECTS AND NO GEAR DISAGREE WARNING MESSAGES DURING OPS CHECKS. NR 2 WOFFW PROXIMITY SENSOR HAD EXTENSIVE ICE COVERING THE COMPONENT & WAS UNABLE TO FUNCTION PROPERLY WHEN THE NLG RETRACTION ATTEMPTED AFTER TAKEOFF IS CAUSE. RETURN TO SERVICE.