What was found
DURING CLIMB, AIRCRAFT FAILED TO GROUND SHIFT AND A VIBRATION WAS FELT FROM THE NOSE WHEEL. AIRCRAFT RETURNED TO DTW AND LANDED WITHOUT INCIDENT. INSPECTED NOSE GEAR GROUND SHIFT MECHANISM. UNABLE TO FIND ANY MALFUNCTIONS IN GROUND SHIFT MECHANISM. FOUND A FLAT SPOT ON THE RIGHT NOSE TIRE WHICH CAUSED THE NOSE WHEEL VIBRATION. REPLACED THE RIGHT NOSE TIRE. OPERATIONAL CHECK GOOD.