As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SDF FLT 2010 THE CREW REPORTED A LANDING GEAR AIR/GROUND FAIL MESSAGE UPON EXTENDING LANDING GEAR. MAINTENANCE INSPECTED AND REPLACED THE RIGHT GEAR NR 2 PROXIMITY SWITCH. ADJUSTED THE GAP ON THE RIGHT GEAR NR 1 PROXIMITY SWITCH AND SERVICED BOTH LEFT AND RIGHT GEARS. OPERATIONAL CHECKS WERE GOOD.