As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED THAT DURING CLIMB THE LG WOULD NOT RETRACT & A LG AIR & GND FAIL MSG APPEARED. THE CREW RETURNED TO FIELD & LANDED WITHOUT INCIDENT. MX REPLACED THE NLG AIR & GND PROXIMITY SWITCH BRACKET. OPERATIONAL CHECKS WERE GOOD WITH NO FURTHER DEFECTS NOTED.