As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
JMS - ON DEPARTURE FROM JMS, THE CREW DETERMINED THE LANDING GEAR WOULD NOT RETRACT. THEY ELECTED AN AIR TURN BACK AND ACCOMPLISHED AN UNEVENTFUL LANDING. MAINTENANCE REPLACED THE LANDING GEAR CONTROL HANDLE. THE GEAR SWING AND OPS CHECK WERE SATISFACTORY.