As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LANDING GEAR FAILED TO RETRACT WHEN HANDLE WAS INITIALLY RAISED AFTER TAKEOFF. ALL 3 RED AND GREEN LIGHTS WERE ILLUMINATED. GEAR RETRACTED NORMALLY AFTER HANDLE WAS CYCLED PER ORH PROCEDURE. AIRCRAFT WAS GROUNDED. MAINTENANCE PERFORMED MAIN LANDING GEAR OPERATIONAL TEST IAW AMM 32-32-00-710-801, NO DEFECTS NOTED.