As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE LANDING GEAR WOULD NOT RETRACT AFTER TAKEOFF. WHEN RETRACTING FLAPS THE TAKEOFF WARNING HORN SOUNDED. THE AIRCRAFT WAS RETURNED TO IAH WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE AIR SAFETY SENSOR GAP OUT OF TOLERANCE. THE SENSOR WAS ADJUSTED IAW MM 32-09-01. GEAR RETRACTION OPERATION CHECKED NORMAL.