As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 7936-IAD - LANDING GEAR DID NOT RETRACT FOLLOWING TAKEOFF. MAINTENANCE FOUND THE NOSE LANDING GEAR WEIGHT ON WHEELS PROXIMITY SENSOR OUT OF ADJUSTMENT. THE SENSOR WAS ADJUSTED AND SEVERAL GEAR EXTENSIONS AND RETRACTIONS WERE PERFORMED WITH NO ADDITIONAL DEFECTS NOTED. (S)