As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAS-AIR TURNBACK- DURING FLAP RETRACTION AFTER TAKEOFF, EICAS DISPLAYED LEADING EDGE SLAT DISAGREE MESSAGE AS FLAP HANDLE WAS MOVED TO THE FLAP UP POSITION. THE AIRCRAFT RETURNED TO LAS AND MADE AN UNEVENTFUL LANDING. IN LAS MAINTENANCE TROUBLESHOT AND REPLACED THE LT AND RT INBOARD LEADING EDGE SLAT LOSS SENSING SWITCHES. SYSTEM TESTED GOOD. SWITCH P/N''S (LT) 31EN101-6, (RT) 31EN102-6.