As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TUS INFLIGHT T1540/24AUG. CREW REPORTED BURNING SMELL IN CABIN AND COCKPIT AND FLIGHT ATTENDANT REPORTED LIGHT SMOKE INSIDE AFT STAIR AREA. RETURNED TO TUS AND LANDED WITHOUT INCIDENT. FOUND RT AIRCONDITIONING PACK AIR CYCLE MACHINE HAD SEIZED. REPLACED RT PACK AIR CYCLE MACHINE. SYSTEM GROUND CHECKED NORMAL OPS.