As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - FLT 844 - EN ROUTE ORD-HPN, SHORTLY AFTER ENGINE START FLIGHT ATTENDANT REPORTED SMOKE AND FUMES IN CABIN. RETURNED ORD GATE WITHOUT FURTHER INCIDENT. REALIGNED APU AIR INLET. RAN BOTH PACKS. NO SMOKE OR ODOR NOTED. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)