As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - FLT 1836 - EN ROUTE TUS-ORD, SHORTLY AFTER TAKEOFF, DETECTED LIGHT HAZE AND SMELL IN CABIN. BOTH PACKS TAKEN OT OF FULL COLD. SMELL AND HAZE DISSIPATED AND DID NOT RETURN FOR THE REMAINDER OF THE FLIGHT. LANDED ORD WITHOUT FURTHER INCIDENT. REPLACED APU. NO LEAKS NOTED. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)