What was found
AIRCRAFT WAS GROUNDED: ON ARRIVAL,4000' FLIGHT ATTENDANTS NOTIFIED FLIGHT DECK OF SEVERE FUMES, BURNING SMELL IN THE MIDDLE TO AFT CABIN. HAZE, NO SMOKE. BURNING EYES, DIFFICULT BREATHING, CHOKING, COUGHING. MAINTENANCE ISOLATED THE SOURCE OF THE ODOR TO THE APU AFTER FINDING EVIDENCE OF AN OIL LEAK. MAINTENNACE FOUND THE APU GENERATOR LEAKIING AND REPALCED IT . A SATISTAFCTORY LEAK / OPERATIONAL CHECK WAS ACCOMPLISHED WITH NO ODORS NOTED.