What was found
(CAN) AFTER TAKEOFF, THE COCKPIT AND CABIN FILLED WITH STRONG FUMES. CREW REQUIRED OXYGEN TO OPERATE AIRCRAFT, LANDED WITHOUT ANY FURTHER INCIDENT. AIRCRAFT WAS DE-ICED 3 TIMES PRIOR FLIGHT, AIR CONDITION PACKS WERE ON WITH APU BLEED. MAINTENANCE ACTION: WITH AIRCRAFT ENGINES ON LOW POWER, AIRCRAFT PRESSURIZED, PACKS OPERATED WITH APU PNEUMATIC SUPPLY, NIL FAULT FOUND. SUSPECT GLYCOL INGESTION FROM DE-ICING. CHANGED RECIRCULATION FILTERS DUE CONTAMINATED WITH GLYCOL.