A Germanwings Airbus A320-200, registration D-AIQH performing flight 4U-2181 from Amsterdam (Netherlands) to Stuttgart (Germany) with 64 passengers and 6 crew, was taxiing for departure when a light nasty odour was noticed throughout the aircraft. Following departure the odour became significantly pronounced developing as a smell of old socks, that was clearly noticeable in both flight deck and the forward area of the cabin. The flight crew donned their oxygen masks, checked with the cabin which reported more or less okay, disabled the left hand engine (CFM56) bleed air and left hand air conditioning system resulting in the smell dissipating and decided to continue to Stuttgart. Enroute with no smell detectable the flight crew removed their oxygen masks. During the descent the smell returned briefly when the crew attempted to re-engage left hand bleed air and air conditioning and dissipated after the left hand bleed air and air conditioning system were switched off again. The aircraft landed safely on Stuttgart's runway 25 about 50 minutes after departure from Amsterdam. There were no complaints about health issues from both passengers and cabin crew following the flight.
The following day a flight attendant reported health issues consistent with contaminated cabin air and went to see a doctor.
The occurrence aircraft remained on the ground for about 39 hours before resuming service.
Initial findings suggest that although the aircraft had not been de-iced in Stuttgart for the outbound flight and in Amsterdam for the occurrence flight, de-icing fluid had entered the left hand engine in larger quantities as well as the right hand engine in smaller quantities. Previous flights had been without any anomaly.
Germany's BFU reported they are aware of the occurrence and are currently collecting information to decide about the classification of the occurrence.