The Airbus A320-214 aircraft, with two pilots on board, was on a positioning flight to Dublin Airport (EIDW), Ireland, from Madrid-Barajas Airport (LEMD), Spain. There were no passengers or cabin crew on board. After take-off, the Commander detected what he described as a ‘slight chemical-type’ odour. The Commander stated that the odour eventually dissipated in the flight deck but was detectable in the aft galley. The Commander reported that during the subsequent descent into EIDW, when passing approximately 6,500 ft, a ‘very strong chemical odour’ was detected in the flight deck, and that due to its severity, he immediately ordered the donning of the flight crew oxygen masks. The Flight Crew donned their oxygen masks and subsequently removed them at approximately 600 ft to aid visibility and communication. The odour was reported to have diminished at that stage but that it was still noticeable. The aircraft landed normally on Runway (RWY) 28L at EIDW and taxied to its parking stand. The Flight Crew immediately attended a hospital, where physical examination, blood tests, X-rays, and ECGs were conducted. No abnormalities were detected and both crew members were discharged a number of hours later.
The Investigation determined that the probable cause of the fumes was contamination of the aircraft’s air conditioning system due to oil from an external oil leak at the Auxiliary Power Unit (APU) being ingested by the APU’s load compressor.
