Airbus A321 odor incident near Hamburg

Incident Overview and Flight Details On 2 January 2015, an Airbus A321-131 (manufacturer serial number 0518, built in 1995) operated a flight from Frankfurt Airport to Hamburg Airport. The aircraft, registered in Germany, was powered by two International Aero Engines V2530-A5 engines. The captain, a 44-year-old male with 12,330 total flight hours, was the pilot flying, while the 32-year-old co-pilot served as the pilot monitoring. The flight departed at 07:43 local time. ## Odor Report and Crew Response During the climb, the lead flight attendant reported an unpleasant odor near the doors, described as a sharp smell resembling burnt dust. The captain noted the odor as well, describing it as oil and tri-cresyl phosphate (TCP). No further odor reports were recorded on the cockpit voice recorder (CVR) until the approach to Hamburg. At 08:23:50, as the aircraft entered clouds, the captain stated the smell had returned. The co-pilot described it as resembling “cheese feet,” while the captain used the term “oil smell.” The captain shut off the number one bleed system and activated crossbleed. Approximately 30 seconds later, both pilots complained of the odor intensifying, describing it as biting. When the smell did not diminish, the bleed system was reconfigured at 08:24:50 to supply the cabin air system solely from engine number one. This configuration also failed to reduce the odor. At 08:25:16, the co-pilot suggested donning oxygen masks, which the captain confirmed. Both pilots put on their masks two seconds later. ## Approach and Landing After donning the masks, deep breathing sounds were recorded on the CVR. The pilots briefly discussed communication quality under the masks before the captain issued instructions to configure the aircraft for landing. The co-pilot informed air traffic control of the odor, the use of oxygen masks, and the resulting unusual sound, stating that no further assistance was required and that the approach was normal. At 1,000 feet above ground level, the flight data recorder (FDR) recorded a localizer deviation of 0.00039 ddm, a glideslope deviation of -0.00391 ddm, a sink rate of 720 ft/min, and a computed airspeed of 151 CAS. The landing gear was extended, and the flap lever was in the FULL position. Autothrust was in Speed-Mach mode and was deactivated at this altitude. The landing occurred at 08:31 on runway 23. The FDR recorded a touchdown speed of 131 CAS, with maximum accelerations of ny: 0.07/-0.12 g and nz: 1.29 g. ## Post-Landing and Investigation After landing, the co-pilot initially misread the apron frequency, which was corrected after air traffic control pointed out the error. The aircraft was escorted by the fire service to gate 15, where the auxiliary power unit (APU) was started. The pilots removed their oxygen masks after shutting down the engines. The captain told the fire service that the masks were put on as a precaution. The pilots stated they did not use a checklist to identify the odor source because they wanted to focus on the landing. There was no information indicating that passengers noticed the odor. ## Aircraft and Maintenance History The aircraft had a maximum takeoff mass of 83,000 kg, with a total flight time of 47,481 hours and 37,055 flights. Its airworthiness certificate was valid until 17 September 2015. The last maintenance event before the flight was a ramp inspection documented on 29 December 2014. The aircraft was last de-iced on 29 December 2014 and had completed four flights since then. The operator reported that a previous odor incident had been recorded in the aircraft’s maintenance logs on 15 September 2014.