Whilst doing a quick search on some previous Germanwings incidents, I came across this report summary, interesting read, different airframe and I hope not a related incident but my heart did sink a little whilst reading it:
The German BFU released their preliminary report in German stating, that both flight crew became partially incapacitated within seconds following a strong burning electrical smell on base leg and during intercept of the localizer. The captain's oxygen level in his blood fell substantially below 80%, the first officer's oxygen level below 80% (normal value 95-98%). The first officer was on sick leave for 6 months following the event.
The flight had been delayed due to heavy snowfall in Cologne. The aircraft finally departed Vienna with a delay of 3 hours, the flight was uneventful until the aircraft turned onto the left base leg for Cologne's runway 14L when both flight crew smelled a strong electrical burning odour. Upon query the purser reported no smell in the cabin. The odour seemed to subside after a brief moment.
While the aircraft turned to intercept the localizer the first officer reported he felt seriously sick close to vomiting (German "kotzübel"), he smelled a strong electrical sweet odour and would don his oxygen mask. Alerted by that remark the captain noticed his legs and arms were tickling, his senses were literally vanishing and his sight abruptly reduced to a tunnel view. He too donned his oxygen mask. The first officer needed two attempts to don his oxygen masks. After both flight crew had donned their oxygen masks, the captain improved slightly, while the first officer's condition continued to deteriorate.
The captain (35, ATPL, 7,864 hours total, 3,107 on type) instructed the first officer (26, CPL, 720 hours total, 472 hours on type) to advise approach they would immediately contact tower and to declare Mayday on tower. While the first officer was communicating with tower declaring emergency and reporting strong smell in the cockpit the tower instructed an aircraft ahead of the A319 to go around, the aircraft established on the glide path, the captain, pilot flying, selected flaps 1 himself and disengaged the autopilot now flying manually. The aircraft was flying too fast (around 220 KIAS), the captain therefore deployed spoilers, instructed the first officer therefore to lower the gear and later to select flaps 2.
At that point the first officer felt overwhelmed, he could no longer overview the scenario, could no longer process the arriving information and had difficulty to focus on single aspects of the scenario. The captain felt that while manually flying the aircraft he was at the upper limit of what he was capable to do in his bad bodily shape.
After the crew managed to configure the aircraft for landing, the aircraft was still too fast, the captain decided that a go-around was not possible and thus cancelled the stability criteria (gate at 1000 feet), their only option was to put the aircraft down as quickly as possible.
The first officer described the time between 1800 feet and touchdown as an eternity, he was however able to recognize that the aircraft had reached and was maintaining correct approach speed and realized they had not worked the landing checklist. He thus processed the landing checklist which required all his efforts, it was difficult to process the checklist, it was difficult to concentrate and think.
Both pilots reported that just prior to landing they perceived their situation as surreal and like in a dream.
The aircraft touched down on the runway, the automatic brakes slowed the aircraft to about 40 knots, the captain subsequently applied manual brakes, the aircraft began to skid, the captain however managed to slow the aircraft to taxi speed and vacate the runway via taxiway A3. He then joined taxiway A and handed controls to the first officer to be able to talk to emergency services. The first officer totally focussed on steering the aircraft that he did not get anything that happened around him.
The captain in the meantime was talking to emergency services, tower did not want them taxi to the gate but to a remote stand away from the buildings, following that decision the captain took over again and taxied the aircraft to the stand. Shortly before arriving on stand the first officer noticed they had not yet run the after landing checklist, the checklist was now executed. After reaching the stand and applying park brake both crew realised the APU had not yet been started, the APU was started.
The first officer wanted to open his side window, but needed three attempts to do so. After the window was open he removed his oxygen masks, but immediately noticed the acrid smell again and donned his oxygen mask again.
Emergency services subsequently entered the cockpit, the first officer needed assistance to get off the aircraft, while the captain remained in the cockpit until all passengers had disembarked. Emergency services measured oxygen levels in the blood of both pilots and found the captain substantially below 80% (at about 70%) and the first officer below 80%, paramedics commented both pilots were close to faint.
The BFU stated the events in the cockpit remained unnoticed in the cabin until after landing.
Following landing the aircraft was checked by airline maintenance who identified de-icing fluid as source of the smell. The technicians reported that they could clearly detect the odour even 15 minutes after landing. Maintenance replaced cooling fans for cockpit instrumentation, no pollution was detected. The engines were checked, washed and ground run with no findings, the flight crew oxygen supply and masks replaced, and a 45 minutes test flight undertaken with no odours, the aircraft was thus returned to service on Dec 20th 2010.
A C-Check 13 months later also did not identify any possible causes of the smell.
The BFU reported that their initial information received from emergency services had been smoke in the cockpit, both pilots were treated in ambulances, it was suspected they were suffering from smoke poisoning. Subsequently the airline told the BFU, that there had been no smoke but only smell, maintenance had identified de-icing fluid as cause of the smell, the crew had been released from hospital, the crew did not suffer from any poisoning. Following that information the BFU decided to not open an investigation.
Only a year later the BFU received additional information which prompted the BFU to open an investigation.
The BFU reported that medical services at the airport already measured the blood oxygen levels of both pilots and found the values below and well below 80%. Both pilots were subsequently taken to a hospital for further diagnosis. During the drive to the hospital one pilot recovered to the point where he commented he could clearly think again. After two hours in the hospital both pilots were discharged without blood analysis.
The first officer went to the hospital again the following day for a detailed analysis of his health condition. A blood analysis detected two conspicuous values in the area of clinical chemistry, the first officer was not fit for duty for 6 months.
The BFU did not release any safety recommendations so far.
In a similiar event involving the very same Germanwings A319 the Irish AAIU concluded "The probable cause of the adverse symptoms reported by the aircraft crew and some passengers could not be determined", see Accident: Germanwings A319 at Dublin on May 27th 2008, pressurization problems.
Two more aircraft had similiar issues within 8 days prior to this accident, see Incident: Germanwings A319 at Cologne on Dec 11th 2010, smoke in cockpit and Incident: Germanwings A319 near Cologne on Dec 16th 2010, smell of smoke.
Full report is available on the German Federal Bureau of Aircraft Accident Investigation -
Here