Air mystery: Passengers fell asleep during flight

AN airline pilot was forced to declare an emergency after almost all the passengers fell asleep during its ascent just minutes after taking off from Dublin Airport.

A report by the Department of Transport’s Air Accident Investigation Unit has revealed the potentially dangerous situation on board the Airbus A319 aircraft as it climbed towards cruising altitude just 12 minutes after leaving Dublin.

The pilot also admitted feeling “somewhat unwell” after being alerted that most of the passengers appeared to have fallen asleep.

The incident occurred on a flight operated by the German budget airline, Germanwings, between Dublin and Cologne on May 27, 2008.

The aircraft had 119 passengers, including two children and six crew on board.

However, the AAIU said it had been unable to determine the probable cause of the event.

The report documents how a cabin crew member contacted the pilot over the plane’s intercom after noticing that almost all the passengers had fallen asleep shortly after take-off. She also reported that one of her colleagues had appeared unresponsive as the flight passed 10,000ft. The cabin crew member also recalled a similar pressurisation event on a similar aircraft a few weeks earlier.

The pilot reported that he felt a tingling sensation in his right arm which was comparable with his arm “falling asleep”.

Although the pilot and crew were concerned that there was a pressurisation problem in the cabin, a check on the flight instruments showed no warning or failure signs.

However, a decision was taken to don oxygen masks, declare an emergency and return to Dublin Airport.

All symptoms disappeared after the cockpit crew donned their oxygen masks. However, no public address announcement was made to the passengers at this time and they were not informed about returning to Dublin until minutes before they landed.

The AAIU said it was understandable and even appropriate in the circumstances that no announcement was made as the cockpit crew were wearing oxygen masks.

The aircraft arrived safely back at Dublin about 14 minutes after the emergency was declared without further incident. No passengers or crew required medical assistance.

Passengers subsequently told AAIU investigators that the first indication they had of anything unusual was when they noticed the aircraft was descending. The AAIU investigator noted that the aircraft had already flown three times earlier that day without incident.

No evidence of jet engine oil getting into the cabin air supply was detected by the AAIU team. However, the aircraft was subsequently flown to Toulouse in France for tests by Airbus engineers which revealed no abnormalities and the plane was returned to normal service.

The AAIU investigator said the fact that anyone with symptoms of drowsiness recovered rapidly after landing would indicate the absence of any toxic contaminant. He also expressed satisfaction that there was no loss of cabin pressure during the flight.

The AAIU report noted that the poor cabin air quality is an ongoing issue in the aviation industry. However, it stressed that there was no question of cabin air contamination in this case.

It criticised the lack of an on-site medical doctor at Dublin Airport and recommended that such medical services should be provided to comply with guidelines of the International Civil Aviation Organisation.

It also pointed out that passengers and crew had been detained on board the aircraft after arriving back in Dublin for more than an hour, despite the possibility that it may have contained dangerous contaminants.