The captain of an Air France plane which crashed into the sea with the loss of all 228 people on board had only slept one hour the previous night after a romantic jaunt in Brazil with his girlfriend. A damning report also found that his co-pilots appeared dangerously tired.
Three young Irish doctors, Jane Deasy (27) from Dublin, Aisling Butler (26) from County Tipperary and Eithne Walls (28) from County Down were killed when AF447 plunged into the Atlantic Ocean as it traveled from Rio de Janeiro in Brazil to Paris in June, 2009.
The close friends had studied medicine together in Trinity College and remained friends after graduating in 2007.
The new revelations may help shed light on why the pilots took what air accident investigators describe as "inappropriate" action when the Airbus 330 flew into turbulence during a tropical thunderstorm.
Co-pilots Pierre-Cedric Bonin, 32, and David Robert, 37, were unable to bring the plane under control as it rolled from side to side. Black box recorders showed that Captain Marc Dubois, 58, had been asleep when the trouble started and took more than a minute to return to the cockpit when they alerted him.
Analysis of the flight recorders has established that airspeed sensors had malfunctioned - probably because they had frozen up. But a report commissioned by French magistrates investigating the crash said the captain had been recorded as grumbling shortly after take off: "I didn't sleep enough last night. One hour is not enough."
The newspaper Le Figaro published a previously unseen email sent by a friend of Captain Dubois showing that he had taken Veronique Gaignard, his girlfriend and an off-duty flight attendant, to Rio.
"I can tell you that he was happy because he told me that he was leaving (for Rio) with Veronique and he was so happy that she was there and accompanying him," the mail reads.
Le Figaro said Captain Dubois and Ms. Gaignard had driven to see friends an hour from Rio and flown by helicopter over the bay during the weekend. When he reached the cockpit after being roused, Captain Dubois used words that suggested he was not fully awake, this according to French press reports.