Passengers and crew of doomed Air France Flight AF447 may have endured a terrorizing last 15 minutes of life according to electronic messages sent by the aircraft.

Details of the automatically generated warning system messages were published today in the Sao Paulo newspaper, le Jornal da Tarde and the British Telegraph newspaper, allegedly obtained from an Air France source.

The data shows the Airbus A300-200 series was flying below the optimal speed for entering turbulent weather conditions before a series of major electronic breakdowns occurred.

According to the Telegraph:

At 3.10am (BST), the pilot was presented with a series of major failures over a four-minute period before catastrophe struck.

At this time, the automatic pilot was disconnected – either by the pilot or by the plane’s inbuilt security system, which flips to manual after detecting a serious error.

At the same moment, another message indicates that the “fly-by-wire” electronic flight system which controls the wing and tail flaps shifted to “alternative law” – an emergency backup system engaged after multiple electricity failures. This system enables the plane to continue functioning on minimum energy but reduces flight stability. An alarm would have sounded to alert the cabin crew to this.

Two minutes later, another message indicates that two essential computers providing vital information on altitude, speed and flight direction ceased functioning correctly.

Two new messages at 3.13am report electricity breakdowns in the principal and auxiliary flight computers.

At 3.14am, a final message reads “cabin in vertical speed”, suggesting a sudden loss of cabin pressure, either the cause or the consequence of the plane breaking up in mid-air.

The suggestion that the pilot gradually lost control of the plane appears to counter reports that the plane exploded in mid-air.

The mid-air explosion theory was given more weight today after a Spanish pilot in the vicinity at the time reported seeing an “intense white flash”.

“Suddenly we saw in the distance a strong and intense flash of white light, followed by a downward, vertical trajectory which broke up into six segments,” the chief pilot of an Air Comet plane from Lima to Madrid told the Spanish newspaper, El Pais.

Some experts have supported the theory that the plane exploded, given the wide area where debris has been found.

However, Brazil’s defense minister, Nelson Jobim, said an explosion was “improbable” given the 13-mile (21km) trail of kerosene spotted on the sea. “If we have fuel slicks, it’s because it didn’t burn,” he said.

Air France flight AF447 departed Brazil’s Airport do Galeao in Rio de Janeiro on Sunday at 2230 GMT for Paris and was last heard from flying at an altitude of 10,600 meters (35,000 feet) at 0133 GMT Monday.

The relatively new Airbus A300-200 jetliner was carrying 126 men, 82 women, seven children and a baby – plus a highly experienced 12-person crew.