Preliminary findings from the recorders of an Air France jet that crashed into the Atlantic Ocean in 2009 have found that the pilots became distracted with malfunctioning airspeed indicators and failed to properly manage other critical systems, the Wall Street Journal reported, citing people familiar with the matter.

The crew did not follow standard procedures to maintain air speed and keep the aircraft's nose level after the Airbus 330 encountered some turbulence and unexpectedly high icing at 35,000 feet, the paper said.

Air France and Airbus were unavailable for comment outside business hours.

The Journal said the cockpit recorders show that the pilots apparently became confused by the alarms blaring from their instruments and despite trying to systematically respond to each warning, were unable to sort out the chaos and maintain a steady course.

The findings from the recorders, which are to be released on Friday, are expected to show that the twin-engine jet slowed dangerously after the autopilot disengaged.

The crash killed all 228 people on board Flight 447, which was on a scheduled flight from Rio de Janeiro to Paris.