The Dutch Safety Authority said because the plane was being landed on automatic,  pilots were slower to pick up the false height readings.

'Too late'

Boeing has been told it must warn clients about the fault, Van Vollenhoven said.

According to a conversation recorded between the plane's captain, first officer and an extra first officer on the flight, the pilots noticed the faulty altimeter but did not consider it a problem, Van Vollenhoven said.

He said the fault meant fuel to the engines was reduced, causing the aircraft to lose speed to the point of almost stalling at a height of about 150m. It was then that warning systems alerted the pilots.

"From the black box it appears that then the pilots immediately gave gas, full gas, however it was too late to recover," Van Vollenhoven said.

He said that the pilots had been unable to see the runway at the time the plane began its descent due to weather conditions, which was cloudy with a light rain.

The plane, which was en route from Istanbul to Amsterdam, crashed and broke into three pieces.

Five Turks and four Americans were killed and another 86 people injured.