A faulty altimeter played a role in a Turkish Airlines crash that killed nine people in the Netherlands, investigators said Tuesday.
The Boeing 737-800 was on autopilot when it was landing at Amsterdam's Schiphol Airport and a problem with the altimeter, a device that measures altitude, led to a loss of airspeed before the crash, according to officials with the Dutch Safety Authority.
Flight 1951 was carrying 135 passengers and crew when it crashed into a muddy field about one kilometre short of the runway on Feb. 25.
Survivors of the crash said there was a violent shudder before the plane suddenly dropped, slammed its tail into the ground and broke into three pieces.
Five Turks and four Americans were killed in the crash.
Chief investigator Pieter van Vollenhoven said when the plane was about 700 metres above the ground it registered a sudden change in altitude.
"It didn't only register it, but passed it on to the automatic steering system," Van Vollenhoven said.
According to recorded conversation involving the plane's captain, first officer and an apprentice pilot in the cockpit, the faulty altimeter was noticed but wasn't considered a problem.
Gas to the engines was reduced and the plane lost speed, decelerating until, at a height of 150 metres, the plane was about to stall and warning systems alerted the pilots.
According to information on the data recorders, the pilots then gave the plane full gas but it was too late to recover, Van Vollenhoven said.
The pilots had been unable to see the runway during the descent because of cloudy and rainy weather, he said.
The airplane had twice before experienced problems with its altimeter, Van Vollenhoven said, and Boeing has been instructed to warn clients about the issue.
Turkish Airlines has had several serious crashes since 1974, when 360 people died in the crash of a DC-10 near Paris after a cargo door came off. More recently, in 2003, 75 died when an RJ-100 missed the runway in heavy fog in the southeastern Turkish city of Diyarbakir.