AMSTERDAM – Investigators said Wednesday a faulty altimeter played an important role in a Turkish Airlines crash that killed 9 people in the Netherlands.
The Dutch Safety Authority said the plane was being landed on automatic pilot and the problem with the altimeter, a device that measures altitude, led to a loss of airspeed before the crash.
The Boeing 737-800 carrying 135 passengers and crew went down in a muddy field one kilometer (less than a mile) short of the runway at Amsterdam's Schiphol Airport shortly before it was due to land on Feb. 25.
Chief investigator Boeing has been instructed to warn clients of the problem, he said.said the airplane had twice before experienced problems with its altimeter.
(AP Photo/Ibrahim Usta) - Turkish pilots salute as they stand next to the coffin of their colleague Olgay Ozgur during a ceremony outside the Turkish Airlines headquarters in Istanbul, Turkey, Saturday, Feb. 28, 2009. Turkish Airlines held a funeral service for three pilots and a flight attendant who died when its Boeing 737-800 crashed in a field near Amsterdam airport three days ago, shattering into three pieces. Hundreds gathered outside the Turkish Airlines' Istanbul headquarters to paid tribute to pilots Hasan Tahsin Arisan, Olgay Ozgur and Murat Sezer and flight attendant Ulvi Murat Eskin.
At 1950 feet (around 700 meters) "the airplane's left radio altimeter suddenly registered a change in altitude" of negative 8 feet (about 2 meters). "It didn't only register it, but passed it on to the automatic steering system," Van Vollenhoven said.
Van Vollenhoven said it was not unusual to land a plane on autopilot.
According to conversation recorded between the plane's captain, first officer and an extra first officer on the flight, the pilots noticed the faulty altimeter but didn't consider it a problem and didn't react, Van Vollenhoven said.
Gas to the engines was reduced and the plane lost speed, decelerating until, at a height of 450 feet (150 meters) the plane was about to stall, andalerted the pilots.
"From the "black box" (data recorders) 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 — cloudy with a light rain.
The plane fell into a freshly plowed field, striking the ground tail first and breaking into three pieces.
Those killed in the crash included five Turks and four Americans.
said the dead included the pilots.The American dead included three Boeing employees on a business trip unrelated to the flight.