Officials warn that the cause of Monday's Lion Air crash in Indonesia won't be determined until the plane's black boxes are recovered, but some clues point to a possible problem with what the New York Times refers to as "a small metal tube." Satellite data shows Lion Air Flight 610 took an erratic path after taking off, with unpredictable fluctuations in speed, altitude, and direction. It initially reached an altitude of 2,100 feet shortly after takeoff, then fell sharply to 1,475 feet before quickly ascending again to altitudes between 4,500 and 5,350 feet, then going into its final steep decline. (The Times has a graphic showing the flight path and how it varied from a normal flight.) Such dramatic changes could indicate a problem with the plane's pitot tubes, indicators used to calculate airspeed and altitude. The tubes have been implicated in other crashes. More of the latest, including eerily similar problems the night before:
- What is a pitot tube? The slender, perforated tubes each have two holes and are located on a plane's wings or fuselage. An airstream flows into the hole in the front; the differences in "stagnation pressure" at the front and "static pressure" at the side are measured to calculate airspeed. If the plane is going too slowly, it could stall; if it is going too fast, it could break apart. Ice crystals formed over the tube's intake on Air France Flight 447, leading to incorrect measurements and, thus, improper reactions from the flight crew; the flight ultimately disappeared over the Atlantic in 2009.