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.
- Similar problem the night before? Lion Air's president director previously revealed that the Boeing 737 MAX 8 that crashed had experienced a technical issue during its previous flight, the night prior, and that the problem was resolved. Experts who looked at data from that flight say that it looks as if the problem had to do with measuring airspeed. The Guardian reports that flight also flew erratically, with irregular changes in speed and altitude including an 875-foot drop during its initial ascent.
- "Panic and vomit": Passengers from that Sunday flight reported a "rollercoaster" ride, with several sudden drops. "About three to eight minutes after it took off, I felt like the plane was losing power and unable to rise," says one passenger, and the same thing happened multiple times. "Some passengers began to panic and vomit." Other passengers say there were also problems with the air conditioning, cabin lights, and a "weird" engine noise that continued throughout the flight.
- Accident investigator weighs in: Multiple experts agree clues seem to point toward pitot tubes. As one explains: "If they are flying on autopilot and the altitude indication goes funny, the aircraft will react. On highly automated aircraft crews can get rapidly overwhelmed when something goes wrong. You can find all sorts of systems dropping out and the crew struggling to cope." He adds that the plane broke up quite a bit upon entering the Java Sea, indicating a complete loss of control rather than an attempt at a controlled ditching.
- Safety of Lion Air called into question: Another aviation safety investigator notes that if the pitot tubes were to blame, "It’s a high-stress technical failure, but the aircraft is quite capable technically of flying to a safe landing. If you go back through the history of Lion Air and its previous incarnations, it’s not an airline I would fly on." In the wake of the crash, Australia has told its officials and government employees not to fly on Lion Air, the Jakarta Post reports.
- Inspection of all planes: Indonesia has ordered that all Boeing 737 MAX 8 planes flown by national commercial airlines be inspected, CNN reports.
- The search continues: All 189 aboard Flight 610 are presumed dead, and 37 body bags of human remains have been recovered. Each body bag could contain remains from more than one person, and officials have warned they don't expect to recover all remains. Officials are working on identification using DNA samples from family members of passengers.
- Final selfie: Some family members of passengers, however, are holding on to hope, Channel News Asia reports. "I hope for a miracle and that he is still alive," says one woman of the husband she married just two weeks ago. He sent her a selfie with the airplane window in the background at 6:12am. By 6:15am, he was no longer replying to her messages. Contact with the plane was lost at 6:32am.
("You could feel the explosion," says a man who was fishing near where the plane went down