Authorities investigating the disaster plan to look into what caused the black boxes to stop recording, South Korea's transport ministry says.

Summary

A Jeju Air Boeing 737-800 crashed at Muan International Airport, South Korea, killing 179 people, with only two crew members surviving. The black boxes stopped recording four minutes before the crash.

Authorities are investigating the cause of the malfunctioning black box. They suspect a bird strike, as feathers were found in one engine, and video footage confirmed a bird impact. However, the exact cause of the crash remains elusive.

Investigators are probing why the landing gear wasn’t deployed, the role of power failure in missing black box data, and the construction of the airfield wall the plane hit.

  • @ThrashyEnglish
    13•1 day ago

    Hydraulics and electric system are independent in commercial aircraft – hydraulic pumps are directly driven from the engines, as are electrical generators. Redundancy is provided via independent loops/buses from each engine. A bird strike on its own is unlikely to be energetic enough to sever one of those independent systems, let alone all four. Losing both engines could do it, – but again, they had enough thrust to attempt a go-around, so they weren’t a glider immediately after the bird strike. The 737 is an old-school design, too, so most critical components have full manual reversion – as long as you have airspeed and altitude enough to get to the runway, you can fly and land the plane just with cable controls and manual releases in the event of total electric and hydraulic failure.

    I did a bit of reading from other sources and this particular aircraft predates the requirement for battery backup of the FDR and CVR, and the APU does not start up automatically on a power failure, so the failure chain for that part of the incident isn’t as long as I initially thought. Still, lots of questions, and I think the simplest explanation so far is the aircrew panicking and making a survivable situation into a bloodbath.

    • EnorilEnglish
      1•22 hours ago

      I wonder if they had an electrical fire under the cockpit while flying.

      The loose of systems normally segregated with multiple backup, the strange 2nd approach too fast without using the gears or flap…

      Total chaos and panic… or system damaged because of the impact with birds… or a drone? Damaged battery can produce a lot of heat and fire…

    • @[email protected]English
      5•1 day ago

      Hmm. Fair enough.

      Looking at a couple other sources, it also sounds like ADS-B data stopped being transmitted prior to the landing. So that does seem like another data point besides the data recorder maybe cutting out arguing for some measure of electrical issues (which doesn’t necessarily mean that the electrical system is damaged, but for power not to be going to part of the plane’s systems).

      https://www.flightradar24.com/blog/jeju-air-2216-muan/

      The last ADS-B message received from the aircraft occurred at 23:58:50 UTC with the aircraft located at 34.95966, 126.38426 at an altitude of 500 feet approaching Runway 1 at Muan.

      Based on visual evidence (see video below, viewer discretion advised) and the altitude and vertical rate data received by Flightradar24, we believe that the final ADS-B messages received represent preparation for a possible flypast of the airport. A flypast is often performed to visually confirm that the landing gear is either down or not prior to making a decision on next steps. The chart below shows the altitude and reported vertical rate of the aircraft from 2000 feet to the last signal received at 500 feet.

      Post-ADS-B data

      It appears that ADS-B data was either no longer sent by the aircraft or the aircraft was outside our coverage area after 23:58:50 UTC. Based on coverage of previous flights and of other aircraft on the ground at Muan before and after the accident flight, we believe the former explanation is more likely. There are multiple possible explanations for why an aircraft would stop sending ADS-B messages, including loss of electrical power to the transponder, a wider electrical failure, or pilot action on the flight deck.

      EDIT: I did also see a pilot talking about the video and pointing out that while the crew didn’t get flaps or gear, they managed to deploy at least one thrust reverser. I’m not sure what drives that (Do you need hydraulics? Electricity?), but it might say something about what was available to them.