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With a complete loss of electrical power there isn't much for the FDR to record other then airspeed, altitude, and attitude from the standby instruments. Howeve

With a complete loss of electrical power there isn't much for the FDR to record other then airspeed, altitude, and attitude from the standby instruments. However that's already available from radar, ADS-B, and in this case, video. CVR might have some value, but again in most cases you're just getting a bunch of yelling and swearing before the crash. As far as understanding what went wrong with Jeju 2216, the interesting bits are going to be right up until they lost both engines, after that it's fairly straightforward to put together the chain of events.

timewizard 2y ago
> there isn't much for the FDR to record other then airspeed, altitude, and attitude from the standby instruments. You forgot the _most_ important data. The position of the flight controls set by the crew. > but again in most cases you're just getting a bunch of yelling and swearing before the crash. That has not been my experience. You can hear the pilots trying to work the problem until the last minute and hearing how they made decisions is important. You can also hear the engines, the wind noise, cockpit warning horns, and possible sources of pilot interference.
- MadnessASAP 2y ago
  > That has not been my experience. You can hear the pilots trying to work the problem until the last minute and hearing how they made decisions is important. You can also hear the engines, the wind noise, cockpit warning horns, and possible sources of pilot interference. Knowing the pilots were trying to prevent the inevitable crash right up until the end is a nice thing to know but now relevant for flight safety. The point of the investigation is to determine what went wrong before the crash became a certainty. Which for Jeju was the moment they lost both engines. > You forgot the _most_ important data. The position of the flight controls set by the crew. While manual flight controls are a thing, without hydraulic assistance they are really only useful if you're trying to maintain straight and level flight while you start backup power. W1ith compounding problems it gives you a little more control of which direction you will be crashing in. I won't deny that more data in an investigation is always useful, but the cost of ensuring that data is available has to be weighed against the potential value of that data. With this crash the data after the loss of both engines won't have much bearing on preventing the similar incidents in the future. To put it another way, should your commercial air liner lose both engines at 1000' in a descent the outcome will be crash, the objective is to prevent that scenario.
  - phoronixrly 2y ago
    Some sources would be beneficial here.
    - MadnessASAP 2y ago
      Certainly, for a more authoritative discussion on "manual reversion" on a 737 see here (https://aviation.stackexchange.com/questions/77693/are-737-pilots-required-to-train-in-manual-reversion-flight https://aviation.stackexchange.com/questions/77693/are-737-p...), your favorite search engine can also provide a decent body of technical and anecdotal data. As far as survivability of suddenly losing all engines at low altitude, I relied on my own knowledge and experience, however I can refer you to Wikipedia (https://en.wikipedia.org/wiki/List_of_airline_flights_that_required_gliding https://en.wikipedia.org/wiki/List_of_airline_flights_that_r...). Specifically https://en.wikipedia.org/wiki/American_Airlines_Flight_1572 https://en.wikipedia.org/wiki/American_Airlines_Flight_1572 and https://en.wikipedia.org/wiki/US_Airways_Flight_1549 https://en.wikipedia.org/wiki/US_Airways_Flight_1549. Those 2 are just about (IMO) the complete body of cases where there was something to learn from the aircrews actions following the loss of power. That being said, there actions were very specific to their circumstances, would be very difficult to train for, and the pilots survived to provide first hand accounts instead of relying on the CVR.
      - phoronixrly 2y ago
        My guy, it's on you to provide your sources, not on me to look for them with my favourite search engine. Thank you for the concrete links apart from that advice.
        MadnessASAP 2y ago
        My bro, It's not on me to provide anything, it's a message board it's everything here is implicitly freely offered opinion. However, I did provide a link, I also noted that in addition to that link, should you or anybody else want to know more, searching 737-800 manual reversion does in fact return a variety of useful information.
phire 2y ago
> However that's already available from radar, ADS-B Not in this case. ADS-B was lost at the same time as the flight recorders. If there was a primary radar in range, they might be able to recover groundspeed and a 2d flight path. But those have been falling out of fashion, and were never that good for things near the ground.
Dalewyn 2y ago
>you're just getting a bunch of yelling and swearing before the crash. Even that is valuable information for discerning what went wrong and how.

timewizard 2y ago

> there isn't much for the FDR to record other then airspeed, altitude, and attitude from the standby instruments. You forgot the _most_ important data. The position of the flight controls set by the crew. > but again in most cases you're just getting a bunch of yelling and swearing before the crash. That has not been my experience. You can hear the pilots trying to work the problem until the last minute and hearing how they made decisions is important. You can also hear the engines, the wind noise, cockpit warning horns, and possible sources of pilot interference.

MadnessASAP 2y ago
> That has not been my experience. You can hear the pilots trying to work the problem until the last minute and hearing how they made decisions is important. You can also hear the engines, the wind noise, cockpit warning horns, and possible sources of pilot interference. Knowing the pilots were trying to prevent the inevitable crash right up until the end is a nice thing to know but now relevant for flight safety. The point of the investigation is to determine what went wrong before the crash became a certainty. Which for Jeju was the moment they lost both engines. > You forgot the _most_ important data. The position of the flight controls set by the crew. While manual flight controls are a thing, without hydraulic assistance they are really only useful if you're trying to maintain straight and level flight while you start backup power. W1ith compounding problems it gives you a little more control of which direction you will be crashing in. I won't deny that more data in an investigation is always useful, but the cost of ensuring that data is available has to be weighed against the potential value of that data. With this crash the data after the loss of both engines won't have much bearing on preventing the similar incidents in the future. To put it another way, should your commercial air liner lose both engines at 1000' in a descent the outcome will be crash, the objective is to prevent that scenario.
- phoronixrly 2y ago
  Some sources would be beneficial here.
  - MadnessASAP 2y ago
    Certainly, for a more authoritative discussion on "manual reversion" on a 737 see here (https://aviation.stackexchange.com/questions/77693/are-737-pilots-required-to-train-in-manual-reversion-flight https://aviation.stackexchange.com/questions/77693/are-737-p...), your favorite search engine can also provide a decent body of technical and anecdotal data. As far as survivability of suddenly losing all engines at low altitude, I relied on my own knowledge and experience, however I can refer you to Wikipedia (https://en.wikipedia.org/wiki/List_of_airline_flights_that_required_gliding https://en.wikipedia.org/wiki/List_of_airline_flights_that_r...). Specifically https://en.wikipedia.org/wiki/American_Airlines_Flight_1572 https://en.wikipedia.org/wiki/American_Airlines_Flight_1572 and https://en.wikipedia.org/wiki/US_Airways_Flight_1549 https://en.wikipedia.org/wiki/US_Airways_Flight_1549. Those 2 are just about (IMO) the complete body of cases where there was something to learn from the aircrews actions following the loss of power. That being said, there actions were very specific to their circumstances, would be very difficult to train for, and the pilots survived to provide first hand accounts instead of relying on the CVR.
    - phoronixrly 2y ago
      My guy, it's on you to provide your sources, not on me to look for them with my favourite search engine. Thank you for the concrete links apart from that advice.
      - MadnessASAP 2y ago
        My bro, It's not on me to provide anything, it's a message board it's everything here is implicitly freely offered opinion. However, I did provide a link, I also noted that in addition to that link, should you or anybody else want to know more, searching 737-800 manual reversion does in fact return a variety of useful information.

phire 2y ago

> However that's already available from radar, ADS-B Not in this case. ADS-B was lost at the same time as the flight recorders. If there was a primary radar in range, they might be able to recover groundspeed and a 2d flight path. But those have been falling out of fashion, and were never that good for things near the ground.

Dalewyn 2y ago

>you're just getting a bunch of yelling and swearing before the crash. Even that is valuable information for discerning what went wrong and how.