7 ms·

One possible scenario is that they had a bird strike on one engine but then accidently turned the working engine off instead. Full loss of power from both engin

One possible scenario is that they had a bird strike on one engine but then accidently turned the working engine off instead. Full loss of power from both engines could have taken the data recorder offline in an older aircraft like this one. With both engines off, they may have panicked to try to complete a tight turn to return to the airport and to maintain altitude to make it to the runway. It's possible the landing gear was forgotten but also possible that it was intentional (to extend glide.) It's too early to know anything with certainty but I suspect that the investigation will show that a different set of choices would have allowed them to put the plane down safely (for example by continuing with the initial approach.) Even in that case, they may not have been to blame - for example they may have been following a standard procedure that should be revisited.

Over2Chars 2y ago
I was under the impression that these CDR/FDRs were independently powered. But a quick Quack on DuckDuckGo didn't answer anything. That two different recorders both went titsup at the same time I find mind boggling and very sus. edit: apparently they have both AC and a battery backup, if the internet is to be believed. Which makes a simultaneous loss of two devices with battery backups... curious. Did they get hit with an EMP?
- f1shy 2y ago
  If the motor was just shutdown, it should still make power off windmilling. If they discharged the extinguishers, then there is no more power. In any case, that should be recorded.
- SteveVeilStream 2y ago
  Battery backup was not required until 2010. This aircraft was manufactured in 2009. https://www.ecfr.gov/current/title-14/chapter-I/subchapter-G/part-121/subpart-K/section-121.359 https://www.ecfr.gov/current/title-14/chapter-I/subchapter-G...
  - jiggawatts 2y ago
    The general populace seems convinced that black box recorders are made of adamantium and can return data even if the plane falls into a black hole. Meanwhile every time I read about a crash, I'm horrified by how primitive the requirements (and implementation) appear to be. This reminds me of my favourite method for reviewing software I had never heard of: I check the release notes. If version v17 has "now uses transactions" then that means that the developers were happy to release the first sixteen major versions with data corruption as a feature. (Conversely, if the notes only mention fantastically obscure scenarios being fixed, then the basic issues have been fixed long ago.) Battery backup being introduced in 2010 as a requirement is absolutely insane. It's not like batteries or battery backup are new technologies! This stuff has been around forever. Why on earth was this not a requirement decades ago!?
    - lotsofpulp 2y ago
      I find it just as crazy that many or most personal cars come equipped with cameras and sensors all over, but are not required to record any of it for analysis of a collision and attribution of fault. The most unqualified person can be driving a 10,000 pound (4,500kg) electric Hummer and have no measures in place to use the built in cameras and sensors to determine what went wrong in the event of a collision. Hell, there are cameras inside the vehicle that can tell us whether or not a driver was using their phone when a crash happens, but it does not seem politically popular to enforce reviewing this footage, even though being in a personal car is far more dangerous than being a passenger on a plane.
      - SR2Z 2y ago
        This is not strictly true and most cars have black box modules which record control inputs and IMU data.
        lotsofpulp 2y ago
        I have never heard of this used to determine who is at fault in a collision. Does that happen? Also, video would be a tremendous help for ascribing proper blame, so why wouldn’t that be required? When airbags came out, video recording was expensive, but that has long not been the case.
- dist-epoch 2y ago
  Even if the FDR is powered, if the flight computers/systems are without power there is nothing to record.
dzhiurgis 2y ago
Batteries are there for at least 30 minutes
- SteveVeilStream 2y ago
  Not required for planes manufactured before 2010. https://www.ecfr.gov/current/title-14/chapter-I/subchapter-G/part-121/subpart-K/section-121.359 https://www.ecfr.gov/current/title-14/chapter-I/subchapter-G...
f1shy 2y ago
Note that just shutting down normally the engine would not cause a power loss. Only in the case of a turn off with extinguisher. Of course after bird strike you shut it down with extinguisher. Now there is clear procedure, with checks that has to be memorized, where you first identify the engine. Pilots are regularly tested for that procesures. Why it went wrong?
- _cenw 2y ago
  I remember that Boeing changed which pack provides air conditioning to the cockpit between the 737-200 and the 737-300, which lead to a few similar situations in which pilot were confidently wrong which engine was bad based on smell alone.
  - gorm 2y ago
    It was changed in 737-400. Before it only took air from the right engine, but 737-400 took from both. In the Kegworth air disaster, which was caused by a failed blade and the system causing a fire trying to compensate by injection of more fuel, the pilot assumed the fire was in right engine and turned it off as crew never notified them which engine was burning. When they discovered the error the speed was too low to kickstart the engine. https://en.wikipedia.org/wiki/Kegworth_air_disaster https://en.wikipedia.org/wiki/Kegworth_air_disaster
    - yetihehe 2y ago
      You would think that such a complicated machine would have some better method to notify pilot which engine failed, instead of "does it smell like right or left engine".
      - 0_____0 2y ago
        There are a series of gauges associated with each engine, but in a high workload situation it might take some effort to make sense of them.
    - _cenw 2y ago
m463 2y ago
It could also be a flock of birds damaging all the engines.
mysterydip 2y ago
Does the APU automatically start or is it a manual process?
- thedrbrian 2y ago
  Manual process.

Over2Chars 2y ago

I was under the impression that these CDR/FDRs were independently powered. But a quick Quack on DuckDuckGo didn't answer anything. That two different recorders both went titsup at the same time I find mind boggling and very sus. edit: apparently they have both AC and a battery backup, if the internet is to be believed. Which makes a simultaneous loss of two devices with battery backups... curious. Did they get hit with an EMP?

f1shy 2y ago
If the motor was just shutdown, it should still make power off windmilling. If they discharged the extinguishers, then there is no more power. In any case, that should be recorded.
SteveVeilStream 2y ago
Battery backup was not required until 2010. This aircraft was manufactured in 2009. https://www.ecfr.gov/current/title-14/chapter-I/subchapter-G/part-121/subpart-K/section-121.359 https://www.ecfr.gov/current/title-14/chapter-I/subchapter-G...
- jiggawatts 2y ago
  The general populace seems convinced that black box recorders are made of adamantium and can return data even if the plane falls into a black hole. Meanwhile every time I read about a crash, I'm horrified by how primitive the requirements (and implementation) appear to be. This reminds me of my favourite method for reviewing software I had never heard of: I check the release notes. If version v17 has "now uses transactions" then that means that the developers were happy to release the first sixteen major versions with data corruption as a feature. (Conversely, if the notes only mention fantastically obscure scenarios being fixed, then the basic issues have been fixed long ago.) Battery backup being introduced in 2010 as a requirement is absolutely insane. It's not like batteries or battery backup are new technologies! This stuff has been around forever. Why on earth was this not a requirement decades ago!?
  - lotsofpulp 2y ago
    I find it just as crazy that many or most personal cars come equipped with cameras and sensors all over, but are not required to record any of it for analysis of a collision and attribution of fault. The most unqualified person can be driving a 10,000 pound (4,500kg) electric Hummer and have no measures in place to use the built in cameras and sensors to determine what went wrong in the event of a collision. Hell, there are cameras inside the vehicle that can tell us whether or not a driver was using their phone when a crash happens, but it does not seem politically popular to enforce reviewing this footage, even though being in a personal car is far more dangerous than being a passenger on a plane.
    - SR2Z 2y ago
      This is not strictly true and most cars have black box modules which record control inputs and IMU data.
      - lotsofpulp 2y ago
        I have never heard of this used to determine who is at fault in a collision. Does that happen? Also, video would be a tremendous help for ascribing proper blame, so why wouldn’t that be required? When airbags came out, video recording was expensive, but that has long not been the case.
dist-epoch 2y ago
Even if the FDR is powered, if the flight computers/systems are without power there is nothing to record.

dzhiurgis 2y ago

Batteries are there for at least 30 minutes

SteveVeilStream 2y ago
Not required for planes manufactured before 2010. https://www.ecfr.gov/current/title-14/chapter-I/subchapter-G/part-121/subpart-K/section-121.359 https://www.ecfr.gov/current/title-14/chapter-I/subchapter-G...

f1shy 2y ago

Note that just shutting down normally the engine would not cause a power loss. Only in the case of a turn off with extinguisher. Of course after bird strike you shut it down with extinguisher. Now there is clear procedure, with checks that has to be memorized, where you first identify the engine. Pilots are regularly tested for that procesures. Why it went wrong?

_cenw 2y ago
I remember that Boeing changed which pack provides air conditioning to the cockpit between the 737-200 and the 737-300, which lead to a few similar situations in which pilot were confidently wrong which engine was bad based on smell alone.
- gorm 2y ago
  It was changed in 737-400. Before it only took air from the right engine, but 737-400 took from both. In the Kegworth air disaster, which was caused by a failed blade and the system causing a fire trying to compensate by injection of more fuel, the pilot assumed the fire was in right engine and turned it off as crew never notified them which engine was burning. When they discovered the error the speed was too low to kickstart the engine. https://en.wikipedia.org/wiki/Kegworth_air_disaster https://en.wikipedia.org/wiki/Kegworth_air_disaster
  - yetihehe 2y ago
    You would think that such a complicated machine would have some better method to notify pilot which engine failed, instead of "does it smell like right or left engine".
    - 0_____0 2y ago
      There are a series of gauges associated with each engine, but in a high workload situation it might take some effort to make sense of them.
  - _cenw 2y ago

m463 2y ago

It could also be a flock of birds damaging all the engines.

mysterydip 2y ago

Does the APU automatically start or is it a manual process?

thedrbrian 2y ago
Manual process.