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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

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.
        SR2Z 2y ago
        It does happen! These devices are generally only installed post-2005ish cars and the data is used more for safety investigations (did this car have a hardware fault) than insurance, simply because it takes a decent amount of skill to construct a narrative off those devices. Video isn't required because even these black boxes, AFAIK, are STILL not required in the US. They also introduce unacceptable privacy compromises for Americans, seeing as how most people subconsciously treat their car as an extension of their living room.
        2y ago
- themaninthedark 2y ago
  Did some airplanes have battery backup before that? It's my recollection of several crashes, where the plane is not immediately recoverable that there is always a concern that the black boxes will overwrite themselves.
  - Over2Chars 2y ago
    There's a slew of models and different methods for recording. The time period they record tends to be very short, but that does raise an interesting question, when do they stop recording?
dist-epoch 2y ago
Even if the FDR is powered, if the flight computers/systems are without power there is nothing to record.

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.
      - SR2Z 2y ago
        It does happen! These devices are generally only installed post-2005ish cars and the data is used more for safety investigations (did this car have a hardware fault) than insurance, simply because it takes a decent amount of skill to construct a narrative off those devices. Video isn't required because even these black boxes, AFAIK, are STILL not required in the US. They also introduce unacceptable privacy compromises for Americans, seeing as how most people subconsciously treat their car as an extension of their living room.
        2y ago
themaninthedark 2y ago
Did some airplanes have battery backup before that? It's my recollection of several crashes, where the plane is not immediately recoverable that there is always a concern that the black boxes will overwrite themselves.
- Over2Chars 2y ago
  There's a slew of models and different methods for recording. The time period they record tends to be very short, but that does raise an interesting question, when do they stop recording?

dist-epoch 2y ago

Even if the FDR is powered, if the flight computers/systems are without power there is nothing to record.