Cockpit voice recorder survived fiery Philly crash—but stopped taping years ago
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This recorder was 80s technology, basically an analog recording device, sealed in a bomb proof box. What diagnostic functions did it even have? Maybe a small lamp that indicates it's "ON"?
I'm sure modern solid state recorders have better built in diagnostics, and could change the LED color from red to green once it's little computer was powered up and operating properly. That would be easy to verify the unit was both powered on, AND functioning.
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I think what you meant is that the NTSB will recommend that maintenance programs have procedures for testing the CVR audio, and the crickets in the FAA offices emptied out by Musk will go right on chirping.
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Hah. You are too trusting. I have encountered more than a few "modern" electronic devices with built in diagnostics that indicated that everything was a-ok. Except that it wasn't. I want a button that does something.
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I can only speak for the SOP on my aircraft, but we press the CVR self-test button before the first flight of the day. Not the first flight of the aircraft of the day, but our first flight of the day in an aircraft.
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Thank you for your service. Not being facetious; its just nice to hear someone taking their job seriously.
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Those would have been solid state CVRs, which were introduced in the 90's. Tape CVRs can't rewind due to the way the endless tape loop works, so playback isn't really an option. AFAIK the only indicator for tape units is if the breaker is turned on.
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I know this has always been a thing, but it seems likely it was a relic of the past: one device records what the microphones collect in the cockpit, and another device records what all the various sensor collect throughout the aircraft. But if you think about it today, it sure seems like you could easily have two devices, and each one records everything from all microphones/sensors. So even if, say, the microphones recorded on to one device, it seems like it should be easy to have that recording (MP3 files?) also saved? backed-up? via wire or wireless? to the other device. Same with the other sensors. You now have two recorders, each with all the data, and therefore you only need to recover one to have a complete data set.
Just as a mental exercise, imagine iPhones as the recording devices -- they likely have plenty of processing power, storage and networking, for 30 minutes worth of data, for at most $2K each.
Obviously the real black boxes would need to be similar, but more more hardened, could have massively more storage so instead of only 30 minutes you could maybe have months worth of flight data stored, etc, etc. That also brings up another possibility: if you can store say 3 months worth of flight data, then once a month you offload the data -- test it to make sure it's working, woo hoo! -- and archive it all for future evaluation, so you can catch problems that happened in the past that had not been noticed real-time.
Fun to think about.
"If you do not test your backups, you have no backups!"
(If you want to, google that, you'll see this is a well-understood saying)
For many years I was the SQL Server DBA (database administrator) for a number of federal government agencies, and the most fundamental role of a DBA is to make sure there were backups. And that thinking is wrong!
The most fundamental purpose of a DBA is to make sure backups can be successfully restored. You cannot imagine -- literally, you can't imagine -- all the numerous ways backups can be such that they cannot be restored. The one and only way to make sure your backups are working is to do restores on a regular basis. This was the most fundamental thing I set up at each new agency (after my head exploded when I found out they weren't even doing backups at all!) We had at least monthly, and sometimes weekly, test-restores actually performed, burned right into our schedule, mandatory, no exceptions. Management hated this -- just like they hate backups -- because they don't see any 'progress' being made on anything, when executing on your comprehensive data retention plan. And they are right. Backups -- and more importantly the test-restores -- work just like insurance: insurance is the biggest waste of time and money, until you need it, then it is the best investment you ever made. Management needed to be cracked upside the head frequently to drill this home. It seems like the airline industry still hasn't learned their lesson. And of course what that means is that since the recorder wasn't working, investigators might never figure out what really happened, so the same damn thing might happen again, and because someone didn't implement proper testing into their maintenance plan. This is not hard. This is well understood. There is no excuse for that shit.
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All you'd have to do is have the tape pass the read head after passing the write head, then ensure that a tone getting recorded by the write head is getting picked up by the read head.
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Keep in mind a plane of this era doesn't have "data" streaming to the flight controls. I think Learjets at the time were using purely mechanical pushrods and cables to connect the yoke and pedals to the control surfaces.To me, it seems like planes should not be allowed to take off without this data streaming through black box, and afterwards, streaming past the black box (as in it needs to go past the black box to exit the aircraft) in order for the plane to be allowed to take off. What do I know? however. I'm just some engineer.
That's not to say you can't find ways to log data, but there's no way a black box can block a mechanical linkage from operating.
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Point, and I can't find a good detail image of one to confirm either way. Edit: Looking at other forums (where I should have looked first) it appears that you are correct. TILS.
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Most light aircraft are that way. That's why GA aircraft aren't required to have FDRs, they don't have power assist or FBW so there is nothing instrumented for the FDR to record.
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I think this was a joke on “news from the future”. Musk is gutting many of the safety features of the US government. Any day now articles will start appearing about completely preventable tragedies if the NOAA or park rangers were properly staffed. It will not be surprising at all if aviation safety is on his hit list so he can make a flying car.
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If it's literally "fowl play" your culprit is probably Feathers McGraw.
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If you aren't nose first, that means you either glided into the crash or had a sort of free fall.
If the former, your downard velocity isn't so great. You can safely land a plane without engines, after all.
If the latter, then the fastest you would be going is the terminal velocity of the airframe. I couldn't find a good source on this, but it seems like a couple hundred mph at most.
Where you get into trouble is if the plane's forward velocity is pointed directly at the ground. Now you're going really fast. And your tail is in the back since you are nose first.
Not perfectly, of course. But the less nose first you are, the slower you are generally going in the direction of the ground.
I'm not an aviation person but I think the physics work out this way.
Edit: The exception being if you somehow manage to turn the plane around so that the tail is on the front. I suppose stunt planes or fighter jets can do this, but I doubt it's a situation commercial airliners would ever find themselves in.
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One of Kyra Dempsey's ("Admiral Cloudberg") articles talks about reconstructing the crash of Air Algerie 5017 (an MD-83) in the Sahara. The investigators found the CVR, in pieces, while surrounded by French Army troops holding armed jihadists at bay. They brought all the fragments of shredded tape to France and painstakingly spliced them back together in a BEA lab, only to find that the device's erase head had failed 13 flights ago and it had just been looping ever since, sound overlaid on sound for 13 cycles, with no way to tease out anything useful.
That must be an interesting, but terribly frustrating, job.
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The technology to do that has existed for a while now. Many planes have them as an optional feature. It's called a quick access recorder (QAR) and it is the first place you look when a plane has had some kind of issue in flight.
The CVR and FDR are mandated by ICAO and FAA regulations. Personally, I think those regulations can and should be amended to allow a total-data recorder that saves flight, voice, instrument, GPS, etc. data and that is duplicated (one under the cockpit, one in the tail) with total redundancy. But the rules currently specify separate recorders.
Keep in mind this is an industry where people flip out because a particular through-hole electrolytic capacitor from 1982 was explicitly called out by part number in a particular circuit board, and now that cap is discontinued, and requalifying the board to use a modern alternate part is a regulatory PITA. Regulatory inertia is a thing, and is hard to fight.
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All I can think about is the poor little girl who endured 4 MONTHS of medical treatment far away from home only to die horrifically within minutes of takeoff. All the deaths are tragic, of course, but as a father that detail sticks in my craw.
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But then you still have to account for the difference in not having a huge crumple zone between the box and the ground.
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1/ The NTSB do not just pointlessly lie.
2/ If they did say something obviously counterfactual then it would be apparent and someone would dispute it.
3/ Get a grip. They're doing actual things you should be getting worked up about, you don't need to make up nonsense.
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Here's a description (PDF) of a tape CVR from a different Learjet. It does have a test function -- there's a monitor head after the erase and write heads. The pilot can plug in a headset to listen to the test tone. There's also a meter indicating the sound level on the monitor.
If it was "years" not only was it not being tested, it was probably way past its service interval. The tape has to be replaced after a certain number of flight hours. There's also a water jacket that boils off in a fire. It's supposed to be weighed to verify that it's still full.
If it was "years" not only was it not being tested, it was probably way past its service interval. The tape has to be replaced after a certain number of flight hours. There's also a water jacket that boils off in a fire. It's supposed to be weighed to verify that it's still full.
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HuntingManatees
Ars Centurion
Do stretchers on a medical flight count as passenger seats?
This probably sounds like a stupid joke question, but I know the FAA does make what seems to me like a similar distinction -- although obviously for different reasons -- between lithium batteries on a drone as payload versus those connected to the powertrain, even if they're the exact same model of battery.
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HuntingManatees
Ars Centurion
This is a feature of conspiratorial thinking, not a bug.
Actual government subterfuge and corruption can be rooted out, at least in theory, leaving you with no one to hang your manufactured grievance on. It's partly why so many conspiracy theories involve the supernatural -- that, and you get say that all Jewish people are lizards or demons or whatever.
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Airline pilot here: we test it every single flight. It’s a single button you press and hold for 2-3 seconds as part of the normal cockpit scan, at least on the types I’ve flown.
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Also, usually the aircraft manufacturer and/or CVR/FDR manufacturer have representatives do the actual recovery of the data, with NTSB observers present. The aircraft manufacturer generally wants that data...
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The NTSB has a whole lab doing such recoveries as full time work. They have way more experience than the manufacturers at that. Outside engineers usually don’t need to be brought in until it comes to interpreting the data. It has the added benefit of ensuring chain of custody of the data.
Obviously, for even more specialized situations — like the EGPWS computer cited at the end of the article — the NTSB lab isn’t equipped to do data recovery and they shipped it off to the manufacturer. So I’m definitely not claiming they never get outside help with these things.
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RickRoyLeonPrisZhoraRacha
Ars Scholae Palatinae
Yes this. And to know how much time the flight crew had to rest since (I'm speculating) they landed in Florida, then flew to Philadelphia, then loaded up medical staff and patient with parent, and then leave for Missouri, and then Mexico.
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Hitting tail first is the expected outcome when a tail-heavy aircraft stalls, typically due to a load shift as with National Airlines Flight 102 or a design fault like the F-104 Starfighter, but any nose-up stall at low altitude will do it.
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I've worked on TAWS systems (a more general system that includes GPWS/EGPWS functionality combined with data from other instruments and systems). Our internal logging capability was primarily for proprietary system debug and performance data, with no specific goal of being any kind of forensic system the NTSB would be interested in accessing.
However, one important function we did incorporate (and carefully log) is continually running quality metrics on our incoming data, our data analysis system, and our own outputs to the pilot, as our system was also required to inform the pilot when system operation was degraded in any, such as via alerts and alarms, and, in extreme cases, by blanking the display or switching to a reversionary display.
We also logged (and displayed a flag) when audible alerts were selectively disabled, something that may be done manually or automatically (via prioritization) to reduce pilot sensory overload in emergency situations. Our instrument was the only one I was aware of that required the cabin audio status to be provided as an input (as part of the System Type Certification for each flavor of aircraft), as we considered it to be a vital bit of information needed to properly perform our primary safety functions.
However, one important function we did incorporate (and carefully log) is continually running quality metrics on our incoming data, our data analysis system, and our own outputs to the pilot, as our system was also required to inform the pilot when system operation was degraded in any, such as via alerts and alarms, and, in extreme cases, by blanking the display or switching to a reversionary display.
We also logged (and displayed a flag) when audible alerts were selectively disabled, something that may be done manually or automatically (via prioritization) to reduce pilot sensory overload in emergency situations. Our instrument was the only one I was aware of that required the cabin audio status to be provided as an input (as part of the System Type Certification for each flavor of aircraft), as we considered it to be a vital bit of information needed to properly perform our primary safety functions.
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I am trying to visualize that particular seat configuration. It sounds like something Spirit or Ryanair would try to sell you: more than not a seat, but less than an actual one.
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Oh, that's right. There was another bird strike incident this week that forced a plane to return to the airport.
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I never hacked a Black Box. But in extra-simple audio recorders, write and read were the same head. Shared/switched electronics too.
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Shame that the recorder wasn't working. It was a tragedy due to loss of life but not even learning anything to help prevent a future mishap adds a bit more sting to it.
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