How Does a Black Box Work? A Look Inside a Flight Data Recorder - The Electronics Inside

[@MAYERMAKES]

the resistors soldered onto the grid are in fact, hardcode programming. its literalyl hardwiring code. soooo coool.

[@Sebastian_Athea]

Those "links" between the bolts are lock wire, it's there to prevent bolts from unscrewing, every single bolt or screw in the aircraft needs to be "locked", it's a safety thing and it doesn't have anything to do with anti tamper, it's usually done with lock wire but some high end machines use self locking bolts instead,, you need an special tool that unlocks those bolts before they can be manipulated but it's far less tedious than dealing with lock wire, and glue like threadlocker is used for smaller screws. Also fia mandates using locking bolts on some race cars for the same reason.

[@CKT1138]

You can't fool me, I know it's just a special edition box for Rammstein's "Reise, Reise" album, everyone knows planes aren't real

[@michaelturner4457]

Rammstein FLUGREKORDER NICHT OFFNEN I got the special edition on vinyl. I thought it looked familiar.

[@a531016]

Sadly it's only 7"

[@gregf9160]

Steel wire recorders were still common-place up until about 20-odd years ago. Also, in fireproof safes, the heat-resistant layer was often ground-up loosely packed glass, as it doesn't conduct heat very well.

[@a531016]

I do remember them making the change to Solid State, but the size, shape and even the sound of it made me think Hard Drive. Even though I knew it didn't make sense!

[@sleepdeprived4244]

I remember seeing these sitting on the shelves ready for servicing when I was building FDRs for the MOD in the early 2000s. It was cool seeing that old technology back then. At the time I was building FDRs for Harriers and I was obsessed with what we called "disk on chip" technology, which everyone now knows as solid state drives. Back then working with what was advanced technology that could store up to 64Gb(!) on something the size of a Kit-Kat was mind blowing.

[@leirex_1]

I went from "I bet it's tape!" to "what? a hard drive? Wouldn't that be too fragile and expensive?" to "HA! it is tape!"

[@harryshector]

400 Hz power is used on aircraft because it reduces the amount of iron/steel needed in motors - transformers, and therefore reduces the.weight of the devices.

[@a531016]

Thank you, that makes sense!

[@andycapp9081]

Not the square windows !!! - but the antenna hole through the fuselage.

[@kreynolds1123]

I suspect the reason for using a higher freqency like 400 hz rather than 50 or 60 hz is weight and size of transformers. One could add that the required capacitance of smoothing capacitors also shrink with higher freqency.

[@lisashipman459]

0:19

[@johnchristopherrobert1839]

Asbestos use is still being allowed in industrial settings. A good example is pump glands “seals”

[@NZHippie]

The Plessey Company made a lot of gear for the Post Office (BT) as well...

[@toddmarshall7573]

5:10 "...assume the frequency the apu runs at...": Isn't it the frequency that the avionics runs at?

[@BogdanSerban]

400Hz is a standard frequency for aviation and military equipment. I built a switching inverter for a gyroscope that came from a tank, it was my graduation thesis.

[@a531016]

Oh, the 400hz carried over to tanks too?! That seems like a strange thing to want to standardise? Are there common or transferable parts (radar / computers / radios systems maybe)?

[@kreynolds1123]

​@@a531016 it's because one can save weight on transformers in power conversion systems. Required capacitance and size from smoothing capacitors also goes down with higher freqency. The generator is also made smaller with a higher freqency. Saving weight and space and money on a tanks and airplanes is probably a useful thing 😊

[@JeremySpidle]

Aircraft use 400Hz AC because transformers in all electronics running off the AC line can have smaller, lighter transformers due to the higher inductive reactance at the higher frequency. It also hurts more...

[@denisconnolly5064]

I didn't see any TTL logic on those boards. Well, not 74 or 54 series TTL logic. I did see extensive use of CMOS logic however.

[@michaelturner4457]

13:55 Yup you wouldn't need it, Becuase the controller part would likely be very trashed if the airplane hit the ground at 500 knts

[@a531016]

I'd love to find photos, or better a video of the recovery tool that I found the listing for!

[@michaelturner4457]

@@a531016 The recovery tools that the companies make, are only supplied to the authorities that handle air accident investigations, like the NTSB. So you're not going to them on KZbin or whatever. That's why you might see news reports about some air disaster, where they might state the black boxes were flown back to Washington DC for analysis.

[@johnchristopherrobert1839]

After seeing what is inside the media storage device. I believe it’s storage capacity will be between 80-120 megabytes.

[@ErrorMessageNotFound]

given that it's magnetic tape, you might be able to "play" it back on a reel to reel tape player and listen to the data.

[@BLOCKsignallingUK]

The tape drive motor is probably separate from the drive as it is likely the most unreliable component of the unit, and would need periodic replacement.

[@johnchristopherrobert1839]

250mb for the hard drive. The drive is only holding raw data. One doesn’t need an incredible of Storage capacity for that job. The only reason that we need gigabytes of storage nowadays is because the programming languages used are very high-level.

[@TheCommuted]

Almost certainly a hydrated salt. Maybe asbestos reinforced calcium sulfate. Basically drywall.

[@Chriva]

Mechanical disk drivers are much too fragile for this application. :) eeprom were still in the kilobytes range and had extremely low endurance (10-100 cycles), eprom not much better (and they required UV to erase) so tape was pretty much the only thing they could use :) Everything was still analogue when that thing was out so whatever system they used after that still had to send the same signals to it. Guess it would be very boring if the tape were to still be there :)

[@michaelturner4457]

Well yeah, mechanical hard drives are absolutely not suitable for a flight recorder. An aircraft hitting the ground at 500-600 knots, that would guarantee a head crash. That's why they used wire, foil, and tape for the recording medium for decades.

[@Malphazar]

thats lock wire on the front panel not a anti tamper

[@liquidsonly]

There are likely people watching this that know *exactly* how this works, but none of then will ever comment because of the Official Secrets Act.

[@michaelturner4457]

I was expecting tape and not a hard-drive in this. More modern FDRs use solid state data storage in an extremely robust enclosure..

[@a531016]

The SSD ones are inside the cylidrical style ones, right?

[@michaelturner4457]

@@a531016 Yeah, that's the ones. That have several layers of fire-proofing and heat protection materials.

[@MAYERMAKES]

how...just how did you get this thing....

[@a531016]

I can't talk about that....

[@coondogtheman]

Since you can't show/play what is on these tapes for privacy or security reasons how about trying to get this tape drive running and record something on it. Such a shame that you can't show what's recorded on this if there is anything.

[@djSouRay]

Do u want to sell???