Flight Data recorder teardown

[@CristiNeagu]

That "aircraft full of flight recorders" joke reminds me of another one. On the news. the reporter says: "A small, 4 seater, Cessna crashed in a cemetery today. Rescue teams recovered 98 bodies so far, and the numbers is still rising."

[@SkyCharger001]

+Cristi Neagu local caretaker: "are ya daft? all those desecrated graves!" ;)

[@akimbomidget]

Oh and in addition, during a crash, the motor will stop running. So no damage can come to the tape from winding, provided the padding around the tape does its job.

[@mikeselectricstuff]

I'm sure there are probably plenty of tape recorders flying, but new recorders will obviously be using flash memory.

[@TrimeshSZ]

Well, this is probably about 6 years too late, but anyway... The reason the upper connector on the rear panel isn't populated is that that specific unit only has the basic (6 parameter) DAS card in it. There were 5 basic variants of this model, indicated by the first letter of the part number suffix (D = Digital only, needs external FDAU / E = Extended DAS, supports 10 parameters (UK CAA spec) / F = Basic DAS, supports 6 parameters / G = Extended DAS, supports 11 parameters (US FAA spec) / H = Shipped in E configuration but can be expanded to G by installing the extended DAS card) The config code is on the end of the part number - in your case FWUS - so F = Basic DAS / W = Pitot/Static with Wiggins connectors / U = ULB Installed at shipment / S = Standard case. The BITE LED on the front panel is indeed Built In Test Equipment - this unit also had a (for the time) advanced feature where every time it wrote a block on the tape it then wound the tape back and verified it, so it could detect write failures in normal operation. The connector on the front panel is for dumping the data - either directly to a system (based on a Data General Nova 4!) called ADRAS or indirectly using a copy recorder that dumped the internal data onto 1/4" reel-to-reel tape. Very slowly.

[@AureliusR]

Awesome information!

[@tybo09]

I laughed way harder than I should have at the bit about an aircraft full of flight recorders crashing. :) I love your teardown videos. I haven't got the foggiest idea what most of the bits that make up these things are (or what the do), but it is still cool to see them inside of items people encounter.

[@mikeselectricstuff]

Late 80s-early 90s I think. Stuff like this has lengthy approvals processes so you want to keep a design in produciton for as long as possible. Beacon will probably have been replaced since the recorder was new.

[@leolessa]

where did you got a flight data recorder ?

[@mikeselectricstuff]

Data cartridges record continuously in alternate directions - the 4-head setup suggests this is probably the case for this unit, so it can record and verify in both directions.

[@pepzi_]

Great teardown! I've been wanting one of these for years, but now that I know whats inside them, I guess I'll use something more commonly available as a door stopper :)

[@ZeedijkMike]

When does the engineers learn not to put on a "Do not open" label on equipment that should not be opened. Put a "Instructions inside" label instead. Great (and a little morbid) start to the video.

[@ncc74656m]

If you ever do pick one of these up to play with, especially older units with tapes, be quite careful. I was warned by a lawyer for a former employee of one manufacturer of these that they may contain asbestos as fireproofing material. The electronics are generally quite safe, but the tape side (which is usually its own compartment) is where the danger may lie.

[@Zizzily]

Having worked for Honeywell in the avionics division, in IT though not directly with avionics, I can say that you will see lots of avionics with bodgery on them. A lot of the lines aren't high volume, and even the ones that are, anything that's rejected from QC inspection goes through a "rework station" where they replace whatever components that have failed without having to try and remake the PCB.

[@MM0SDK]

Lol loved the intro.

[@mikeselectricstuff]

Flash is much more resistant to high temps than tape - if damage is so severe it can mechanically damage the tape it won't be in any shape to splice together. Flash could also distribute redundant data over multiple chips or boards easily.

[@cyrex686]

The best way to de-pot stuff I found is to just use a dremel with a wire brush attachment. It will eat right through the rubber, but leave components and the PCB intact.

[@Anvilshock]

Thanks!

[@mikeselectricstuff]

I suspect these may have been the result of early CAD. Right-angle traces aren't a big deal, but have more inductance and can have manufacturing issues at finer line widths

[@stumbling]

"OMG 700 planes have just gone down in the same spot!"

[@stemtuber]

Brilliant! The tape drive motor is probably external because it is dissipating a small but non-trivial amount of heat. Inside the insulated compartment, this would build up, reducing the recorder's time-temperature rating.

[@YQTFun]

Unless I'm mistaken, the majority of FDR manufacturers have facilities very near the airplane factories, also the chips on the pcb's turn a different color if a temperature is exceeded for a particular time, that tells the techs that the data is probably corrupt. There still are lots of tape recorders flying as well as the older style foil type, as well as the newer flash type, but with ever increasing number of planes with sat links, some of them are flowing data directly to the airlines.

[@Aussie50]

Love the intro :D You find the most unusual things to delve into Mike :D a complete one would make a great ornament in a workshop or living room :D

[@douro20]

The latest trend in flight recorders is the deployable type. They are much cheaper to manufacture because they don't have to be as well protected as a permanently mounted one- they are designed to be deployed from the aircraft before they go down. This also increases the likelihood of the recorder actually being found.

[@matthewrichardson828]

22:00 The extra wires going to the pressure sensor are likely for temperature compensation. Some of the EEPROMs are likely programmed with the compensation values. (Horner's Meathod data)

[@MysticalDork]

The flight recorder shipments are probably arranged to use a different brand of flight recorder or maybe have it or the ones being shipped out specially marked or designated somehow.

[@douro20]

I wouldn't be surprised if Dukane actually manufactured the transducer itself; they are a world leader in acoustic manufacturing technologies and one of the few makers of ultrasonic welders who makes their horns entirely in house, including the ceramics.

[@TheThore]

can you show this video to the inspectors of the MH17 flight recorder? I guess they have still trouble opening it...................

[@Max-x8e6l]

TheThore haha true !

[@tech4pros1]

in that hole there is probably a piece of intumescent material that expands significantly when it gets hot, sealing that hole up.

[@Muonium1]

The latest thought is that they should start moving to continuous data streaming from aircraft to land based recording facilities via some kind of TDRSS satellite link. I like the idea. No more worrying about recovering a data recorder in 8,000 feet of water in a Air France 447 type scenario anymore. Physical data recorders aboard the aircraft can be used as backups.

[@wisteela]

Fascinating stuff. Not something you get to see inside of everyday. Love the end thought.

[@mikeselectricstuff]

Older ones use metal foil to record mechanical traces on - there is a teardown of one of these online somewhere

[@SkyCharger001]

another reason for the motor to be outside: the belt is more likely to break, making it easier get the tape to stop during impact, making it easier for investigators to find the start/end of the loop

[@bikingmnviking3801]

+SkyCharger001 I was thinking it'd break once enough heat was created and to ensure it to stop recording. Just because you want circuitry to stop at a certain time, doesn't mean it always will -- think about that after 300gs or its underwater.

[@SkyCharger001]

+BikingMNViking: A. I never said it was a certainty, just that it's more likely. B. with flight-recorders of this kind the tape should be long enough for the difference between end-point and stopping-point to be relatively insignificant (IE: investigators only need to check 1/16th of the tape for the end/start-point instead of the entirety of it)

[@bikingmnviking3801]

SkyCharger001 When does thing turn on? All I was trying to point out is that you would want it to shut off in a catastrphic fire and having the belt exposed to the heat would ensure that. The belt might have a specific temp at which it fails.

[@SkyCharger001]

+BikingMNViking : perhaps it's easiest to say that a Flight-Recorder has multiple deliberate failure-modes.

[@bikingmnviking3801]

Probably, I've never googled any more details about how they work. I would just think one would want the most usage of the tape and after everyone is either too far from the mic to be heard over the roar of the fire or that everyone left near the recorder is dead so it'd be advantageous to have the belt melt off since there is obviously no reason to have it left running at this time. Without knowing what starts it up it may even be an overall event timing device -- I mean it can not record pitot tube data forever (today's new digital ones probably could and just loop over itself own memory) and I know that has been VERY helpful in some crashes -- one recently had the plane's pitot tube ice over and the autopilot pushed the power to max to try to increase airspeed which of course only iced up the pitot tube even more. The result was everyone died. I wish I could remember the flight number but what surprised me about it was that it was quite a modern aircraft but it was flying near some mountains as I recall. Interesting also to note during his gyro teardowns the bearings are nothing fancier than what is in my bicycle rather it is the devil in the details. They take plenty of care to balance the unit. (interesting balancing vid from Suburban Tool where they take a tour of remanufacturing a spool -- THEY even call in an expert to rebalance CNC mill heads that spin over 25k!) I'm sure they use wide-temp spec grease, too, because you loose 2 degrees F every 1k ft you are away from Earth. Aircraft have some of the best designing & engineering ever done on Earth, that's for sure. Lives in the balance.

[@PilotPlater]

Yes, it is very VERY expensive to certify hardware for aviation, especially for commercial aviation. It's far far cheaper to stay with slightly older hardware than to replace it.

[@faqbytes4875]

It's really cool just to see what these things are really made of, and gives a bit of insight to how they work as well.

[@opmike343]

Honeywell has a number of solid state FDR's on their website. They appear to be the same size externally (compatibility/integration?) but I assume the internal electronics are going to be smaller.

[@CassetteMaster]

Fascinating to see. I love the looks of military and similar spec electronics, the quality is so good, and is pleasing to the eye.

[@pepzi_]

Oh, does it rewind the tape when it's done? That will case some data loss. But I guess recording "backwards" wouldn't work since it would keep the old data and overwrite what just happened before the tape ended.

[@d3115uxor]

i wonder if you could locate another wheel that the reel-to-reel could possibly be reused for audio?

[@mikeselectricstuff]

Problem is it's hard to get interesting stuff at a decent price. Won an aircraft laser on ebay a while ago but the Ministry of Defence stepped in & stopped the seller shipping it. Bastards.

[@mikeselectricstuff]

I think it records in alternate directions, one track at a time

[@Byudda]

Did everyone watch this twice ! Great tear down Mike as usual.

[@lyntonr6188]

only twice ? lol

[@MarkTheMorose]

Fascinating to see inside, even if I know nothing about electronics.

[@0zaliz0]

Nice video! How do you get your hand on this stuff?

[@Jourei_]

A good point. Especially if all of the flight recorders have that underwater beacon fully operational... Good luck trying to find one needle of a stack of needles, that make a hell of a lot of noise...

[@helicoptered]

What are those lil round components like LED soldered flush to the board surface, they sorta clear sea through LED type things?

[@absenteeadvisor]

Thank you, sir. Excellent job of describing the components. I appreciate your sense of humor and your technical acumen. Cheers.

[@thomasleerriem6872]

Did I get the date code right on one of the IC's of the PCB stack inside: 25th week of 87? (seen at 11:34)

[@donpalmera]

How old was this thing? The AMD chips on there were really old tech.. but the expiry on the beacon was 2005 I think.. does the beacon have a really long life or is it older tech for a reason?

[@c2thew]

not sure how i stumbled on your video, but this is a very interesting channel you have here. keep up the good work!

[@markd8593]

as salt water is not shorted the beacon if you can measure the voltage of the battery through the case?

[@danivanon]

how would that ping help someone find it if you have to be so close to it to actually hear it with the transducer?

[@douro20]

I've depopulated a few conformal-coated PCBs in my time; it can be quite a challenge if you don't have a desoldering pump (I can't afford one!). The worst I've ever worked with was an ECU for a Nissan VG30DE V6 engine- I only managed to salvage a handful of components off of it because of the sheer thickness of the coating...

[@gregf9160]

Have you ever come across the really old steel wire recorders?

[@fortj3]

Where can I buy old flight recorders like this, and how much do they cost?

[@rocketman221projects]

It seems a bit strange that they would use flash. If it gets damaged everything is lost. If the tape gets damaged you can splice together the good parts and still get data from it.

[@alangrai]

Motor outside the fireproof case to isolate tapes from magntic field?

[@originalmianos]

I wonder how long it takes to rewind? What happens if there is a flight problem while it is rewinding?

[@k250014783]

This device is exactly what records data from the control systems and sensors on the plane. Why would it have pressure inputs and whatnot if it didn't? The voice recorder is usually a separate device, and in fact, data recorders came first.

[@stphinkle]

Any clue about what type of data gets recorded on that device? Might be interesting to trace out the pinout of some of the input ports and see what types of things the flight recorder actually records. I wondered if what gets recorded is analog or digital. Also, what type of equipment is needed to read such as recorder? A computer? Dedicated device? An insturment panel? Other?

[@FireDragonAnime]

Is that fluffy looking material behind the yellow shell asbestos?

[@stumbling]

All this military grade stuff is so pretty.

[@michaelthompson7217]

[sic] not military looks like ARINC 747 compliant FDR. Military grade parts just means environmentally resistant Real military grad would mean no FDR / shitty sd card in a palm pilot / ipod plugged USB into the cockpit

[@akimbomidget]

I think it would be wiser to have both. Tape can lose data, but they tend to preserve some data. While loss of data in flash memory is and all or nothing process (But is more sturdy). Keep one in tape, and one in flash mem.

[@stephenwilliams4501]

Very interesting, but you should have really been helping outside with the airplane crash....nice scope too, I'm still on cathode ray!!

[@SirArghPirate]

How do you get your hands on one of these? And how expensive is it?

[@Garganzuul]

How does the magnetic read/write head work?

[@buckstarchaser2376]

I suspect that by putting the drive motor outside of the tape protector, there is virtually no source of strong electromagnetic interference remaining in there. Besides that, the shell is meant to be a good thermal insulation barrier. If you put a motor inside, you'll then have to conjure a method of removing its heat, then you'd have to find a way for that mechanism to not allow heat back in in case of fire. It makes all kinds of sense to keep the motor out of there.

[@kevinolesik1500]

great dramatic beginning ... bravo ! nice shiney chipsets

[@TPJods]

Were the boards coated in varnish?

[@hydrolisk1792]

Okay I'm 44 seconds into the video and really want to know where you got that and if you know where I can locate some obsolute/surplus aircraft gear and instruments? Cheers!

[@lyntonr6188]

same place the rest of us get it , EBAY

[@omumafu6346]

Don't be a smartassel

[@RedRider2001]

That 8080 chip is a bit of a surprise, to me anyway. The Intel 8080 was made in 1974 I think and then however long it took AMD to reverse engineer it from there (it wasn't licenses at first). It's a surprise because it was still one the market as one of the more advanced chips in 1977.

[@markd8593]

why not use surface components? I think the components on the legs are much more vulnerable to shocks and overloads? (can rip them from the legs or break on board)

[@kwaaaa]

Problem with salt water is that it absorbs quite a bit of radio energy and passive RFID technology is range restrictive. This is probably why it uses a transducer to send the locating pings instead of a radio ping. Now, your idea isn't that far fetch though, because for people who ski, I recall that they do use a form of RFID beacon to location people in the event of an avalanche.

[@lzrbeam]

The last pressure sensor is a automotive type manifold pressure sensor.

[@JGunlimited]

Also why magnetic tape recording as opposed to SSD? SSD would likely take up less space and require less mechanical components...

[@SkyCharger001]

+JG SSD didn't exist in the days of THAT FDR

[@MoldyStir-Fry]

Those are the most beautiful circuit boards I have ever seen

[@Muonium1]

What kind of battery was that? Lithium Sulfate?

[@AK-uz4pi]

Any training available?

[@a.t8832]

Your a very smart person, youtube should be paying you for your input. Well done

[@JGunlimited]

The automatic captions are very useful! How do they do it?

[@freeebord]

Great teardown Mike - Have you considered doing some more videos on military grade equipment? I found your previous teardown on those random military boards really informative as to how much work goes into the development of high spec hardware.

[@Cruisey]

For all the people who are like "WER U GET DIS OMGWTFLOLBBQ" - it took me about five seconds to get from here to an eBay listing for a flight data recorder. If you have zero ingenuity or curiosity, please spare the rest of us your comment.

[@RizLazey]

Evelyn yet its illegal to sell these equipments

[@AureliusR]

@@RizLazey Not true at all. Your username suggests you're likely not an expert in the field...

[@Marineio]

Perhaps putting the motor inside the heat-proof case would cause the tape temperature to rise too much if the motor gives off a fair bit of heat? Other than that, size is probably the only other reason.

[@apprenticemart2]

I would guess that the motor is outside the case because the motor itself is a potential fire risk?

[@AureliusR]

I am very perplexed by the arrangement of the tape mechanism. As you pointed out, it would make a lot more sense for it to be an infinite loop tape. I have to assume that instead of using infinite loop, it records in one direction with one set of heads; then when it reaches the end of the tape, the optical sensor sees this and *instantly* switches the tape into the other direction using the other set of heads. This way the longest record time is achieved. The reason this seems likely to me is a) the volume of the actual record area is not big -- the tape size that could fit in there probably could barely do a few hours of record time. Even assuming they run it at a slower speed, like 3.23 ips, with a single audio mono track and three data tracks, I'd be surprised if it was able to record much beyond 2-3 hours. However, I suppose it's usually the last 30-45 mins of a flight that matters. Although the case of that jet flying across the US with all the passengers and pilot dead from oxygen deprivation comes to mind -- the flight recorder recorded over the beginning of the tape after takeoff, where the important events occurred. Despite this, they were able to conclude it was pilot error. You'd really think they would have accounted for incidents like this, and used bigger reels of infinite-loop tape...

[@Punky-Boy]

when the gps locater fals in the water its be activate but wil it activate when you dry it ?

[@deedubbs4412]

Interesting teardown, but its worth mentioning that you cant measure altitude inside of a pressurised aircraft. Maybe the pitot tube is meant to function in event of cabin depressurization?

[@splashman63]

+Dee Dubbs Flight Data recorders are mounted in unpressurized area of the aircraft, normally in the aft section fuselage or in the vertical stabilizer (tail) to increase it chance of surviving. The recorder does have it own independent pitot/static system.

[@AK-uz4pi]

Any available training??

[@superdau]

This is not your average tape recorder, that has (had) to keep up with the newest trends ;) . A device like this has to reliably work and meet specs. Almost every failure case has to be taken into account, design and testing that takes years (I guess). If you exchange parts especially core components like MCUs/CPUs you'd have to test and get certification all over again.

[@chrisdowling1997]

The outer layer doesn't look all too rugged? Surprised it doesn't get destroyed when dropped from 30,000ft!

[@deanmaessen]

always very interesting to watch your teardown videos. loved the beginning and ending.

[@network_king]

interesting. I figured it would be like a computer hard drive. wonder if the new ones are like SSD based. think be a lot less sensitive to shock, etc.

[@mikeissweet]

Excellent teardown, as usual. Very interesting to see. I was quite surprised to see all those bodge wires considering the rest of the design. Also, I wonder what keeps fire from entering through the slot for the belt and destroying the tape.

[@qwertyboy1234567899]

Do they still use tapes today?

[@TheJetSparrow]

Those first 2 pcbs you pulled out had right angle corners on the pcbs traces. I thought that was a big no-no.

[@DarenPage]

That's highly impressive for 6 layers, when was it made?

[@MrGerbilBrain]

Where the heck do you get this stuff? :O

Why are aircrafts using 115V, 400Hz?

[@jjak1990]

I really enjoy your videos! I'm glad i found your channel.

[@pedroochoa836]

where did you get that?? I want one

[@goyabee3200]

What do you use for hex editor?

[@Debraj1978]

I recommend this video for anybody who thinks himself/ herself as engineer. Thanks for the video.

[@erikdravn]

AWESOME video mate!!!! Where did you manage to find one of those beauties??? :)