Another enthusiast question. I watch a lot of the National Geographic Channel's "Air Crash Investigation", for better or worse, and it seems accident investigators make tremendous use of the Cockpit Voice Recorder "CVR" and Flight Data Recorder "FDR" to determine the chain of events leading up to- or the root cause of an accident.

One of the more recent episodes of ACI (Season 12 Ep. 13) was about Air France 447, the worst disaster in French aviation history. That investigation spent two years and $50 million just locating the CVR and FDR which were ultimately found resting 4 kilometers beneath the mid-Atlantic. Even after the recovery, there were concerns one of the drives had failed.

That ACI episode also mentioned that the Airbus A330-203 in that accident came equipped with a system which periodically transmitted maintenance data to a remote Airbus location in Paris to alert ground crews of possible maintenance issues with inbound aircraft.

Given that Airbus already uses similar technology for maintenance data (and I think I recall hearing Boeing does too), I was wondering if either Airbus, Boeing, or the FAA, plan to facilitate or mandate that the CVR and FDR record to the cloud or a remote location either in lieu of or in addition to the physical devices installed in commercial aircraft. I would think this would be an accident investigator's dream come true, with almost instant access to vital investigative information, while drastically reducing instances of going without these crucial tools when the physical devices are unrecoverable.

So, does anyone in the know have any idea if there are plans for CVR and FDR data to be transmitted and recorded to the cloud or a remote location?

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    $\begingroup$ @pondlife I removed the tag airline-operations from this question because FDR's and CVR's are not specific to the airlines. (I have them in the airplane that I fly! ) $\endgroup$
    – Lnafziger
    Jan 19 '14 at 15:49
  • $\begingroup$ @Lnafziger Good point, ironically it's probably more practical - in purely technical terms - for a C172 driver to stream flight and maybe even voice data from his iPad than for an airliner to do it, for the reasons you've explained. $\endgroup$
    – Pondlife
    Jan 19 '14 at 16:22
  • $\begingroup$ Actually the BEA recommendations on that specific topic includes: "study the possibility of making it mandatory for airplanes performing public transport flights to regularly transmit basic flight parameters (for example position, altitude, speed, heading)". Many solutions were evaluated for their feasibility and cost by the working group. Solutions similar to the one you suggest have been studied but are not yet mature. See the linked report for additional details. $\endgroup$
    – mins
    Jan 30 '16 at 22:56
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    $\begingroup$ airtrafficmanagement.keypublishing.com/2019/02/08/… $\endgroup$ Feb 12 '19 at 15:33

The basic problem with transmitting CVR & FDR data to the ground from flight is the sheer amount of data that is generated by today's sophisticated airplanes. There are hundreds of parameters being recorded many times per second plus the voice channels. Today's airliners record 500 GB of data on each flight. Take this and multiply it by the thousands of airplanes that are in flight at any given moment, and you can see that there would need to be a lot of bandwidth available for all of it to be transmitted wirelessly. There would also need to be a world-wide standard developed and hardware deployed so that an airplane can transmit the data no matter where they are. Airplanes operating in remote locations would have to use satellites, which are relatively low speed and expensive to deploy/maintain/operate.

In short, it just isn't practical with today's technology.

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    $\begingroup$ All it would take is for Airbus or Boeing to try it out, possibly with low-fi recordings or only partial data inputs/parameters and the technology would improve. In the case of Air France 447 it would've saved two years and $50 million–that's pretty serious time and money. "Isn't practical" doesn't seem like a great justification for marginalizing like this. (That's not a personal attack on you, but lots of things seemed impractical at inception and were tried, improved upon, and have now evolved to be commonplace.) $\endgroup$
    – cfx
    Jan 19 '14 at 3:55
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    $\begingroup$ @cfx It costs a lot more than that to launch even one satellite, much less a world-wide system with the capacity to do this. (See: globalcomsatphone.com/hughesnet/satellite/costs.html). Trust me, there are a lot of people who are looking into this, and there was at least one study specifically on the Air France accident that focused on the feasibility of such a system. The technology just isn't there yet. They do already transmit some data, but to do it at the speed of the FDR can't be done yet, especially on oceanic routes. $\endgroup$
    – Lnafziger
    Jan 19 '14 at 4:09
  • $\begingroup$ That was more along the lines of my question. Is it being done or investigated, not whether it's feasible. Thanks for the follow up comment–that would probably make a better answer. $\endgroup$
    – cfx
    Jan 19 '14 at 4:24
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    $\begingroup$ Yesterday/today's events re Malaysia Airlines' missing 777-200 (cbsnews.com/news/…) echo those of the Air France flight I mentioned. Hope it doesn't take two years to find out what happened. Even minimal cloud recording of FDR and CVR would be helpful in cases like this. Thoughts and prayers with the families of those onboard. $\endgroup$
    – cfx
    Mar 8 '14 at 16:09
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    $\begingroup$ @cfx: Someone on board of MH370 apparently made conscious effort to stop even the data transmission that exists. If the aircraft transmitted more data, they would have stopped that transmission too anyway. $\endgroup$
    – Jan Hudec
    Jul 17 '14 at 12:52

Could we record everything to the cloud? No. For one thing, we just don't have the storage capability and communication bandwidth. Transmitting data from a plane travelling at mach 0.85 over the atlantic is no mean feat: we've managed it, but it isn't like a home fibre connection running at a steady 100Mbit/s or more.

Add in the fact that currently we aren't saturating the satellites right now... but if suddenly every plane was transmitting at full speed constantly, both the frequencies used, and the satellites themselves, would quickly be saturated. We would need a LOT of satellites and a much larger frequency band allocated to that transmission type.

Then there's storage: there are thousands of planes in the sky, recording several gigabytes of data per hour. Perhaps if we used a similar "keep 24 hours of data" strategy, this could be manageable.

On the other hand, we could, and probably should, transmit and record some data, or at least more data than we do now. At the very least, we should be able to transmit basic telemetry and control input positions, along with perhaps a little information regarding engine power settings etc. They wouldn't necessarily be up to the level of the Flight Data Recorder of Cockpit Voice Record information, but it would at least give us something to work with.

Since MH370, there's talk of ensuring we, at the very minimum, know the location of every aircraft in close to real time, so if nothing else we should be able to localise the search area faster in future.

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    $\begingroup$ I agree wholeheartedly, however there's the whole 'everything electrical has a fuse' issue, so that would/could have defeated the system for MH370. A possible solution might include no transmission until an anomaly is detected, then starting, say 5 minutes ago (from the FDR/CVR), start streaming all data until the situation is resolved or the device can no longer transmit. That would significantly reduce the amount of data to be transmitted, as only 'situations' would be transmitted. $\endgroup$
    – FreeMan
    Feb 25 '15 at 16:45
  • $\begingroup$ @freeman define anomaly? MH370 is a very unusual case - typically the aircraft hits something solid/close enough to solid (usually the ground or see) and then we have to find the recorder - in that case, there's no anomaly to detect. Admittedly it would have probably helped for MH370, but not for many others. $\endgroup$
    – Jon Story
    Oct 19 '15 at 15:39
  • $\begingroup$ Since this just bubbled to the top again- "anomaly" triggering probably wouldn't have helped for MH370 (fuses can be pulled). However, if there's an engine out, loss of pressurization, or any other mechanical failure that would cause any sort of alert in the cockpit (OK, maybe not a "toilet not flushing" warning), that could be considered an anomaly that would trigger the beginning of FDR/CVR transmission. For AF447, for example, if it had been transmitting from the moment the stall warning went off, the time spent looking for the FDR/CVR would have been saved. $\endgroup$
    – FreeMan
    May 26 '20 at 16:14

Commercial aircraft do transmit a limited amount of data via ACARS. This information can only be received line of sight, so if the aircraft is over the ocean the information will not be received (except by a ship that might be randomly listening).

The information on a flight data recorder is stored to a tape or other high-density storage and contains gigabytes of information. It would be impossible to transmit this much data via a normal radio due to insufficient bandwidth. You could potentially transmit this much data with a microwave link, but this would require a complicated satellite-based system. Military drones, like the Global Hawk, do make such transmissions (the big dome on top is the microwave antenna). Even if you equipped commercial aircraft with such bulky transmitters, you would need to launch thousands of new satellites to listen to and receive all the transmissions from the thousands of planes. So, while it may be technically possible, the cost and complexity of such a system is way beyond what is currently viable.

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    $\begingroup$ Wikipedia says that ACARS can also be transmitted via HF or satellite, in which case it could send from over the ocean. I thought that was the case with AF447. $\endgroup$ Mar 5 '15 at 22:42
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    $\begingroup$ Ships might be able to receive ADS-B if the right equipment were installed (currently ships have no reason to do this) - but how would ships intercept ACARS? isn't it directed at satellites when over ocean? $\endgroup$ Mar 26 '15 at 8:57

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