Realtime transmittal of black box data?

Why can’t commercial planes transmit flight data recorder and cockpit voice recorder data to a central hub somewhere in real time? Seems like that wouldn’t be too difficult, i bet one passenger’s cellphone reading cnn.com or whatever would transmit as much, if not more, data. Why do we need to find the black boxes, hope they didn’t get destroyed or lost at the bottom of the ocean, spend time reconstructing them all to get the hard data, when it could be uploaded to the airline’s headquarters (or someplace else, maybe to the NTSB) in real time?

We’re not talking about that much data… the voice recorder data is probably very low bitrate mp3, and the flight data recorder is probably a quarter the bitrate of that. Just guessing, I don’t know for sure. But it’s simple data… airspeed, altitude, etc. I bet 100kb/sec would be more than enough.

The bandwidth traffic might be extremely heavy.

But I agree with your proposal, if it is in *addition *to the current black boxes, not instead of. The current FDRs and CVRs can track an enormous quantity of data for detailed analysis. So, 24/7 transmission for rudimentary basic info, and the physical black boxes for detailed stuff.
But…how do you know hijackers or rogue pilots won’t just turn off this data transmission, like they do transponders?

Yea I don’t see any reason it has to replace the hard data in the physical recorders. I agree there should be a physical copy of it in the actual plane like there is now.

If there is a lot of data so that bandwidth would be a problem, it could transmit only the most important data. A 32kb/sec mp3 of the cockpit voice data would be more than enough. And I don’t even think you’d need that much for the rest of the flight data. I just don’t see bandwidth being a problem. Not for each individual plane. Maybe for every plane flying at one given time … but even that shouldn’t be a big deal. I keep thinking that one passenger’s cellphone is probably transmitting more data at any given time (or one in-air plane phone, whatever).

My gut tells me the reasons for not doing this are political (“Europe insists all the data be transmitted to France”) and/or financial (“it would cost too much to give every $30,000,000 plane a $2000 upgrade over the next 20 years”). I’d just like to know for sure. Makes me sad.

Transmitting the voice and flight data sounds like a good idea, if you assume the system will always work. But adding complexity means there are more ways for things to fail. Those recorders are at their most valuable after an accident; they need to work when everything else is broken.

There are rare cases, like that Malaysia Airlines 777, where we can’t find the black boxes and may never know what happened. If we transmit the data, there will be cases where the transmitter (or receiver, or whatever) fails and we’d wish we still had on-board data to recover from the wreckage. Unless you want airplanes to have both.

And even if MH370’s black boxes are found intact, chances are they won’t be of any use. They only record for a few hours(?), not enough to trace back to the most vital part of the flight; the diversion westward off course. Which is another flaw of the black boxes; not recording data for long enough.

Yea, having instant, continuous transmittal of data would be far superior to having to find the black boxes. After a crash we’d know instantly what happened. Just pull up the last few hours of data. Last few minutes even.

I just keep expecting to hear that some nuclear weapons arms limitation treaty between the US and USSR prevents commercial aircraft from transmitting data about itself, or some crap like that. Gotta be something really, really stupid like that (and of course if that were the case, the russians would insist on enforcing it). Or like, the flight data recorder manufacturing industry has lobbied against any real-time transmittal of flight data. Because the system we have now is so superior and safer - for the children. But we don’t even need to get rid of the flight data recorders, just have them transmit the data somewhere in real time. No no no, that would be a slippery slope and send the wrong message about the necessity of flight data recorders. Can’t have that.

It’s simply cost vs benefit. However, some airlines have real-time satellite transmission of some system data for maintenance purposes. Most don’t

Most modern aircraft in reasonable parts of the world have ACARS and ADS-B that report a subset of aircraft data via radio / radar response. This works close to airports but not over open sea.

The benefit of universal real-time logging is to track down some infinitesimal fraction of aircraft that have some upset that can’t be recovered from the wreckage. The cost is massive satellite channel charges that in almost all circumstances are not useful.

The aviation industry, or at least the safety/regulatory aspects of it, aren’t all that quick to embrace new ideas. I don’t think that’s automatically a bad thing. What we’ve got works pretty damn well. I don’t think anyone wants to change it until they’re damn sure that the new system will work better.

There was a crash several years ago (TWA flight 800, I believe) that was eventually attributed to a pump generating a spark in a near-empty fuel tank, and igniting the vapor within. I heard it suggested at the time that planes should carry nitrogen on board and feed that into the tanks so there can’t be an explosive fuel/air mixture. Yeah, that’s fine, until a nitrogen tank bursts and causes a crash.

It’s not enough to just sound like a good idea. This is gonna be on every plane, everywhere, and it has to work all the time. Hardened cockpit doors sounded like a good idea.

It is only the CVR that has a two hour recording time, the FDR is around 30 hours and would have the entire flight.

Data is already being transmitted: Rolls Royce and other engine manufacturers monitor their engines in real time. It’s not continuous but sent in bursts.

I can see no reason why cockpit data should not be transmitted in the same way.

Some high end cars do the same thing.

Nitrogen flooding to prevent fuel tank fires is a pretty old idea, i remember how that was used on aircraft carriers during WWII. I agree the system we have works well… until it doesn’t. Seems a lot of people in the aviation industry say we’ve been very lucky so far, especially with respect to air traffic control. Most don’t even have modern radar.

On preview I see a bunch of folks have already chimed in this morning while I was typing. So some of this is redundant.
There have been industry discussions about something like the OP proposes. Or at least a “distress mode” which would start transmitting data when things started getting weird / dangerous.

The essential point and this applies to all the threads on all aviation events any time is that there’s only so much “budget” for adding safety to the system. I put “budget” in quotes, because I’m not just talking about money. There’s only so much bandwidth available in the RF spectrum. There’s only so much space in the avionics compartments to add new boxes. There’s only so much engineering talent & regulation writing ability and international cooperation, and … to go around.

And every time some talking head on TV starts a campaign to “fix” some perceived problem that’s pretty much a one-in-a-million event, resources are diverted from the things which will actually, demonstrably, save lives by preventing the “almost accidents” that happen every day.

Had MH370 had 100% real-time CVR/FDR download & 100% real-time position tracking the exact same thing would have happened to those folks. Nobody would have lived or died one second differently than how it really happened. The only thing that would be different today is that a billion people’s media-fed morbid curiosity would be a little more satisfied, and the CTers would have a head start on inventing their own competing version(s) of events.

The industry spends a very big “budget” every year on the things which do enhance statistical safety. It’s a very big system, with insane reliability standards and massive needs for backwards compatibility and universal international buy-in. So things move slowly.

For many proposed improvements, we’re already dealing with a system with failure rates down in the 1 in 10 million bracket. When things work that well, there are a lot more ways to introduce an unexpected bad consequence than to introduce an improvement. Doctors may have adopted it first, but “First do no harm” is a good motto for this process too.

But the real action is in the “almost accidents”. Right now, today, every day every aspect of most flights is being recorded onboard. Hundreds of megabytes per hour of data. On the newest jets its more like a couple gigabytes per hour. And all of it is downloaded a few days later while the jet is parked and later dug through looking for anomalies. Both crew performance and aircraft mechanical issues.

Out of these tens of thousands of flights per day per aircraft type and per company, patterns emerge. Every driver knows of that one nearby bad intersection where car accidents seem more frequent and you yourself have had a couple close calls. Aviation is now so safe we don’t have enough accidents to use them as a good guide to what *really *needs fixing. But we can now watch the “close calls” and direct resources to addressing them. Because they are what *does *need fixing.

It’s been a decade since we had the last US collision between an aircraft on a runway and something or someone that shouldn’t have been there. But right now there is a HUGE effort to adjust procedures, equipment, and mindset nation- and world-wide to reduce the frequency of close calls, which had been high & rising from, say, 2005-2010. Billions is being spent on ATC equipment aimed specifically at this threat and major engineering is ongoing on new generation cockpit tools to also reduce the risk. Meantime many procedures, some subtle and some pretty significant have been put in place to add more layers of backup & error avoidance to this safety concern.

But since nobody has been killed, CNN and therefore you, are 100% unaware of this effort. But it is bearing fruit and the so called “runway incursion” rate is dropping fast at most locations.

There are still some hard cases to fix. Chicago O’Hare is about 2/3rds through a multi-decade multi-Billion dollar effort to build new runways and taxiways in a less collision-prone layout compared to the 1940s-shaped reality it is today. Between buying land, getting suburbs to accept noise where it wasn’t before and all the rest, this isn’t easy.

Boston Logan is next. It’ll be 10 years before we get through the politics. Oddly, one of the biggest objections locals have is that since nobody is dying, it ain’t broke so it doesn’t need fixing. It’s hard to convince a hostile audience that reducing the error rate from one in 5,000 to one in 50,000 is worth them having jets directly overhead every 2 minutes UFN. But that reduced error rate converts into a few statistical lives saved every decade.
That’s the reality of how aviation safety proceeds. I’d never claim, and neither would the experts, that every dollar is always spent on the 100% closest snake and with god-like omniscient wisdom. But a lot of good people are putting a lot of serious thoughtful non-political, non-kneejerk effort into it.

And the results are paying off in myriad ways you don’t see when you don’t crash. But we see them all, because we’re doing them all.

An oddity is that as we wring out the last few thousandths of a percent of systemic predictable risk (no exaggeration), what’s left are the bolt-from-the-blue events. The next aircraft to go down may well be hit by a meteor. And we’ll be here on the Dope debating how to meteor-proof airliners or develop a real-time meteor reentry detection and warning system, complete with a planet-wide grid of instant 100% reliable secure communications.

Ref some other folks’ comments:

Nitrogen fuel tank ullage inerting is now required on new airplanes. And is being retrofitted into some older ones. In 20ish years practically all airliners except the rattiest leftover junk in the Third World will have it. Which will probably be before the next fuel tank explosion occurs.

As well there are procedural changes and wiring & equipment changes already done years ago to many aircraft types to reduce the likelihood.

In other words, the “lessons” of TWA 800 are in fact being addressed. The last person to die of an airliner fuel tank explosion (*ex *missiles, etc) has probably already died.

But since all of this is happening outside the attention span of the public and the media, nobody knows about it.

It’s worth noting that transmitting real time data isn’t really like someone having a cell phone turned on. As pointed out a few times above, many planes fly outside of cell phone signals, so we would have to have a satellite network available to receive the data. Solvable, and partially in use today…but comparing it to cell phone networks is only superficially accurate.

I agree with just about everything you said in that well-written and thought out post, but wanted to expand on this. Depending on what actually happened to MH370, there may be something to learn and improve to prevent a future accident. It’s possible that it’s something simple, or relatively inexpensive. So there can be a benefit to knowing. I agree that we’d need to look at the cost involved, though.

I did not know that; learn something new every day here. But it seems like you also confirmed my larger point, that you don’t make a change like that until you believe that it won’t add more problems than it fixes.

Can you absolutely, 100%, guarantee reception?

What about a digital CVR that could store more data and a transponder you cannot turn off?

What about an electronic device that is causing a fire and you cannot turn it off? What about a transponder that can’t be turned off, and at airports, with all planes transmitting at once, the traffic is too much to bear? What about a transponder that can’t be turned off, and is going haywire, interfering with other communications or navigation?

Every solution has a drawback.

Why is there a mindset that such a system has to be 100% reliable and 100% universally accepted and installed in every single plane? Can’t they just go for the low-hanging fruit first?

Some airlines/planes already have onboard wifi via satellite, even as they cross oceans. Can’t you just stick a slightly more developed MP3 recorder somewhere on the plane and have it transmit over that? Maybe it’s not vetted to the highest safety standards ever, but neither are the myriad electronic devices that passengers bring on board every day. An iPod has yet to crash a plane and is more than capable of sending data in real-time. Maybe this is only viable for those airlines that have onboard internet. Maybe it’ll only be 80% reliable. But isn’t that better than getting no data at all when a plane goes down? It’s like the engines – apparently some components already do some wireless communication on their own. Can’t be that hard to throw another one on there. If there’s enough satellite bandwidth for passengers to make calls on those seatback phones and check Facebook on a flight, surely they can send a stream of low-quality voice and text logs.

(Not to be snarky. I just don’t understand the difficulty of this problem. What is it that makes this so much harder to implement than, say, some cars having OnStar and other cars not having it?)

It’s late & I’m very tired so this’ll be quick. Any brusqueness is inadvertent.

Absolutely 100% of each aspect of each piece of equipment on board the aircraft MUST be approved by the FAA. Each nut, bolt, and screw is made of provably good metal with a paper trail pedigree going back to the mine. Ditto each minor electronic component. Every aspect of all the engineering is also examined and approved. And 100% of everything has to be tested to the nth degree.

And the FAA and the EU-equivalent agency have to agree first what designs they’re going to bless. No equipment manufacturer wants to get halfway done with development only to find the EU & FAA want to do things in mutually incompatible ways.

Nobody invests this kind of effort on half thought through throw-it-at-the-wall type designs. And everything has to be compatible with everything else. Not just designed to be compatible, but proven through testing to be compatible. If the FAA had its way, all personal electronic devices would be banned from pockets, purses, and carry-ons and inspected in all checked luggage to ensure the batteries are removed. Congress overrode that impulse.

It is very hard for somebody used to consumer products to comprehend just how regulated and how over-engineered things are. Which is why we have gross failure rates down in the 1 in 10 to 100 million range.

Which is also why a minor modification to a jet to add something the size of a car stereo costs easily $200K per jet. Not including lost productivity.