Black Boxes and Coffin Corners

As searchers recover more wreckage from the Air France jetliner that crashed into the Atlantic last week, Miles O’Brien reports on the perils the jet faced as it flew headlong to its doom in a gauntlet of equatorial thunderstorms. In an interview with BoingBoing TV, O’Brien wonders why jets don’t transmit telemetry data all the time, moving the black box from the back of an aircraft, where it could be lost, crushed or incinerated, to computers safely on the ground. Any ideas, readers? [%comments]


I assume it's because the transmission can be cut off by accident especially when something goes terribly wrong (like a crash), which is when you need it the most.


Not that I'm an expert on air travel but perhaps black boxes are clearer when reading two voices such as the pilots and the co-pilot. Also, there is always instances where airplanes when crashing lose all electronic singles, so transmitted data might be lost as the plain is in free fall.


My first guess would be that there are security concerns. Second guess would be that implementation costs (in terms of money and difficulties to overcome) would outweigh perceived benefits.


Why not... do both?

Why is this an either/or situation?


It's possible that, since most jets were designed years or decades ago, the systems haven't been updated yet to take advantage of the advances in bandwidth and storage capacity needed to transmit that volume of data.

And the black box remains necessary, since a failure in the communications or electrical systems would prevent telemetry information from getting out.

Even so, I feel like it makes little sense not to do this. The expense would be minimal, since the communications and recording equipment is essentially already present. And I there's a strong incentive for both airlines and manufacturers to stay on top of these problems.

Eric M. Jones

First; a lot of information from the plane is transmitted routinely, but not in all cases in all places.

Second; the cockpit communication between the pilots is only stored in the blackbox, since the pilots really don't want every private converstaion and word "on the air". After 20 minutes or so this information is erased (there are various standards for this).

Third; black box information is valuable since it contains information until impact. The VHF radios aircraft use are "line of sight", and there is poor transmission at low altitudes. Typically aircraft also have emergency locator beacons monitored by satellites that transmit upon impact.

Fourth; It could be done with a fleet of satellites and/or ground stations connected by internet. These things are changing all the time. This technology is always on the move, so is a pretty good idea.


It's trivial, Watson.. (-:

Black boxes date back to the middle of last century. Back then there were no computers, remember? And extensive transmission of bulk quantities of data also was not possible. So my guess is that we are simply continuing to live with an old technology. To install a new one would be very costly and only reasonable to do either on all planes or none. Also that installation would require ground reception of all this data - can you even imagine there are tens of thousands of airplanes up in the skies at any given moment that would be transmitting all the time.


My guess is that the Airlines are not too interested in doing this. As mentioned above, both black box and transmission of telemetric data should be done. Security concerns can be alleviated by doing a secure/encrypted transmission. Cost of implementing this should not be too much. However, Airlines do not like spending money so even a small implementation cost can be prohibitive to them. Besides, all that data getting into a database can lead to interesting reporting which if leaked might seem to indicate the dangers of flying an airplane. Plane crashes usually incriminate the airlines .. so they won't have a good incentive to implement something which makes this incrimination all the more easy.
A regulating body (FAA ..) should force this implementation. Telemetric data in a central database can probably reveal a wealth of information which can be good for safety of the airlines.


Perhaps because the cost of outfitting the whole fleet with satellite transceivers far outweighs the tiny benefit of knowing exactly which storm knocked a given plane down.


Why not both? In this case, the telemetry data right up to the crash or break-up point would be immensely helpful.

But I agree it's probably a cost/benefit issue. If it only helps in 1% of crashes, outfitting thousands of planes may not be deemed worthwhile.


There are aviation people advocating this:


The reason is, in fact, communications. My understanding is that black boxes are hard-wired to the instruments, and last right up until the plane breaks apart. And as for crushing and incineration, that doesn't happen. They're very sturdy. Losing them is the bigger problem.


All I had to do was search for "black boxes transmit information store" (first try) to retrieve news articles from reputable sources that covered at least five reasons:
- Data transmission is less reliable and/or harder to ensure that it would be reliable under all circumstances
- Current transmission capacity may not be available (tons of data)
- Satellite bandwidth is expensive
- The way the data must be treated is different so it would require new software and updating many systems
- Pilots are concerned about privacy

I guess it still all comes down to cost vs. benefit, but there are certainly a lot of costs when the black boxes have only not been found 3 times, not to mention the low overall rate of needing them in the first place.


Real-time transmission would be technically challenging and quite expensive.

From a Q&A on the Washington Post website yesterday:

"Why do we still use black boxes in this day and age? Can we not relay real-time information from the cockpit to a remote server? Please advise."

"R. John Hansman: The amount of data is very large (400 parameters some of which are recorded 30 times a second). It is technically difficult and expensive to send all that data in real time, particularly from remote regions such as the oceans "


maybe the same "reasoning" that banned cell phones....?


Airlines are historially loathe to add costs, including those dealing with safety, and they would bear the brunt of any upgrade to provide real time telemetry.

And in one sense they have a point: given the billions of passenger miles safely flown per accident, the storage required for all the non-useful data would be a major factor.

An alternative might be to make the locator "pingers" more robust and longer lasting, say two months, with a stronger signal, detectable up to five miles in water. That would give responders a much better chance of locating FDRs and CVRs ("black boxes"), with only very minimal changes in actual aircraft design, if any, to accomdate them. The government could help with costs of this retrofit.

lloyd alter

I asked my nephew the computer engineer and he told me "bandwidth. In the middle of the ocean it all has to bounce off a sattelite, you have to be able to aim your antenna toward the sattelite (try that in the middle of a thunderstorm"), sattelite uplinks are lousy in the rain and they couldn't handle all the traffic"


Both should be done. Here are some ideas:

As pointed out above, real-time transmission can be challneging, that's why the black box is needed as a backup. Also the system can be designed so that if there is a problem with transmisstion, the information can be stored in the black box or in some temporaty memory and when the wireless link is re-established, everyting not uploaded to the moment will be batch syncronized with the ground master storage. The link does not have to be with a ground dispatch center as well. Bad weather and terrain can influence reception from the ground. It is much better to use comm satellites, which can safely transmit the signal to its final destination.

I am sure all of this is doable and technicaly possible today. The reason why this is not happening today is cost. Noone wants to invest in a new system, which does not directly generate returns. And if this is left in the hands of the air carriers, I doubt it will be done soon. It has to happen top-down - governments, international alliances, etc. should institute the change.

Another concern can be security. The radio signal can be intercepted and decoded. This way terrorist groups, for example, can obtain valuable information on how the flights are running.



Here is a quote in answer to your question from the lede blog last week

While that quantity of data would no doubt be useful, my colleague Ms. Negroni writes to point out that this "would require great bandwidth and storage capacity to record all the hundreds of thousands of event-less daily flights. Someday, I have no doubt this information will be transmitted to ground rather than be collected on the aircraft on flight data recorders, but that's why we're not there yet."

Seems if convenience stores can use live cameras to monitor criminal activity, someone should find a way to monitor live flight activity.



I guess you are right Jones. In this case of flight 447 also, the big problem is not that the black box has been crushed out of use. The problem is that we are not able to locate where exactly it is lying
May be the best solution lies in embedding some kind of powerful GPS tracker so that the location is traceable all the time