As they continue searching for the EgyptAir black boxes, I’m wondering why they aren’t encased in something that would float to the surface. Granted, they would float only if torn free from the rest of the wreckage, but it seems that would happen sometimes. Wouldn’t they be easier to locate on the surface? Or do they want the boxes to stay in one place instead of drifting?
They have to be encased in something hard so they survive the crash. Such hard cases are made of materials (like steel) that are heavy. So they don’t float.
If you encased them in some kind of foam, it would have to be quite large to ensure that the whole package would float. That would make it hard to find an appropriate place on a plane for such a large item, when designers try to cut out every bit of wasted space on a plane.
Also, putting a large amount of foam around it, covering all the cables going into it, would make it even less likely to come free in a crash. So the end result would be an additional expense, wasted space, and only very rarely easier to find than current black boxes. Not worth it.
They will soon at least on some larger Airbus aircraft that routinely fly over the ocean.
*"Paris (AFP) - Long-haul Airbus A350 and A380 passengers jets will soon come equipped with ejectable black boxes that can float, making them easier to find in an air crash at sea, aviation sources said Monday.
“At the end of last year Airbus got the green light from EASA (European Air Security Agency) to work on the necessary modifications to its planes in order to install these new black boxes in the rear of the planes,” one of the sources told AFP."*
The reason that commercial airliners haven’t had them so far is because crashes into deep water have been viewed as low probability events (and still are despite some notable ones in the past few years). You can’t depend on them to just break free on their own in the event of an ocean crash either. It requires a sophisticated ejection system that is not cheap and the engineering just wasn’t there until it became a public priority. Don’t expect them on all airliners anytime soon however. Installation requires aircraft modifications to make room for the new systems and that is not a quick process for U.S. based aircraft and may never pass a cost/benefit analysis for most airliners.
Tangent, and maybe stupid question: why is the black box info stored on board the plane in the first place? Why not download it to the ground (if necessary, via satellite link)?
That would be a nice supplement to the flight recorders, and there already is a certain amount of data streamed for commercial reasons, but you need them recording for as long as possible, the satellite link might be lost before an onboard black box had stopped recording, so it shouldn’t replace an on board recorder.
“Black boxes” aren’t just one device. They consist of a Flight Data Recorder and a Cockpit Voice Recorder that run on an infinite loop that stops and preserves the detailed flight information and cockpit sounds respectively in the event of a crash. It is theoretically possible but not practical to transmit, receive and store all of that information in real-time. You would need a very large satellite network receiving all of that data for every commercial flight in the world all of the time. The satellite would then have to transmit it back to ground stations where it would be archived because the storage requirements are immense. The network would be capturing data for many thousands of aircraft worldwide at any given time 24/7/365 for decades and the vast majority of that data would be useless.
The most commonly useful flight data is tracked and stored but it comes from radar stations and ATC communications. That is usually enough information but not always because the only very rough coverage extends over the open ocean. That fact created the complexities associated with Air France 447 that crashed en route from Brazil back to France and Malaysia Airlines 370 that simply went missing and still hasn’t been found.
I am not an aerospace engineer but it seems to me that people are overthinking this problem. The issue isn’t with the “black boxes”. They are engineered extremely well already and can last even in the deep ocean for years. It is a matter of finding them in the first place. You don’t need to have the black boxes themselves float to do that. Instead, you could have a much smaller emergency locator beacon that transmits a signal to tell searchers where the plane is in the first place. Those already exist in many forms and can be small enough to be externally mounted so that they wouldn’t require nearly as much retrofitting to the plane. Once they actually know where the plane is, investigators can pull up what’s left of the plane and the black boxes just like they have to do anyway.
Nothing needs to be changed. The technology is already in place. Make it mandatory that aircraft transmit their location via Satellite while over large bodies of water.
This. It’s already possible, but the airlines just don’t want to spend the money.
To what? Communication satellites aren’t over large bodies of water; they are located where there are people who want to talk to each other, which is mostly on land masses.
With what? Planes aren’t equipped with satellite antennas on top of them, that are motorized to keep them aimed at the closest satellite. That would be pretty expensive to add, and would greatly increase air resistance & fuel consumption for the planes. I can’t see any airlines doing this.
And for what? Is this that big a problem, anyway? All those passengers are dead, so what does it matter? Seems like a solution in search of a problem.
How about a steel box INSIDE of a steel box with an air space around the inner box. The inner box would be “suspended” with bolts of some kind or a metal honeycombed material. The point is there would be a lot of AIR inside of the container so it would float.
Or how about encasing the box in some kind of flotation device that opens on impact, so when it hits the water, a big bright bubble-like “life raft”-ish thing opens around it?
In past discussions like this, I’ve suggested why not just continuously stream data via satellite. But if that’s not feasible for some reason, why not some kind of triggering mechanism/cue that begins to stream data when an alarm goes off like the one that detected smoke on board. So during routine, uneventful flights the regular black box would do its thing, but as soon as any trouble is detected data would automatically be streamed OR the pilot could trigger the streaming when s/he detects an imminent disaster.
There’s got to be a better way than a box that sinks like an anvil to the bottom of the ocean. We have the technology.
Even if the box itself can be made light enough to float, it’s got to be attached to the aircraft somewhere. How do you install it in an aircraft and make sure that it floats away from the rest of the aircraft in case of an accident??
Also, imagine if some fisherman or other unrelated sailors find and take your floating black box home.
But think of how often there’s a crash and the news mentions ‘all communications were lost X minutes/hours before the plane disappeared’.
Just going with the hypothetical here, I’d think explosive bolts would work pretty well. The next trick would be getting the black box free of the wreckage.
Personally, I’d be surprised if that was the case.
Also, as for it floating, as long as it’s big enough to be buoyant, it shouldn’t matter what it’s made out of. Cargo ships full of containers float just fine. A plane’s black box, encased in a water tight case (of whatever material it needs to be in), should float up to the surface just fine if the wreckage doesn’t hold it back, but at least it would have a fighting chance.
INMARSAT coverage. Oceanic regions have plenty of coverage, the only bits that don’t have coverage are close to the poles.
Sat-phones are common on airliners and other aircraft. Ever wondered how wifi works on a plane? Satellite antenna on an aircraft. Once you know what they look like you’ll realise that whole fleets of aircraft have them.
It matters because we need to learn what happened so we can try not to let it happen again. Aviation is relatively safe because we go to great lengths to work out why crashes occur. I agree to some extent that it is a solution in search of a problem. It is very rare to not retrieve the flight data recorders. The system currently in place is adequate, so expect any improvements to come slowly and only once it is cost effective.
By this logic, why investigate crashes at all?
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Tangent, and maybe stupid question: why is the black box info stored on board the plane in the first place? Why not download it to the ground (if necessary, via satellite link)?
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There is a system called ACARS (Aircraft Communications Addressing and Reporting System) that does transmit some data throughout a flight, but there is a tradeoff to be made in sending a few occasional bits of data reliably on a low-bandwidth transmission that can work nearly anywhere, or streaming lots of data on a high-bandwidth signal that will be technologically expensive, difficult, and fragile and unlikely to work away from land-based radio stations.
For the most part, ACARS is used for accounting purposes (it automatically signals events like cabin doors closing, takeoff, landing, etc. more for payroll purposes than anything else) and maintenance notes like “#2 engine is running a little hot,” but it has had some uses in crashes such as 2009’s Air France 447 crash, where the airplane transmitted a “disagree” message which meant the computer was getting conflicting air speed indications from various sensors and some advisory messages that the autopilot had disengaged and the computer was operating in what Airbus calls alternate law mode, aka “Help, Mr. Wizard!” as the computer has pretty much lost all sense what’s happening and was unable to provide its normal protections against stalls, overspeed, etc.
Worth noting, airplanes already commonly carry emergency locator beacons. They are typically designed to begin transmitting if subjected to sudden changes in motion (such as from a plane hitting the ground). There are older ones that transmit on VHF (no longer authorized) and newer ones that transmit on UHF. The old VHF ones would just broadcast to whoever could receive them, and the new UHF ones are designed specifically with satellites in orbit that would pick up the signal and sound an alarm.
The reliability of these varies, not least of all because they are sometimes damaged due to being in a plane crash, or due to the plane crashing in places which make radio transmission and reception difficult (like mountains and valleys and the bottom of the ocean). Sometimes the equipment just isn’t maintained properly. NASA has been doing some research (by dropping old Cessnas from a crane) both to study the sort of damage planes suffer during crashes in a variety of terrain and to figure out how to improve the transmitters.
Maybe include some high-volume, bright orange dye packs packed onto the ends of the boxes.
If the crash is normal (land), they do nothing. In water, they create a bright plume for a couple of weeks.
The packing could even have inert stuff dissolving for the first 3 days (while people figure out the likely location) then the dye starts dissolving.
Cheap, easy, light weight.
Perhaps, though aside from any environmental concerns that for the purpose of discussion I presume we would have resolved before employing these dye packs, there is the practical issue of the volume of water in question. The oceans are very big, and depending on where you are and how deep you end up, the water is very cold. The first means the dye will be more diffused, the latter means the dye packs might not dissolve at all since cold water doesn’t dissolve as effectively.
Maybe an audio beacon to supplement any other location aids? There are all manner of submarines and sonar arrays and such in various parts of the ocean.
Following up on my previous post about radio beacons: I have no idea if the UHF Emergency Locator Transmitter beacons used on civil aircraft in the US work with the aforementioned satellites to trigger automatic alerts if they are not in the United States. The system might not be deployed over open water or other countries, I honestly don’t know and it’s something I might look up.
The 406 MHz beacons work world wide.