Why is ONLY black-box (CVR and FDR) used in planes?


I apologize if I sound ignorant.

Why are there only CVR (cockpit voice recorder) and FDR (flight data recorder)? Also having something on the ground which receives information (both pilots’ talks and FDR’s all data) from the plane every second would make it unnecessary to search for CVRs and FDRs after crashes, right?

What do you think?

An important issue is bandwidth: it’s not practical to transmit the amount of data that the flight data recorder collects by any normal means.

I agree with Xema that for now bandwidth would be a problem.

Next would be the problems in receiving and storing such data. The Earth is a big place and there’s probably plenty of places where there would be radio outages and signal degradation even if they transmitted to satellites.


Bandwidth - there are something on the order of 20,000 heavy transports airborne at any given time.

Every 2 years (at most) there is reason to look at the data.

The infrastructure to capture every bit of info (I know how planes work, and still have no idea what all the data captured is) from every one of those planes and store it until the plane has cycled another hour after landing (a reasonable approximation of what would be on the FDR) would require a network almost as complex as the current International Air Traffic Control system - dedicated ground tracking and satellites over the polar routes.

Ain’t gonna happen until everybody on earth has a box in his pocket which can listen to airplanes, and the frequencies become discreet to 1/2 of one Khz,

At the current state of the art (which is ca. 1980), the cost to transmit data continuously from plane to ground is prohibitively expensive.

When we reach calendar 2040, when the state of the art becomes equivalent to 2010, we might have what the OP is suggesting.

I was watching the news last week and they showed real time flight data from airplanes in Africa.(I think). I’m pretty sure it was the Canadian company Flyht. They had a quick shot of engines from a plane. Pretty cool stuff.

“FLYHT’s basic product is known as the Automated Flight Information Reporting System. It transmits data via Iridium satellites”

Anyone know anything about this? Would seem to be a decent solution.

None of the answers in this thread so far have been wrong, but the best answer is a combination of the posts of Gatopescado and Musicat: the technology to do this already exists and it is the cost and complexity of upgrading the current infrastructure to support high bandwidth telemetry and satellite surveillance that prevents effective implementation. The FAA NextGen program will implement much of this functionality (aside from voice data recording) in the United States and territories; SESAR will do the same in Europe. However, both programs have been delayed by budget cuts and interoperability issues, and ICAO has no actual authority or mandate to declare a standard or force other nations to comply.

The bandwidth requirements for telemetry are actually quite modest compared to other satellite tracking and telemetry systems, and the biggest challenge (aside from flying a constellation of satellites in low orbit with sufficient coverage to track aircraft over all major flight lanes) is the handoff to ground receivers and other coordination activities near congested areas such as airports and flight corridors around flight hubs where bandwidth and interference issues may arise; the system will have to automatically manage the switch without compromising control. The standard data compression, encryption, and multiplexing methods methods used for satellite telephony and launch vehicle telemetry can be employed to reduce bandwidth requirements and verify data integrity.


i read on line about that, don’t have cite.

it would costs thousands of dollars for the data transmission for this case of hours of data. the system would only turn on when a serious event occurred. airlines would object to having it because of cost to install the system.

The Flyht solution is to equip the planes with the transmitting capability, but it only kicks into operation if there is an emergency on the plane, triggered either by pilot switching it on, or certain normal flight parameters are exceeded.

That’s not really a good system from a forensic standpoint. Many times the flight data recorder will indicate anomalous operating conditions prior to an actual problem being identified, in which case crucial information may be lacking. It is still useful from the standpoint of being able to immediate signal distress regardless of line of sight availability to a ground receiving station, but not a true solution to capturing full information. But again, with modern communications protocols and a comprehensive system including a dedicated satellite constellation (instead of leasing space from ORBCOMM or Iridium (the latter being primarily a voice carrier that is not really set up to handle high bandwidth single source telemetry) and handoff to ground receiving stations in congested lanes, the bandwidth considerations are not a fundamental problem.


I am reminded of one of the best WKRP episodes ever where a remote broadcast is taking place in a consumer electronics store, with the proprietor played by Hamilton Camp (RIP), and the DJ, by “Dr. Johnny Fever.” The proprietor is proud of his product line, state-of-the-art, expensive high fidelity equipment and is quite upset when Bucky Dornster, the radio station’s technician, knocks over a “Goering 2000 Turntable.”

But Bucky isn’t impressed. He points out that he has,* in his van*, a custom-designed hifi system that would blow the entire shop away and he probably built it from cheap, spare parts last weekend, just for kicks.

My point is that to a tech-nerd, a system to transmit copious quantities of data from all planes all the time seems simple and relatively cheap. “Heck, give me a solder gun and a pile of leftover parts, and I’ll whip one up over the weekend.”

But to the industry, which needs reliability, international standards, etc., this is not only a costly project, but subject to extensive cost analysis, planning, politics, lawyers and accountants. By the time everyone agrees on what to do, it will be obsolete and too expensive to consider, but they will implement it anyway.

Which is NextGen in a nutshell. A good idea, implemented in the worst possible manner, hampered by budget restrictions, poor focus, and so many cooks in the kitchen that anything that comes out in an actual food-like manner will be an unexpected delight regardless of how mediocre it may taste.