As I understand, there are two black boxes on-board an aircraft. One black box, the Cockpit Voice Recorder holds the cockpit conversations and the other, the Flight Data Recorder holds essential flight parameters.
There are a couple of reasons that I can think of off of the top of my head:
There are different regulations covering when each of the boxes is required. Some aircraft only require a CVR while others require both. With them in different boxes, they can be installed in whatever combination is necessary.
They require connections to different systems in the aircraft, and requiring them both to connect to all systems would result in quite a bit of additional wiring. It would also expose each box to a potential catastrophic electrical event (voltage spike) from any of the connected systems, potentially damaging both boxes at the same time.
There is already some added redundancy by them being in different boxes. Even if one fails or is is badly damaged, there would probably be data available on the other one anyway.
As Farhan pointed out, there are already some units capable of recording all data at once, but since the regulations only require one unit there is no added redundancy. For aircraft that are required to have both a CVR amd a FDR it could be a great option!
Similar to Lnafziger, here is what I can think of:
The number of cases where your suggestion would actually benefit investigation is not very many. In crashes that damage the recorders too much, making the recorders larger and more complex would probably not help. There have been many cases where the recorders didn't work properly or at all, so giving more functions to each box makes this more likely to occur more often.
Here is a list of unrecovered flight recorders. Considering the time it spans, there are not many, and in some cases, neither recorder was recovered.
I'll see if I can find any references for the cases where they were recovered but contained no useful data.
In my opinion, I think that whatever is present in one black box also will often tell the other half of the story as well.
For instance, if the airspeed indicators are unreliable, the CVR will pick it up by the pilot's talking, even if the FDR may be lost or destroyed, which will point investigators in the right direction how to continue the investigation.
In other words, I'd imagine there's a bit of indirect redundancy by two devices.
However, many aircraft have a quick access recorder which although not armoured will give much the same stuff as a FDR. If I'm not wrong, Flight Data Recorders are mostly non-mechanical devices and are tested annually, so they are kept reliable.
Black Box(s) is a misnomer, you have correctly mentioned their actual names.
Why are the two black boxes holding separate data?
They have different purposes.
Flight data recorder: This is an electronic device employed to record any instructions sent to any electronic systems on an aircraft. It is a device used to record specific aircraft performance parameters.
Cockpit voice recorder: This device is used to record the audio environment in the flight deck of an aircraft for the purpose of investigation of accidents and incidents.
Why don't black boxes hold copies of both the FDR and the CVR data for extra redundancy?
Since they record different data, they are different. They are built different.
Are there any technical reasons for why this isn't possible or hasn't been attempted yet?
It has certainly been attempted.
Is there any benefit of having the CVR and FDR in separate boxes?
Probably the reason is that different teams investigate the data obtained from them as they have to recreate the scenario before the accident.
CVR: Due to the highly sensitive nature of the verbal communications inside the cockpit, Congress has required that the Safety Board not release any part of a CVR tape recording. Because of this sensitivity, a high degree of security is provided for the CVR tape and its transcript. The content and timing of release of the written transcript are strictly regulated.
FDR: Newly manufactured aircraft must monitor at least twenty eight important parameters such as time, altitude, airspeed, heading, and aircraft attitude. In addition, some FDRs can record the status of more than 300 other in-flight characteristics that can aid in the investigation. The items monitored can be anything from flap position to auto-pilot mode or even smoke alarms.
As I understand, there are two black boxes on-board an aircraft. One black box, the Cockpit Voice Recorder holds the cockpit conversations and the other, the Flight Data Recorder holds essential flight parameters. But why are the two black boxes holding separate data? Why don't both black boxes hold copies of both the FDR and the CVR data for extra redundancy in case the other box goes missing or is completely damaged by the crash? Are there any technical reasons for why this isn't possible or hasn't been attempted yet? Is there any benefit of having the CVR and FDR in separate boxes?
Why is it that black boxes don't float? From what I gather the answer is: So they will not float away from a water crash site. The ping can be heard underwater with sonar. Finding the ping, finds the site. But why not have two black boxes one that floats and one that stays with the aircraft? That way if a plane is lost at sea, if we find the black box floating, we could use the data to find the other black box and the crash site. Plus the benefits of having a redundancy are enormous.
Can an FDR on a Boeing 777 be interfered with or vandalised during flight? If this has happened on MH370 then the black boxes may not yield any data if found.
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... 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... have any idea if there are plans for CVR and FDR data to be transmitted and recorded to the cloud or a remote location?
Do the manufacturers who build airplanes use their own "black boxes" in the planes, or are there companies whose sole purpose is to develop black boxes? For example, in 2010 in the Airblue Flight 202 incident, the black box had to be sent to Germany for data recovery: He stated that the box would be examined by "foreign experts" in Germany or France as Pakistan does not possess the equipment to decode the flight recorders. He also stated that the process of extracting information may take six months to a year. The Pakistani authorities decided to send the CVR and FDR
. This is just so we can find plane crashes in the sea when we don't know precisely where they went down (and to get basic data when the black boxes are too deep to get to immediately). Malaysian flight...Without getting into the mess of redesigning existing Flight Data Recorders, I have a simple proposal that I think would help in deep water crashes. I propose that several floating cushion sets... would help find water crashes sooner, but if you add a simple USB memory stick in the center, then have data similar to the current FDR's being fed into it, then finding one of the floaties would give
Provided an aircraft with a fly-by-wire system, there are basically two possible choices when it comes deciding how to let the pilots interface with it: rate control / attitude hold: a deflection... translate to a deflection of the surfaces, mimicking the "old" mechanical control setup. It is my understanding that this is the design choice of Boeing in its new aircrafts. I do not wish to discuss... or Airbus/Boeing certified pilots or even pure civil/(former) military pilots. Does any of you have any reference?
A recent news item mentioned that "black boxes" are typically stored in the tail section of an aircraft to maximize their odds of surviving a catastrophic incident. If they're stored in the rear of the aircraft, presumably flight data and cockpit voice data is transmitted via wires which run the length of the aircraft. Aren't these susceptible to damage during an incident? There have been incidents of explosions and fires which damage flight control cables - aren't the FDR and CVR susceptible in the same way?
I was looking through my virtual radar logs one of the days and found this "glitchy" ADS-B behavior. I am almost 100% sure that this is not due to my antenna or setup since two independent different radars confirmed this weird behavior from FlightRadar24. Also A/C before and after this one did not exhibit this behavior. Does anybody have any thoughts as to what may be happening??? Why is the "skew" at seemingly same angle? Is that anything? In light of MH370, does this happen often, how reliable is that GPS data? Tail # N657UA Boeing 767-300 Typical route between EGLL and KORD Time
that radio beacon. We have not yet picked up anything, but that's typically what those black boxes contain." I was under the (potentially incorrect) impression that flight recorders, by nature...? If so, why? I know that flight recorders are equipped with underwater locator beacons. Are they also equipped with radio beacons (either an active transmitter or a some passive device like a corner... Fleet, which is taking part in the search, said he expected the plane's flight recorders to be floating in the water. He said the recorders, also known as "black boxes", are fitted with radio