Why not a combined FDR/CVR?

[spagiola]

With the CVR from JT610 still not found, I've been wondering -- given our ability to store vast amounts of data in small volumes, why not combine the CVR and FDR recordings in a single unit? Then, instead of having one CVR and one FDR, we could have two combined CVR/FDRs. If we only find one, we still have all the data. Put one near the nose and one near the tail, and the chances that at least one will be found and/or be usable increase.

Stefano

[noske]

That's how it's already done on the 787.
https://www.flightglobal.com/news/ar...corder-207283/
https://flightsafety.org/asw/jan08/asw_jan08_p47-48.pdf

[kristofera]

And in addition to multiple redundant onboard recording devices, transmit the same data over satcom so at least some of it is available before the recording device(s) are found. This will happen one day, but like everything else it will take time...

[DaveReidUK]

Originally Posted by noske

That's how it's already done on the 787.

And the L3 (Fairchild) FA2100, which is pretty well the industry standard recorder, has a combined FDR/CVR option, although most OEMs specify separate units (for understandable reasons - basket, eggs, etc).

FA2100 CVDR Cockpit Voice and Data Recorder

[EDLB]

On JT610 I am sure if you real get down to it, the reason that the CVR has not been found up to now is the same organisational incompetence, that let the airline test fly with full pax a 737 max. 3x with severe flight control problems.
The 4th time the aircraft won that struggle. As far as I know Lion air has still an AOC. Lion airs mgmt. added several holes to the cheese. So JT610 is not a good case for this argument. Sure it is Boeing’s job to develop airplanes that even the most incompetent airline can safely operate.

After two weeks the CVR Ping could not be heard anymore. They managed to narrow the search radius down to 1km in 30m deep water with the CVR pinging over a week.
Which makes me wonder if the CVR is still in the water...

https://en.tempo.co/read/news/2018/1...itting-Signals

[DaveReidUK]

Originally Posted by EDLB

On JT610 I am sure if you real get down to it, the reason that the CVR has not been found up to now is the same organisational incompetence, that let the airline test fly with full pax a 737 max. 3x with severe flight control problems.

Are you suggesting that it's the airline or the regulator that's carrying out the search for the CVR ? Sounds a tad unlikely.

[Carjockey]

Originally Posted by spagiola

With the CVR from JT610 still not found, I've been wondering -- given our ability to store vast amounts of data in small volumes, why not combine the CVR and FDR recordings in a single unit? Then, instead of having one CVR and one FDR, we could have two combined CVR/FDRs. If we only find one, we still have all the data. Put one near the nose and one near the tail, and the chances that at least one will be found and/or be usable increase.

Stefano

While they are at it, why not allow the CVR to record for the entire flight duration and transmit all data to the operator in the event of a critical situation?
Please don't tell me that this cannot be done, it's just a matter of cost.

[DaveReidUK]

Originally Posted by Carjockey

Please don't tell me that this cannot be done, it's just a matter of cost.

OK - it can be done, it's (just) a matter of cost.

[FE Hoppy]

Originally Posted by noske

That's how it's already done on the 787.
https://www.flightglobal.com/news/ar...corder-207283/
https://flightsafety.org/asw/jan08/asw_jan08_p47-48.pdf

The Ejets also have honeywell DVDRs. One at the front and one at the back.

DIGITAL VOICE DATA RECORDER (DVDR) SYSTEM
The digital voice data recorder system (DVDR) combines a flight data recorder (FDR) and a cockpit voice recorder (CVR) in a single unit. Two DVDR units are installed. DVDR 1 is installed in the forward electronic bay, and the DVDR 2 in the aft electronic bay. Each unit receives, records and preserves all required data parameters and voice recordings from the cockpit crew and area microphones.
The DVDR unit is capable of recording the last 120 min of audio information from cockpit area microphone and primary crew microphones and 25 h of flight data.
The DVDR automatically starts recording audio information as soon as power up is performed and continues until the power down. The flight data begins to be recorded when the first engine is started.
The DVDRs FDR data is available through the MCDU for maintenance purposes only.
If the DVDR power system fails, an EICAS message is generated to indicate the failure. All DVDR EICAS messages are advisory and some of them are inhibited in critical phases of flight, such as takeoff.

[tdracer]

Carjockey, don't underestimate the magnitude of that cost. Sat com is already expensive - and that's just for small, kilobit sized messages. Now you're talking megabits/second - continuous - for each of several thousand aircraft that are in the air at any given time. Most current sat coms use geosynchronous sats - which work fine near the equator, but start getting sketchy above about 50 deg north or south - so polar routes are pretty much out for a system like Inmarsat. So for continous coverage you'd need a fleet of communication sats - similar in concept to the ill fated Iridium system but with many times the bandwidth needed. So basically you'd need a new, semi-dedicated system of satellites to support such a system. Billions of dollars in new investment would be required just to start such a system.