Black box question

[BWSBoy6]

I'm hoping that this isn't a too basic question and it's only out of curiosity; if a plane lands safely, is the black box data kept for future reference, or is it wiped clean? I have tried to search for the answer on this forum and google it but there doesn't seem to be a definitive answer.

My mum asked me this one and it got me thinking

[bucks_raj]

Usually with the OLD GOLD BOLD Pilots & airlines these days Airlines governed by State rules are mandatory-ly required to maintain Flight Op's Quality.Hence the DFDR Capability being much more than CVR almost upto a day or two.The data is physically or over the air using VHF downloaded at first suitable designated location.

Usually Ops/Maintenance bases are equipped for the same.

100% DFDR monitoring is the norm at least here in the subcontinent.

[multis81]

We have a digital flight data recorder (black box). It records for around 25 hours and then starts from the beginning again overwriting older data.
We also have quick access data which the engineers download weekly which records any exceedances etc.
Hope that helps!

[BWSBoy6]

Thank you. That explains perfectly. Much appreciated.

[Straighten Up]

As an aside to this, and most likely asked previously re mh370....why is the data not continually sent to an earth based recording device via radio/satellite?

[mixture]

why is the data not continually sent to an earth based recording device via radio/satellite?

Because someone needs to pay for all that expensive satellite bandwidth, and when that someone has a large fleet of aircraft, the cost soon becomes prohibitive.

Also why waste bandwidth continuously transmitting and storing stuff that you're not really interested in (the whole point of the black box being you're interested in the data running up to an "event").

Basically you'd be looking at a whole redesign of the Blackbox system (as well as perhaps come co-operation from satellite providers on pricing). Given the relatively small number of hull losses, and the even smaller number of hull losses where blackboxes are not recoverable (either due to location, politics or otherwise) ... you can see why a major redesign might not be high on the manfacturers priority list because they know their customers probably won't be falling over themselves to pay more for the newer kit (let alone go back and replace kit on their existing fleet).

One day it'll happen... but you have to understand its not something anybody can wave a wand and make happen overnight.

[Capetonian]

Another aside, I was told recently that 'black' boxes are orange because that is the last colour of the spectrum that fades to grey under water. Most of you probably knew that but I thought it was interesting.

[robertbartsch]

MH 017 - should we have real-time black boxes?

....CNN has video footage of Russian separatist removing one black box from the crash site. ....apparently, the boxes have been transported to Russia and it is believed that 3rd party investigators will not get access to the data.

This is just the another example of why the old technology is no longer adequate.

[glendalegoon]

real time black boxes would not keep the plane safe.

black boxes of any type will not solve the riddle of MH17.

I do predict that the f/o will say to the captain: gee, do you really think we should be flying over ukraine? boom

[infrequentflyer789]

Originally Posted by robertbartsch

....CNN has video footage of Russian separatist removing one black box from the crash site. ....apparently, the boxes have been transported to Russia and it is believed that 3rd party investigators will not get access to the data.

This is just the another example of why the old technology is no longer adequate.

What new technology do you think would help ? AFIRS, for example, is widely touted as the "solution" to AF447 and MH370.

Keeping Track With Afirs | Aviation International News
Flyht: The $100,000 live-streaming black box - Mar. 21, 2014

To quote from one of those:

In an exceptional emergency situation, such as a depressurization, engine failure, fire, unusual attitude change or any other event that may threaten the safety of the aircraft, Afirs automatically begins live streaming of data.

So, after the SAM has fragmented the plane, which is the first any system on board is going to know about the event, you expect the satcom antenna to still be powered and able to track, so that this little box can transmit its data whilst on the way to the ground.

Good luck with that.

[underfire]

I would look at what Boeing is doing with the 787 and some 777 aircraft.

[fireflybob]

They are working on an answer:-

Black Box

Start watching at 49.50

[DozyWannabe]

Originally Posted by msbbarratt

...sending live cockpit voice and flight data...

Flight data yes. Voice data is a very different animal and I can't see any way of burst-transmitting it at a quality that would be of much use forensically.