Same with the space shuttle. The use of magnetic tape (only 30 min long for plane IIRC) seems like it suffers from major drawbacks that could be solve by using solid state memory. So why do they still use it?
It was my understanding that there *was *a shift towards using solid state memory, with all newly manufactured products being of this type.
Are you referring to Flight Data Recorders, Cockpit Voice recorders, and the like?
Yep! And the recorders in the Shuttle. On a similar note, we all know about how those on Columbia had a video camera onboard. I’m surprised (especially after Challenger) that they do not have built in cockpit cameras with solid state memory for liftoff and entry.
There’s actually two questions here: Why do they use tape, and why don’t they use solid state. While I’m sure that tape has some advantages that make it worthwhile, solid state devices are light and cheap enough that I see no reason not to have both.
Why would you need video? I think vibrations have a lot to do with it. You vibrate a magnetic tape and you might get static, you vibrate a SSD who knows what could happen. Tape has been proven.
Columbia had a video camera? Inside the cockpit?
I thought that they were wire recorders rather than tape.
I think this is true, but don’t forget that the shuttle was designed using 1960’s technology and changing it may not be worth the trouble and expense.
Also, the shuttles updated technology rather slowly. For example, the initial shuttle computers used magnetic core memory - not solid state. This was not changed until 1990.
Regulations regarding the type and recording time of flight data recorders/cockpit voice recorders on aircraft are set by the aviation authority for the region/country in which the aircraft is registered (although there needs to be agreements in order to fly into other regions).
In Canada, the regulations regarding CVRs and FDRs are found in Part V of the Airworthiness Manual, chapters 525.1457 and 525.1459 respectively. The American regulations set by the FAA are likely nearly identical.
The regulations do not state what medium should be used for these recorders. They specify the data that needs to be recorded, power requirements, location in the aircraft, container type and appearance, etc. If a company has a magnetic tape recorder which meets these criteria, then it can be used onboard aircraft.
Since solid-state memory is a relatively new technology, and while there are recorders of this type and they are becoming increasingly common, if an aircraft already has a magnetic recorder which meets all requirements, there isn’t much incentive to change it out for a solid-state one. It is an extra cost for the airline. If Transport Canada and/or the FAA ever mandates solid-state recorders, then airlines will do it. A lot of things like this get grandfathered in, though - it might not be possible for a variety of design reasons to put a brand new 2 hour solid state recorder into a 40 year old plane, for example.
I seem to recall that CVRs are soon going to be required to have 2 hours of recorded data, rather than the 30 minutes currently allowed. A lot of airlines have already switched to the 2 hour ones, and these are mostly solid-state. FDRs tend to record about 24 hours worth of data, IIRC.
They were - ferromagnetic wire on a spool, very robust as long as the heat they’re subjected to doesn’t exceed the curie point and wipe them. Modern designs use solid-state memory, designed to a much higher temperature spec than commercial memory chips, and housed in a very strong and well-insulated box. Which is orange, for ease of location.
I would say that the old wire spool is the more rugged solution by far, but improvements in materials technology for the enclosure means that solid-state memory is now perfectly viable, and it does have a lot of advantages and seems to work perfectly well. The question is often asked: Why can’t they build the planes out of the same stuff as the black box recorder?
The Shuttles do not have flight data nor cockpit voice recorders per se. They have a great many sensors which are either transmitted in real time via telemetry and/or recorded via local data gathering equipment on board the Shuttle itself.
The point being although after the Columbia accident (much less so after Challenger) some of these devices were able to serve as impromptu FDRs & CVRs they were not designed for this purpose. The recording equipment and media are not contained within hardened cases. The fact that some of Columbia’s survived with useful data intact was by luck, not by design. When the Shuttle was created it was decided that an aircraft-like, hardened FDR would not be worth the weight penalty as all the Shuttle’s critical systems would be constantly monitored (in real time) by ground control. Indeed, the foam hit itself was actually captured on film during liftoff, and the temp sensor and the tire pressure sensor failures were monitored right up until the last moment.
The video was simply from a handheld camcorder that one of the astronauts was using. Not so much as a ‘tourist’ but for some aspects of their completed, ill-fated mission. Again it was merely a fluke that part (or any) of the tape survived.