If it floats, it floats away. If it is not found right away, the beacon will eventually die out, then it could be anywhere in the world’s oceans. At least we know that the Air France boxes are down there somewhere in a relatively small area.
Although the planes didn’t disappear without a trace, there were four cases of land-based crashes (two of them were 9/11 planes) in which the black boxes could not be recovered. See my previous post in this thread for a link.
I did read your link. My point was that a crash on land independently preserves evidence in a way that an water based crash does not. As I said in my post, the 9-11 BBRs were unlikely to survive. The El Al Flight 1862 crash in Amsterdam still allowed for recovery of the Flight Data Recorder (whereas the Cockpit Voice Recorder was never found). And the Eastern Airlines Flight 980 BBRs were not exactly lost, it was because an official attempt was never made to retrieve them. It was noted in the Wikipedia link that debris from EA FL980 was starting to appear on the mountain from the melting glacier. My guess is that eventually the one or both of the BBRs will be found.
I should have emphasis that with a crash on terra firma verses the ocean, you have conditions that favor a larger set of forensic evidence for post-crash analysis. Per your link most of the lost BBR occurred over the water, which by nature would result in more speculative conclusions in the accident reports. That’s why one could argue that a real-time up-link for trans-oceanic flights would be more justified then ones over land. But is it worth the cost for such a rare event?
Would the 1947 Star Dust crash qualify (11 aboard)?: 1947 BSAA Avro Lancastrian Star Dust accident - Wikipedia
No, I’m speaking of commercial jets that carry 100 or more passengers. We’ve had small passenger aircraft crash and gone missing in the US for a few months: witness the case of Nevada Airlines in 1969.
A satellite beacon would know where it’s at. That’s the beauty of it. It phones home with a location. It doesn’t have to be found. The aircraft in question was already feeding maintenance information. Heck it could have fed the last known altitude and trajectory to start the process. It’s not much of a change to make it the backup to the black box.
That was a converted Lancaster bomber. It was big for it’s time. They just found it a few years ago in a glacier.
It has to be found before the battery runs out unless you are proposing another source of energy, although if existing units last for 30 days, that would seem like enough time to cover all situations.
I think the point is that a 406 Mhz beacon will transmit it’s GPS location. It only needs to do this once and the searchers know exactly where to look. It’s not perfect, you still need to physically locate it, but you’re search area is very small.
A DC-3 and the Lancastrian are not that much different in size.
Not quite. Not all ELT’s use GPS. Positioning calculations are performed using the Doppler shift of a transmitted signal as received by the satellite. Incidently, scheduled commercial flights are not required to carry an ELT in the US.
You’re missing the point completely. All a beacon needs to do is float long enough to transmit it’s position to a satellite. It’s function is complete. It would be an extension of the ACARS system.
The Lancaster could lift 3 times what a DC3 could. Oddly, they built it as a combo aircraft so the passenger size was smaller than a DC3.
Anything that floats won’t be in the same position an hour later (or if it sinks), so the position transmission would have to be continuous until picked up.
Let me explain this again. A satellite beacon would deploy and transmit a message ACARS style to their operations. The message would transmit the last known position upon impact. It wouldn’t matter if it floats around. It wouldn’t actually have to leave the plane but it would help if the plane sinks too fast to transmit. It just needs to survive the impact and send the message on the company satellite communication channel the plane is already using.
If the device is not found where it transmitted the position because it’s moved to somewhere else, I’d say the beacon’s usefulness is limited.
Or unneeded, if a plane is continuously transmitting position & other data during the entire flight. If it stops transmitting, the last position is where a search should start.
The ACARS system did record a position before it failed. It’s not specifically designed as a beacon system.
My point is that the technology to do this already exists and can utilize the satellite system used for ACARS. Locator beacons are designed to survive and trigger from shock. Instead of sending a tone they could just as easily send a message to a satellite with it’s last known position. It’s not rocket science.
But just the data recorder, not the cockpit voice recorder. And it’s designed to resist that kind of pressure for 30 days, not 2 years, so there is some uncertainty about data readability. Still, it’s a promising development.
The news I read said it would take a week to 10 days to get the device back to land. I guess after 2 years, they’re not in a hurry.
I don’t hold out great hope for recoverable data. But there’s some hope, of course. fingers crossed
Is it ironical, or fitting that this story appeared on May Day?
Actually, the flight data recorder might well be the one with the most useful information. If I had to choose one or the other I’d choose the FDR in this case.
They also enormously over-engineer those memory units, too. There have been cases where information was retrieved even after years of being underwater. No one credible will lay a bet one way or the other until information retrieval is actually attempted.
More like it’s in the middle of the Atlantic and it takes awhile for the boat to get back to shore. I’m sure they’re moving with reasonable haste.