I was reading the other day that the sonic telltale on the black boxes have a short lifespan.
It seems like a very poor design to just constantly be pinging as that drains batteries and seems unnecessary.
Years ago I designed some multi-use cylinders that could be dropped in the water that could be located later by sending a sequence of tones that they would pick up and respond to. The on-board processor kept them in a sleep state over 99% of the time. They woke every few seconds to listen and immediately shut down if nothing heard. Battery life was a couple of years...not a few weeks as is being said of the black boxes. It would be easy to modify the design to both listen and every few minutes emit a few quick pings, this would only slightly decrease the battery lifespan...I wonder who designed the system in the black boxes? ... seems poorly thought out..
My thoughts also.
Constant acoustic pingers are put on white sharks and they ping for well over a year.
I tried to call a friend of mine this morning who is involved in that tagging to get an idea of how long the pingers last. He would know.
But I know from experience they ping well over a year because he puts the hydrophones out in the spring and gets pings in the summer onward until he pulls the hydrophones out in he winter to avoid them being lost to winter storms. -Tom
I would also have black box(es) that ejected upon the airliner’s contact with water, and they would be buoyant.
Most birds don’t require a one month search. The best option would be an eject-able ELT that floats and sends out a satellite signal. To date the military is the only one who has an eject-able ELT.
I agree with your system too but you would still have too look for it. Best to have both systems on the same box. One that pings away then one that does the sleep/listen/ping thing.
Indeed. What is needed is some sort of underwater transponder.
A better pinger design would be not to transmit at all unless a page from a search vessel is heard. And only wake up to listen for pages for a second every minute. A page would be broadcast from a search vessel on 37.5khz and would include a serial number unique to each ping. A page message should only last a fraction of a second, so waking up for a second every minute should enable to pinger to hear at least one page if there is a search vessel within range.
Search vessels would be broadcasting page messages on 37.5khz continuously, while listening for replies on 8khz. If a pinger happened to hear a page during its wakeful second, it would reply on 8khz with the airplane's serial number and the serial number of the page that it received.
At that point, the search vessel would have two timestamps: when it sent the page, and when it received a reply with the matching serial number. That would establish the distance from the vessel to the wreck. As the vessel moves, additional page replies would be received, allowing the exact position of the wreck to be calculated from the different vessel positions and different ranges.
Then, it would be time to call in the deep-water robot (and a press conference).
I have thought about the missing FLT 370. Why couldn’t the airline companies place a GPS device that would transmit and record the path data of all their air line flights. Transmitting signals and data to satellites is done daily. A recorder could acquire data and if it stopped acquiring data, the last transmission would locate the plane by longitude & latitude data. Once the plane landed at its flight plans destination the data could be dumped to keep from loading the recorder up... Truck line do this now..!! Just a thought..!!