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China's Search Vessel Picks up Pulse Signal in South Indian Ocean
- headShrinker 13y ago> The signal, at 37.5 kHz per second, was picked up by a black box locator at 25 degrees south latitude and 101 degrees east longitude. Hz per second? Hertz is a per second unit of measure...
- Nogwater 13y agoMaybe it's an accelerating frequency, like a chirp? :)
- ericbarch 13y agoI think they're referring to the fact that it sends the pulse once per second. Could have been worded differently.
- wglb 13y agoYep, but they did get it right a little further down the article. But what is the monitor an acoustic wave--isn't it a radio signal?
- dannypgh 13y agoNo, it's an acoustic wave. Salt water is a good conductor of electricity, as such only ultra low frequency radio has any chance of penetrating more than a few feet, and the antenna needed to pull that off is prohibitively large for an aircraft. Recommended reading: http://en.m.wikipedia.org/wiki/Communication_with_submarines http://en.m.wikipedia.org/wiki/Communication_with_submarines
- mikeash 13y agoRadio doesn't penetrate water well. It also emits sonar pings for the case where it's in water.
- podperson 13y agoInteresting how effective the Chinese have been (relative to the US and Australia) in the search thus far.
- z92 13y agoChina is heavily involvement in this search as most of the passengers [~150 of 230] were Chinese.
- neurotech1 13y agoThese same tow sensors and underwater autonomous vehicles are used for submarine hunting. Guess which country has a large number of nuclear submarines? US does. Its expected China would try search for our subs.
- peeters 13y agoI'm not sure you can generalize that. It was a Chinese agency that "mistakenly" posted those misleading satellite images, while the U.S. was the first to draw a connection between satellite data and the Indian Ocean as a possible crash area. There have been mistakes, false leads, and promising revelations across the board.
- k-mcgrady 13y ago>> "while the U.S. was the first to draw a connection between satellite data and the Indian Ocean as a possible crash area." Was it not a UK firm that worked that out?
- velniukas 13y agoCorrect, Inmarsat is a UK firm, not US
- peeters 13y agoI'm aware the satellite firm was from the U.K.; I was looking at this timeline: http://www.cnbc.com/id/101485972 http://www.cnbc.com/id/101485972 which implied the White House was the first to reveal it. But other timelines cite the satellite company itself. My point was that "effectiveness" should be measured by results, given there has been a pattern of false leads thus far. We can hope, but don't know for sure, that this new lead won't end up another red herring.
- daturkel 13y agoIncredible last minute discovery considering that they're only relying on it to continue pulsing until tomorrow.
- kapkapkap 13y ago30 days is not by any means a firm deadline for the blackboxes. They are designed to last a minimum of 30 days and usually do last a lot longer.
- mschuster91 13y agoI think it's time for the FAA/JAA to make a regulation that blackbox batteries have to last 3 months or longer. Should not be too much of a cost to retrofit, compared to stuff like live FDR transmission via satellite.
- twic 13y agoI wonder if they could fit them with auxiliary saltwater batteries. So they have N days of power from the main battery, then an additional M days if they land in the sea. Given that it takes a lot longer to find crash sites at sea, that's the main place they need extra energy. That said, i have absolutely no idea if a saltwater battery actually has a higher energy density than some other kind of battery. Probably not.
- jonsen 13y agoIf it separated from the plane and floated, it could be sunlight powered.
- peeters 13y agoIt's hard to design for outlier data. This is the most unusual search in modern aviation history. It is the outlier. With a couple of exceptions, all crash zones are found within days. What makes you think that increasing the battery by a couple of months will deal with the next extraordinary case? What you're suggesting isn't even an order of magnitude more, though 30 days is already a couple of orders of magnitude more than what is needed 98% of the time. Hindsight is 20/20.
- kenrikm 13y agoOr just automatically eject floating GPS beacons on impact. You only need one good ping to the satellite to define the crash area. This is not the first time this has happened. After Air France there should have been some added location method, it took two years to find the black box.
- CamperBob2 13y ago
- yogevyuval 13y agoIs this 37.5 kHz is a standard frequency for black boxes?
- MrMeker 13y agoYes
- daturkel 13y ago"The pulse signal with a frequency of 37.5 kHz is the standard beacon frequency for both so-called black boxes -- the cockpit voice recorder and the flight data recorder, CNN quotes Anish Patel, president of pinger manufacturer Dukane Seacom, as saying. "They're identical.""
- ttflee 13y agoCould it be possible that another black box happened to be found there? EDIT: I'm just asking a question. Why the down vote anyway?
- InclinedPlane 13y agoYou seem to be implying that commercial aircraft go missing over the ocean routinely. That's not the case.
- ttflee 13y agoThe missing of MH370 itself is an outlier(, unprecedented according to the Malaysian officials), too. BTW, I was not implying anything.
- tzs 13y agoIt is extremely unlikely. They only have enough power for about 30 days, and they are generally only on reasonably large, commercial, aircraft, or on military aircraft. If they picked up a black box, and it is not from MH370, then it would mean that another large commercial plane went down there within the last 30 days and either no one noticed it was missing or it was somehow kept secret, or that some military lost a plane there within the last 30 days and kept it secret.
- analog31 13y agoDukane Seacom... is that the same company that made the filmstrip projectors that we dreaded so much in elementary school? Maybe that's where they got the idea for the beep from. Sure enough, same company!
- myth_drannon 13y agoto see it on the map try http://itouchmap.com/latlong.html http://itouchmap.com/latlong.html with lat: -25 long: +101 Sorry I couldn't find a map service that I can share the point
- bdz 13y agohttps://www.google.com/maps/place/25°00'00.0"S+101°00'00.0"E/ https://www.google.com/maps/place/25°00'00.0"S+101°00'00.0"E...
- davidw 13y agoInteresting - there's a bunch of detailed satellite imagery in the general area they've been searching: https://www.google.com/maps?q=25%C2%B000%2700.0%22S+101%C2%B000%2700.0%22E&ie=UTF8&ll=-40.245992,95.844727&spn=30.18728,67.631836&t=h&z=5&iwloc=near https://www.google.com/maps?q=25%C2%B000%2700.0%22S+101%C2%B... I'm guessing that this is because of the crash.
- wglb 13y agoHard to get much further from land.
- supernova87a 13y agoI would suggest to the regulatory/FDR/CVR manufacturers a change to the black box spec, which causes the pinger to only begin pinging 7 days (or some threshold) after the crash. The first few days of pinging are generally useless anyway, because I have not seen any search where a sea vessel was remotely prepared to search in the right area or with the right equipment. Incorporate this delay period (in the absence of anything else), and at least you get an extra week out of the search potential time window.
- dredmorbius 13y agoYour assumption is false. There have been a few notable cases of flight-over-water crashes in which the correct zone wasn't found quickly, but in the case of flight 137, ships were over the presumed crash zone within hours of the aircraft turning up missing. In other cases, particularly where the crash itself was visually observed (US Airways 1549, Ethiopian 961, and others) where a multi-day delay in starting pingers would have been counterproductive. It's also useful to realize that any change you make on flight recorders applies to all equipment, needs to be replace on existing aircraft, and concerns a system which has to work with very high reliability.
- tzs 13y agoIn some cases a delay in starting the pinger would delay finding the recorders, but does that actually cause any noticeable harm? It is important to find the crash site quickly, in order to help any possible survivors, but the pingers do not help with that, do they? Aren't survivors found visually or by the emergency locator transmitter? It could delay the forensics investigation, but that usually takes years to reach a conclusion anyway and depends on inputs other than the recorders, so it is not clear that getting the recorders is even on the critical path for that investigation. On a different note, I wonder if it would make some sense to have echoers instead of pingers? That is, instead of automatically sending out a periodic pulse, they would listen for a pulse and then respond.
- dredmorbius 13y ago
- zmanian 13y agoEver since it became clear that MH370 fell through a gap in the civilian air traffic control system. This has been a story where various nation states cautiously disclose surveillance capability in order to satiate public demand for information.
- lutusp 13y agoQuote: "The signal, at 37.5 kHz per second ..." I haven't seen this construction since the early 1960s, when the new SI units came into use and people were still confused about the meaning of "Hertz". "KHz per second" literally means "thousand cycles per second, per second".