Malaysian Airlines MH370 contact lost
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Slip and turn
Thanks, Slip and turn.
I have to correct myself. I kept writing 43khz, but I meant 37.5khz, for the frequency of the pinger. Anyway, here's a quote from Slip and turn's first link:
Anyway, the "not originally designed" part is what popped into my head from the very first I heard of the French sending the Nuclear sub to try and hear the pinger. Running the signal through a heterodyne circuit, where they listened only for 37.5khz, would have helped tremendously. That's pretty much what the purpose built listening for pinger equipment does. The sub didn't have equipment purpose built or modified to listen for 37.5khz pingers.
I haven't yet read the dissertation, that the other link connects to, but wouldn't be surprised if it should be a "must read" for anyone thinking of locating a, downed in the water, airliner pinger.
YRP
YRP, The Albert Michelson Interference Theory is actually some of the only stuff I'm good at! I'm apologize if I've changed your whole paradigm on believing that authorities are infallible, and it makes you feel uncomfortable, but, in truth, a little cynicism and experience is a good thing!
If the sub had the equipment mods it needed, AF447 may have been found 2 years earlier. Since it didn't, the area should have been searched by vessels with purpose built equipment, instead of being checked off the "Areas Already Searched" list. YRB, A physics course could help you a lot. I'm sure there are some good, as well as interesting, ones online. I had to learn mine in the olden days, where it was a bit dry. Anyway, good luck, and hope you're melancholy goes away.
Coagie makes a good point. If you are seriously interested in effective research I recommend learning a few quick-win effective research techniques so you don't have to bash fellow PPRuNers for their sources! E.g. start with Google and a few well chosen search words like AF447 acoustic locator sonar frequency.
Then in seconds you might easily stumble over stuff like:
BEA to examine why acoustic sweep missed AF447 recorders - 5/5/2011 - Flight Global
https://fenix.tecnico.ulisboa.pt/dow...issertacao.pdf
Then in seconds you might easily stumble over stuff like:
BEA to examine why acoustic sweep missed AF447 recorders - 5/5/2011 - Flight Global
https://fenix.tecnico.ulisboa.pt/dow...issertacao.pdf
I have to correct myself. I kept writing 43khz, but I meant 37.5khz, for the frequency of the pinger. Anyway, here's a quote from Slip and turn's first link:
While a nuclear submarine was enlisted to assist the search, its sonar interceptor was not originally designed to pick up the 37.5kHz beacon signal. Lower-frequency transmissions, around 8.5-9.5kHz, would have improved the chances, says the BEA. But improved sensor settings enabled the maximum distance for detection to increase from 2,000m to 3,200m during the last 10 days of the acoustic search.
I haven't yet read the dissertation, that the other link connects to, but wouldn't be surprised if it should be a "must read" for anyone thinking of locating a, downed in the water, airliner pinger.
YRP
If you are ignorant of communications engineering (which is ultimately what signal detection is), easy to say they screwed it up the first time...
If the sub had the equipment mods it needed, AF447 may have been found 2 years earlier. Since it didn't, the area should have been searched by vessels with purpose built equipment, instead of being checked off the "Areas Already Searched" list. YRB, A physics course could help you a lot. I'm sure there are some good, as well as interesting, ones online. I had to learn mine in the olden days, where it was a bit dry. Anyway, good luck, and hope you're melancholy goes away.
Last edited by Coagie; 10th Mar 2014 at 06:19. Reason: Capitalized a "T".
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Its a shame during the press conference, the journalists were more interested in the 2 passports, instead of probing into why they are searching the malacca strait, as the explanation given for searching the malacca strait was in my opinion vague at best. It just feels like they know something more than they are letting on at the moment.
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KUALA LUMPUR, Malaysia: Vietnamese searchers on ships worked throughout the night but could not find a rectangle object spotted Sunday afternoon that was thought to be one of the doors of a Malaysia Airlines passenger jet that went missing more than two days ago.
Terrorism is now being considered, so they must have something.
Chief of Malaysian CAA, press conference he did not take questions which were unrelated to SAR.
At the moment they do not have anything that they can confirm as wreckage.
Vietnamese report regarding a floating door is not verified by Vietnamese authorities today. (reading between the lines, it may have been a valid report but either it or what it related to can't be verified at the moment)
A search radius of 50 NM from last point of contact has been conducted/completed
The search North of Malacca straights was done because of the chance the aircraft may have begun to turn and for no other reason.
40 ships searching 24hours per day and 34 aircraft 7am to 7pm.
Vietnam, Australia, Singapore, China, Malaysia, Philippines Thailand USA involved in search.
FAA arrived this morning.
All bags on the flight were X-rayed according to international standards.
Offered to fly 5 next of kin from each passenger to KL.
They are looking at all angles for the cause.
No signals detected from the aircraft after the initial lost contact.
Oil slick amples sent to lab.
Report of tail wreckage was found to be logs tied together to form a pontoon.
They are puzzled and perplexed.
He deferred numerous questions regarding security and the two fake passport holders, quoting it could interfere with investigations and it was a matter for the investigators, not him. Bear in mind English is not his first language but he appeared calm in control, fluid and open.
Last edited by mickjoebill; 10th Mar 2014 at 04:59.
compare the photo of the door that was touted as possibly from the aircraft with photos of the B777, looks nothing like it. The photo showed a large central (window) in the door, all the Malysian B777 doors have a small window at the side and the colour stripe paint along the bottom.
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Just for reference MS990, which descended rapidly nose down in to the sea at night, left very little on the surface:
"At sunrise, the U.S. Merchant Marine Academy training vessel Kings Pointer found an oil sheen and some small pieces of debris."
"At sunrise, the U.S. Merchant Marine Academy training vessel Kings Pointer found an oil sheen and some small pieces of debris."
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MAS370 LASt Known Position
I put the last known latitude and longitude according to Flightaware 4.7073N 102.5278E into Google Earth and it came up with a Malaysian mountaintop in the flight path of the plane not middle of ocean.
I assume this is because Flightaware coverage is incomplete?
See
Flight Track Log ? MAS370 ? 08-Mar-2014 ? WMKK / KUL - ZBAA / PEK ? FlightAware
I assume this is because Flightaware coverage is incomplete?
See
Flight Track Log ? MAS370 ? 08-Mar-2014 ? WMKK / KUL - ZBAA / PEK ? FlightAware
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There now seems to be speculation that MH 370 may have "disintegrated" at FL350. I cannot imagine what would cause it to virtually evaporate so that no debris could be found. Surely even a very large explosion would blow some parts off the aircraft that would remain intact?
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Welll, it could be false, it could be true...i dont know either...but weird
Do your seismic sensors stay on the bottom
No, our hydrophone sensors are in a towed-cable array, up to 8000 m long by 800 m wide, moving at 4.5 kts. That's the reason we need fishing boats to keep out of the way, for our mutual benefit. We don't want to tangle with their drift nets and they don't want to lose their gear.
The hydrophones have a bandwidth of less than 10 Hz to 200-300 Hz. They would certainly register the low-frequency noise from an ocean impact in the vicinity - we pick up ship's propellor noise from quite long distances.
However, as a practical matter, there are no seismic vessels operating at the moment, since we are still in the NE Monsoon. Although this is the dry season in southern Vietnam, the winds and waves are too high for us to operate - too much wave-induced noise in the sensors.
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1 Group claims responsibility ....
A group that calls itself the Chinese Martyrs' Brigade has claimed responsibility for crashing Malaysia Airlines flight MH370, which has remained missing after losing contact with ground control at 1:20am on Saturday.
Chinese group claims responsibility for flight MH370?Politics?News?WantChinaTimes.com
Chinese group claims responsibility for flight MH370?Politics?News?WantChinaTimes.com
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Detachable ELTs
The impact-detachable, floatable external ELT has been available for turboprop aircraft and helicopters for years (i.e. look at the RCAF fleet). Had something like that been adopted for airliners, it would be worth its weight in gold right now...
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Thank you, I42..
By the way, my family has been in the O&G business for 4 generations, but it was only in last month's JPT that I learned of exploration in Vietnamese waters. Obviously I haven't been paying enough attention.
By the way, my family has been in the O&G business for 4 generations, but it was only in last month's JPT that I learned of exploration in Vietnamese waters. Obviously I haven't been paying enough attention.
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I posted many pages ago that the lack of wreckage or even reports of an explosion in such an area, populated as it is by some of the most intensive marine traffic in the world, is the most perplexing part of this.
Every hour without a sign of wreckage deepens the mystery further.
I do not believe that terrorism is necessarily involved simply because fake passports were being used. There is a myriad of reasons why that could be so and conversations with officials in the know about such things confirms it is not necessarily unusual.
A break-up at 35,000 feet would have left a large identifiable debris field. Something would have been found by now.
That is has not suggests either they are looking in the wrong place, or the debris is in a very localised area, possibly due to the aircraft going vertically into the water.
I find it difficult to ascertain why the searchers would be looking in the wrong place, considering the plethora of primary and secondary radars that would have tracked the aircraft.
An aircraft going vertically into water at high speed would have a limited number of causes.
Pilot disorientation following some malfunction - similar to Adam Air Flight 547.
Terrorist Action - similar to 9/11
Pilot suicide - similar to Silkair 185 or Egypt Air 990
In the light of the increasingly weird lack of debris/mayday calls/ACARS info/visual sightings by witnesses of explosions or fire on a dark moonless night, the options are becoming limited.
Every hour without a sign of wreckage deepens the mystery further.
I do not believe that terrorism is necessarily involved simply because fake passports were being used. There is a myriad of reasons why that could be so and conversations with officials in the know about such things confirms it is not necessarily unusual.
A break-up at 35,000 feet would have left a large identifiable debris field. Something would have been found by now.
That is has not suggests either they are looking in the wrong place, or the debris is in a very localised area, possibly due to the aircraft going vertically into the water.
I find it difficult to ascertain why the searchers would be looking in the wrong place, considering the plethora of primary and secondary radars that would have tracked the aircraft.
An aircraft going vertically into water at high speed would have a limited number of causes.
Pilot disorientation following some malfunction - similar to Adam Air Flight 547.
Terrorist Action - similar to 9/11
Pilot suicide - similar to Silkair 185 or Egypt Air 990
In the light of the increasingly weird lack of debris/mayday calls/ACARS info/visual sightings by witnesses of explosions or fire on a dark moonless night, the options are becoming limited.
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And therein lies the difference.
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Sorry if this has been answered before (looked through several pages, don't see the answer):
What is the exact extent of ATC primary radar coverage of the Gulf of Thailand?
If the transponder of MH370 was turned off or otherwise disabled at the last known position, 40 min after takeoff, but the aircraft itself remained in one piece at that point, would the aircraft still be visible on any radar afterwards?
Based on available information, is it possible that MH370 had a massive electrical failure and/or was hijacked 40 min after takeoff and eventually was ditched into the ocean, say, in South China Sea halfway between Vietnam and Philippines (1000 miles from the last known position), thus explaining why no one saw an explosion and no one seems to be able to find any debris?
P.S. And while we're at it, how far would a 777 glide if (worst case scenario) a power failure shut down all electronics and all engines at the altitude of 35000 ft and airspeed of 470 knots?
What is the exact extent of ATC primary radar coverage of the Gulf of Thailand?
If the transponder of MH370 was turned off or otherwise disabled at the last known position, 40 min after takeoff, but the aircraft itself remained in one piece at that point, would the aircraft still be visible on any radar afterwards?
Based on available information, is it possible that MH370 had a massive electrical failure and/or was hijacked 40 min after takeoff and eventually was ditched into the ocean, say, in South China Sea halfway between Vietnam and Philippines (1000 miles from the last known position), thus explaining why no one saw an explosion and no one seems to be able to find any debris?
P.S. And while we're at it, how far would a 777 glide if (worst case scenario) a power failure shut down all electronics and all engines at the altitude of 35000 ft and airspeed of 470 knots?
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Anyone else get the feeling that we're never going to know the true cause?
Last edited by thcrozier; 10th Mar 2014 at 05:40.
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3db
3db, I messed up as well. I kept writing 43khz, when I should have written 37.5khz. I work off the top of my head too much without double checking. Anyway, thanks.
Coagie,
I just looked up 40kHz in the Radio Regs, it is allocated to fixed maritime mobile - they would not be putting a distress beacon in that band without guard channels. Also, a google search reveals a circuit diagram which has a loudspeaker symbol as the "final bit" and not an aerial symbol, so my apologies, you are correct. Must google before posting for things I am not familiar with!
I just looked up 40kHz in the Radio Regs, it is allocated to fixed maritime mobile - they would not be putting a distress beacon in that band without guard channels. Also, a google search reveals a circuit diagram which has a loudspeaker symbol as the "final bit" and not an aerial symbol, so my apologies, you are correct. Must google before posting for things I am not familiar with!