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Pihero
Posts: 4318
Joined: Mon Jan 31, 2005 5:11 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting WarrenPlatts (Reply 249):Nice try buddy! You "round up" coordinates to the nearest degree, and then wonder why the speeds are all different!!!

So give us your exact coordinates so we could benefit from your wisdfom.
(That's obviously a challenge )
(or a dare)

 Quoting WarrenPlatts (Reply 249):d I am also happy to know that you think my "moronic" diagrams are pretty! lol!

That's just the pacvkage. What's inside could be rather smelly. LOL
Contrail designer

Pihero
Posts: 4318
Joined: Mon Jan 31, 2005 5:11 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting WarrenPlatts (Reply 249):And yes, "azimuth" is the correct term to refer to the horizontal component of the direction to a satellite.

Yes, just a "direction" to something that's hanging 35000 km above.
When the position of origin ( here the footprint ) is known, it becomes a compass bearing.
Can't have it both ways.
Contrail designer

LTC8K6
Posts: 1534
Joined: Fri Jun 05, 2009 8:36 pm

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

I wanted to bring the subject up again to get other opinions, and because I think there may be an important clue in there somewhere. Perhaps a clue as to why there seemed to be a jump to "criminal act" by officials.

WarrenPlatts
Posts: 517
Joined: Wed Mar 26, 2014 6:03 pm

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting Pihero (Reply 251):Quoting WarrenPlatts (Reply 249): And yes, "azimuth" is the correct term to refer to the horizontal component of the direction to a satellite. Yes, just a "direction" to something that's hanging 35000 km above. When the position of origin ( here the footprint ) is known, it becomes a compass bearing. Can't have it both ways.

Recall from your celestial navigation days. The proper nomenclature when referring to satellites is the same as for stars: remember when you would pick out a few stars or planets to get your fix, look them up in the ephemeris and get two numbers: the expected altitude, and the expected azimuth?

A "bearing" refers more to surface items like other ships, unknown radar contacts, or navigational landmarks IRRC.

Also:

 Quote:The point at which a line between the satellite and the centre of the Earth intersects the Earth’s surface is called the subsatellite point.

Not footprint....

Glad to continue to be of service to you sir!

TheRedBaron
Posts: 3276
Joined: Tue Mar 29, 2005 6:17 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

Can you put exactly were you think the aircraft went down? a window of lets say 50 by 50 km square?

I ask you because maybe in the future you will be right and Ill have to cook my hat and eat it, but I just want to be sure that went they find the 777 we will know for sure if you were right in the first place.

Thank you

TRB
The best seat in a Plane is the Jumpseat.

JHwk
Posts: 575
Joined: Wed Jan 30, 2013 2:11 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

Fun to load the information in, but the truth of the matter is that the plane can be anywhere between a hypothetical 550kt path and the 300kt path, and at least 100nm on either side of the arc. Independent data is needed to corroborate all of their assumptions; so far the best independent data is the sonar locations, although they are biased by the Inmarsat information.

Pihero
Posts: 4318
Joined: Mon Jan 31, 2005 5:11 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting Pihero (Reply 251): When the position of origin ( here the footprint ) is known, it becomes a compass bearing. Can't have it both ways.
 Quoting WarrenPlatts (Reply 253):A "bearing" refers more to surface items like other ships, unknown radar contacts, or navigational landmarks IRRC.

Yes, as you write to the surface. And your initial appellation was wrong.
I went straight to wiki, and lo and behold, there's the diagram above.
Question : Does it fit your drawing ?
And what are the values of these bearings ? And where do they come from ?
Pray tell.

 Quoting TheRedBaron (Reply 254):Warren I really won't go into details of your maps.

You should at least reproduce my computations, on the map he provided or better, with the coordinates he 'll provide, if ever.
I'm not holding my breath.
He' ll try as usual to wriggle his way around it.
Contrail designer

747megatop
Posts: 1750
Joined: Wed May 23, 2007 8:22 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting JHwk (Reply 255): but the truth of the matter is that the plane can be anywhere between a hypothetical 550kt path and the 300kt path, and at least 100nm on either side of the arc.

In other words none the wiser. In simple terms nobody knows where the plane is or most likely is.

nupogodi
Posts: 933
Joined: Mon Mar 10, 2014 10:58 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting 747megatop (Reply 257):In other words none the wiser. In simple terms nobody knows where the plane is or most likely is.

Well, it's more likely to be in the place they heard ULBs in the middle of the Indian Ocean, but I hear what you're saying and agree

Plotting all of these paths is such a waste of time unless you are on the investigative team and have all the data ... everyone's assuming a constant ground speed throughout ... why? That's far from realistic. But keep on bickering and drawing lines on globes. I'm sure it's at least fun.
A man must know how to look before he can hope to see.

747megatop
Posts: 1750
Joined: Wed May 23, 2007 8:22 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting nupogodi (Reply 258):Well, it's more likely to be in the place they heard ULBs in the middle of the Indian Ocean, but I hear what you're saying and agree

Do you or anybody knows how long it will take let's say 2 or 3 remus 6000 auvs to cover (scan the Ocean floor) along that entire arc (plus 100 nautical miles on either side) right from let's say the SouthWest of Indonesia/NorthWest of Australia ..all the way to the SouthWestern most portion of that Arc off Perth? Looks like a brute force approach is the only option if nothing else turns up in the location where they heard pings from the ULB.

Looks like they are planning to bring in other assets - https://au.news.yahoo.com/thewest/latest/a/22861340/new-devices-in-mh370-search/

[Edited 2014-04-22 16:15:19]

[Edited 2014-04-22 16:16:09]

nupogodi
Posts: 933
Joined: Mon Mar 10, 2014 10:58 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting 747megatop (Reply 259):Do you or anybody knows how long it will take let's say 2 or 3 remus 6000 auvs to cover (scan the Ocean floor) that entire arc (plus 100 nautical miles on either side) right from let's say the SouthWest of Indonesia/NorthWest of Australia ..all the way to the SouthWestern most portion of that Arc off Perth? Looks like a brute force approach is the only option now.

I don't know, but it can be calculated. The REMUS 6000 has a maximum speed of 5kt, if we know how far out its SSS can see (and I don't know that) we can calculate many km^2 it can image per hour. Then we just divide the search area size by that value to get the number of hours it would take to image all of it. Divide it further by how many of them you have. Of course this does not take into account the descent time, maneuvering time, ascent time, download/analysis, reprogramming etc and it assumes a straight-line search at maximum speed.

I just don't know enough about side-scanning sonar and the search pattern it would use to be able to calculate that value, but it is calculable. I, uh, would imagine it's very very very large. And they'd find a lot of non-plane nonsense... I really don't see it as a very practical approach, but who knows, this is unprecedented in our time.
A man must know how to look before he can hope to see.

WingedMigrator
Posts: 1771
Joined: Wed Oct 26, 2005 9:45 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting nupogodi (Reply 258):everyone's assuming a constant ground speed throughout ... why?

Exactly. The constant ground speed assumption is explicitly stated in the Inmarsat picture with the red and yellow tracks, and it is a horrible assumption that everybody just ran with and never looked back. It may indeed be used to retrieve the ping rings that were not published (with significant error margins that are rarely discussed when we use six decimal places) but that's about it.

Ground speed depends on a bunch of things.
1) winds aloft-- obviously
2) temperature, somewhat less obviously. Most aviation buffs think that the speed of sound varies with density (ask around you, you'll be amazed!) but it actually only varies with temperature. When you fly at a desired Mach number, the temperature will determine your speed.
3) cost index

art
Posts: 3044
Joined: Tue Feb 08, 2005 11:46 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting nupogodi (Reply 258):Quoting 747megatop (Reply 257):In other words none the wiser. In simple terms nobody knows where the plane is or most likely is. Well, it's more likely to be in the place they heard ULBs in the middle of the Indian Ocean, but I hear what you're saying and agree Plotting all of these paths is such a waste of time unless you are on the investigative team and have all the data ... everyone's assuming a constant ground speed throughout ... why? That's far from realistic. But keep on bickering and drawing lines on globes. I'm sure it's at least fun.

I think on the same lines as you... I think.

The only contained area in which seabed evidence of MH370 is likely to be found is within a short range of the reported reception of pings IMO.

If one accepts that Inmarsat deduced correctly that the aircraft flew south, the absence of any data after the last handshake (headings, airspeeds, wind velocities, residual flight time et al) make it impossible to predict where the flight ended without allowing for a very large margin of error IMO.

Pihero
Posts: 4318
Joined: Mon Jan 31, 2005 5:11 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting nupogodi (Reply 258):.. everyone's assuming a constant ground speed throughout ... why? That's far from realistic.

No. A constant True Airspeed
The ground speed will derive from Heading / Wind / Magnetic variation...
It can further be refined with OAT data.
As for the speeds, we could proceed through elimination : We know the aircraft has been airborne to 00:19 Z, that should give us, with a set of altitude assumption a pretty accurate set of possible CAS that would check that endurance and that last line of position : too high and the flight would have been shorter and would not check the last LOP ; too slow and we wouldn't be able to verify both requirements.

Here is the usual dilemma all investigations are facing : No proof of evidence is not no evidence of proof.

 Quoting nupogodi (Reply 258): But keep on bickering and drawing lines on globes. I'm sure it's at least fun.

Anyone interested in trying to find an explanation as to the events should at the very least check the validity of all the claims on this thread... Otherwise, there are activities that are more satisfying : cooking for instance.
Until you do that and verify the claims on technical solutions, you're wasting your time... because we're into flight safety, after all.

At the very least, a modicuim of trust on a group of scientists working a solution - the *loci*- of which you do not have the details of is required : After all, everybody involved in the search and who have the info on the method and the data, is trusting these scientists.

And yes, six weeks after the event, it is bloody frustrating that the authorities - whoever they be - haven't come out with a preliminary report showing the slightes bit of information :
The total fuel on board
The initial flight plan
The aircraft equipment ( safety, O2, Comms...)
The Inmarsat data...

That absence of prelims is contrary to ICAO recommendations.

Without these, we are only into conjectures.
That's why responsible posters have refrained to propose any possible scenario... leavng the field totally free for all sorts of theories... very few of which hold any water when faced with technical arguments.
Contrail designer

Pihero
Posts: 4318
Joined: Mon Jan 31, 2005 5:11 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting art (Reply 262):The only contained area in which seabed evidence of MH370 is likely to be found is within a short range of the reported reception of pings IMO.

...and how was that area determined ?
Contrail designer

777Jet
Posts: 6977
Joined: Sat Mar 08, 2014 7:29 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

Nothing would surprise me because, like you said, nothing - not one single thing - has been found yet. I would not be surprised if nothing is ever found, if debris wash up one day on a beach somewhere, if the plane / wreckage is found somewhere completely different or even if the plane is used in a future suicide mission... However, given that this has gone on for over six weeks, I don't feel that a cover-up is taking place. If so, I would want those in the know to pay back all the SAR costs associated with searching for the plane in an area where others know that it is not - that is - if such a cover up ever comes to light... I suspect that if the Bluefin-21 finds nothing then they will need to use a more capable craft with a good track record like the REMUS 6000.
DC10-10/30,MD82/88/90, 717,727,732/3/4/5/7/8/9ER,742/4,752/3,763/ER,772/E/L/3/W,788/9, 306,320,321,332/3,346,359,388

dtw2hyd
Posts: 7524
Joined: Wed Jan 09, 2013 12:11 pm

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

There was another suggestion these pings could be from a tagged fish. It appears tropical tuna is tagged and tracked until June in Indian Ocean. They use 34 Khz and 50 Khz transmitters.

One fine day either fishermen/surfers/beach-goers from Australia/Indonesia/Madagascar will find the first piece of debris.

nupogodi
Posts: 933
Joined: Mon Mar 10, 2014 10:58 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting Pihero (Reply 263):No. A constant True Airspeed

I don't think you're correct here. The ping arcs/loci/whatever you want to call them are on the ground, not moving with the air. If you assume a constant TAS, you need to make a huge number of other assumptions to be able to calculate GS to be able to draw lines between those arcs that make sense. Otherwise you are using completely incompatible numbers.

I sure hope to god everyone is talking GS. It's the only thing that makes sense when you're talking about the satellite data.

[Edited 2014-04-22 17:02:49]
A man must know how to look before he can hope to see.

777Jet
Posts: 6977
Joined: Sat Mar 08, 2014 7:29 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting Pihero (Reply 263):That absence of prelims is contrary to ICAO recommendations. Without these, we are only into conjectures. That's why responsible posters have refrained to propose any possible scenario... leavng the field totally free for all sorts of theories... very few of which hold any water when faced with technical arguments.

I believe that it is also because they are afraid to possibly be wrong. Or, be wrong again. Or, because like the rest of us, they really have no clue what happened... It could be anything from something on the plane failed to a pilot spilled his coffee to a hi-jacking to a suicidal pilot - the possibilities are endless. Let's hope the plane / wreckage is eventually found and that the true cause of this incident is discovered.

 Quoting nupogodi (Reply 267):Quoting Pihero (Reply 263): No. A constant True Airspeed I don't think you're correct here. The ping arcs/loci/whatever you want to call them are on the ground, not moving with the air. If you assume a constant TAS, you need to make a huge number of other assumptions to be able to calculate GS to be able to draw lines between those arcs that make sense. Otherwise you are using completely incompatible numbers. I sure hope to god everyone is talking GS. It's the only thing that makes sense when you're talking about the satellite data.

I hope so too.

Wouldn't airspeed need to be converted into ground speed anyway in order to provide the location of where to search on the ground?
DC10-10/30,MD82/88/90, 717,727,732/3/4/5/7/8/9ER,742/4,752/3,763/ER,772/E/L/3/W,788/9, 306,320,321,332/3,346,359,388

prebennorholm
Posts: 7020
Joined: Tue Mar 21, 2000 6:25 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting 747megatop (Reply 259):anybody knows how long it will take let's say 2 or 3 remus 6000 auvs to cover (scan the Ocean floor) along that entire arc (plus 100 nautical miles on either side) right from let's say the SouthWest of Indonesia/NorthWest of Australia ..all the way to the SouthWestern most portion of that Arc off Perth?

I read somewhere days ago that Remus 6000 can scan 130 km2 per day. I forgot where I read it, and I cannot prove validity, but nevertheless it sounds reasonable to me.

With the search area in the hundreds of thousands of km2 we are talking years rather than days.
Always keep your number of landings equal to your number of take-offs

777Jet
Posts: 6977
Joined: Sat Mar 08, 2014 7:29 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting prebennorholm (Reply 269):With the search area in the hundreds of thousands of km2 we are talking years rather than days.

Does anybody think that the SAR would be continued for years in the absence of any debris or that it will eventually be called off at some point in time?
DC10-10/30,MD82/88/90, 717,727,732/3/4/5/7/8/9ER,742/4,752/3,763/ER,772/E/L/3/W,788/9, 306,320,321,332/3,346,359,388

nupogodi
Posts: 933
Joined: Mon Mar 10, 2014 10:58 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting 777Jet (Reply 270):Does anybody think that the SAR would be continued for years in the absence of any debris or that it will eventually be called off at some point in time?

Sadly the only thing that really matters in the long run.

[Edited 2014-04-22 17:28:34]
A man must know how to look before he can hope to see.

BaconButty
Posts: 816
Joined: Tue Aug 06, 2013 3:42 pm

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting prebennorholm (Reply 269):I read somewhere days ago that Remus 6000 can scan 130 km2 per day. I forgot where I read it, and I cannot prove validity, but nevertheless it sounds reasonable to me.

The REMUS 6000 doesn't scan anything. It's a platform (mission planning, guidance etc). All sorts of payloads can be integrated - side scan sonar, multi beam echo sounders, magnetometers/gradientometers, sub bottom profilers, cameras and more. The Bluefin 21 and Remus 6000 aren't that different as far as platform goes, though the 4500m depth limit of this particular uav is clearly marginal for this specific mission. Obviously, if you could choose your sensor payload in advance it might be different from the uav being used, which is only there due to speed of deployment.

But as for 130km2? Depends on the sensor. At a whopping 150 linear km and a 500m swath width you'll get 75km2 - then subtract the dead area along the track for sss - but it would probably be useless for the purposes of this search. These guys are doing 25-30km2 / mission (which, with Ryanair like utilisation rates and F1 turnarounds you might do in a day) with the bluefin, and it wouldn't be much different with the Remus.

[Edited 2014-04-22 17:36:24]
Down with that sort of thing!

nupogodi
Posts: 933
Joined: Mon Mar 10, 2014 10:58 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting BaconButty (Reply 272):These guys are doing 25-30km2 / mission (which, with Ryanair like utilisation rates and F1 turnarounds you might do in a day)

Then you're looking at about 9 years to image 100,000 km^2 with SSS with one AUV.

That's about 67 million dollars assuming a fairly conservative \$20k/day cost (which is a number I pulled out of my behind).

Such an operation might have scientific merit though...

[Edited 2014-04-22 17:45:08]
A man must know how to look before he can hope to see.

747megatop
Posts: 1750
Joined: Wed May 23, 2007 8:22 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting nupogodi (Reply 260):I don't know, but it can be calculated. The REMUS 6000 has a maximum speed of 5kt, if we know how far out its SSS can see (and I don't know that) we can calculate many km^2 it can image per hour. Then we just divide the search area size by that value to get the number of hours it would take to image all of it. Divide it further by how many of them you have. Of course this does not take into account the descent time, maneuvering time, ascent time, download/analysis, reprogramming etc and it assumes a straight-line search at maximum speed. I just don't know enough about side-scanning sonar and the search pattern it would use to be able to calculate that value, but it is calculable. I, uh, would imagine it's very very very large. And they'd find a lot of non-plane nonsense... I really don't see it as a very practical approach, but who knows, this is unprecedented in our time.

Tried looking around for the SSS swath range of the Remus 6000, this is the best i could find

"Remus 6000 autonomous underwater vehicles, or AUVs. These torpedo-shaped robots can travel up to 22 hours at a stretch, systematically scanning the seabed with sonar that images a kilometre-wide swath with every pass. " - See more at http://www.popularmechanics.co.za/sc...-of-disaster/#sthash.8ObF6fPe.dpuf

More links to Remus 6000 specs -

http://www.km.kongsberg.com/ks/web/n...e/REMUS-6000-Specs.pdf?OpenElement

http://www.whoi.edu/page.do?pid=38144

http://www.geo-matching.com/products/id1964-remus-6000.html

dtw2hyd
Posts: 7524
Joined: Wed Jan 09, 2013 12:11 pm

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting nupogodi (Reply 273):That's about 67 million dollars assuming a fairly conservative \$20k/day cost

Its more like \$200,000/day for AUV rent, Support vessel rent and technician charges.

BaconButty
Posts: 816
Joined: Tue Aug 06, 2013 3:42 pm

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

Quick! Blame it on pilot suicide

[Edited 2014-04-22 17:50:34]
Down with that sort of thing!

nupogodi
Posts: 933
Joined: Mon Mar 10, 2014 10:58 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting 747megatop (Reply 274):Tried looking around for the SSS swath range of the Remus 6000, this is the best i could find "Remus 6000 autonomous underwater vehicles, or AUVs. These torpedo-shaped robots can travel up to 22 hours at a stretch, systematically scanning the seabed with sonar that images a kilometre-wide swath with every pass. "

Well then at full speed that would be 5nm/hr = 9.26km/hr * 1km = 9.26km^2/hr. It can last 22 hours, but it's not on station that whole time, if we give it a generous 15 hours/mission that's 138.9km^2/mission at full speed. That's somewhat in line with what prebennorholm, but what BaconButty said is valid too.

And we certainly can't assume full speed or perfect mission turnaround time or what have you.

Any way you slice it, it would be an insanely lengthy operation.
A man must know how to look before he can hope to see.

nupogodi
Posts: 933
Joined: Mon Mar 10, 2014 10:58 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting DTW2HYD (Reply 275):Its more like \$200,000/day for AUV rent, Support vessel rent and technician charges.

Well then!

I saw the mini documentary of them rebuilding that plane in Antarctica, and it only cost like \$5k/day to have a whole crew there. I pulled a number out of my butt and figured, well, 4 times as expensive sounds reasonable. But really? \$200k/day? Jesus.

So a 670 million dollar operation. Over 9 years. Good luck getting Malaysia to pay for that.

[Edited 2014-04-22 17:55:43]
A man must know how to look before he can hope to see.

777Jet
Posts: 6977
Joined: Sat Mar 08, 2014 7:29 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting nupogodi (Reply 278):Quoting DTW2HYD (Reply 275): Its more like \$200,000/day for AUV rent, Support vessel rent and technician charges. Well then! I saw the mini documentary of them rebuilding that plane in Antarctica, and it only cost like \$5k/day to have a whole 40+ man crew there. I pulled a number out of my butt and figured, well, 4 times as expensive sounds reasonable. But really? \$200k/day? Jesus. So a 670 million dollar operation. Over 9 years. Good luck getting Malaysia to pay for that.

The thing about this is... what Malaysia decide to do or not do will have consequences for them.

On the other hand, it wouldn't take China long to print that kind of money
DC10-10/30,MD82/88/90, 717,727,732/3/4/5/7/8/9ER,742/4,752/3,763/ER,772/E/L/3/W,788/9, 306,320,321,332/3,346,359,388

747megatop
Posts: 1750
Joined: Wed May 23, 2007 8:22 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting nupogodi (Reply 278):So a 670 million dollar operation. Over 9 years. Good luck getting Malaysia to pay for that.

Cheaper to start streaming CVR/FDR data for aircraft in future i guess  . There is another thread about "lessons learned" where multiple solutions are being hotly debated right from tracking planes at all times to being able to stream CVR/FDR data either in realtime or triggered transmission on impact. Either ways, strong lessons learned and recommendations are going to come out of this incident not to mention the fact that militaries have been caught red faced and napping in that region.

nupogodi
Posts: 933
Joined: Mon Mar 10, 2014 10:58 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting 777Jet (Reply 279):On the other hand, it wouldn't take China long to print that kind of money

Regardless of the length or cost of the operation, it would have very little guarantee of success. And remember, these estimates (9 years at 30km^2/day) are based on 100,000km^2 search area ... what search area are we proposing here? It could be many many times bigger than that. And over such a long period of time, debris might get buried ... you'd need to look at anything remotely interesting with sub-surface sonar ...

No way. The "brute force" approach to search underwater is completely infeasible in my opinion at this point, even with all the money in the world. If they don't find it where they heard those ULB pings, they'll need to find another way to locate a search area. If they can't, well... You know the rest.
A man must know how to look before he can hope to see.

BaconButty
Posts: 816
Joined: Tue Aug 06, 2013 3:42 pm

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting nupogodi (Reply 277):Well then at full speed that would be 5nm/hr = 9.26km/hr * 1km = 9.26km^2/hr. It can last 22 hours, but it's not on station that whole time, if we give it a generous 15 hours/mission that's 138.9km^2/mission at full speed. That's somewhat in line with what prebennorholm, but what BaconButty said is valid too.

Don't mean to be argumentative (I like your posts) but the assumed 1km swath width is way too high. Which is why prebennorholm 's figures are way off. If you look at the specs of various auv integrated side scan sonars and they're an order of magnitude less in the likely frequencies we're talking about. Although very much a littoral auv (where 99% of the utility is) the iver auv web site has lots of good sss images at various frequencies:
http://www.iver-auv.com/sidescan_sonar.html
http://www.iver-auv.com/sidescan_sonar3.html
http://www.iver-auv.com/sidescan_sonar2.html
which illustrate the difference between resolution and swath width.

But I agree with your general point, that it's unfeasible to search the kind of vast areas discussed.

[Edited 2014-04-22 18:12:42]
Down with that sort of thing!

747megatop
Posts: 1750
Joined: Wed May 23, 2007 8:22 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting nupogodi (Reply 281):hey'll need to find another way to locate a search area.

Which makes the statement - Finding the hay stack before finding the needle in the hay stack very true.

bluesky9
Posts: 105
Joined: Sun Mar 23, 2014 1:26 pm

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting 9MMPQ (Reply 204):I have no idea where you get this ''fact'' from but it completely ignores the entire cargo process as it exists which already starts from the shipper onwards. Not just anyone gets to send out cargo & unknown or unsecure cargo does not make it out of the warehouse without getting checked out & signed off on.

Yes it turns out it is probably going to far to call this a "fact". It is widely reported on the internet, though I wouldn't call the sources authoritative . Some specifically mention that the X-Ray scanning was out. It was mentioned by some posters here gr325 Reply 238 Part 24 - quoting tweets from @TheLeadCNN & @flyingwithfish (these tweets exist, though I cannot see whether this was actually retweet from CNN) , also Dalavia Reply 344 in Part 24, nm2582 Reply 118 Part 25 - reported rumours cargo wasn't scanned, PlanesNTrains Reply 188 Part 26 says "cargo not screened on this flight", slinky09 Reply 28 Part 26, "Some reporters have talked about cargo not being screened", and others.

But as you say it looks like scanning is more nuanced than most people (including me) would have thought. So it is quite likely that cargo coming from the authorized freight forwarders is routinely not scanned at many international airports. There is a good article here on this issue as it relates to MH370 http://www.fz.com/content/mh370-moto...board-ill-fated-flight-sources-say

So since I can't find an original source this widely discussed "fact"/rumour, it is not possible to take it much further, unless someone can find a better source that confirms this piece of information.

747megatop
Posts: 1750
Joined: Wed May 23, 2007 8:22 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting DTW2HYD (Reply 266):There was another suggestion these pings could be from a tagged fish. It appears tropical tuna is tagged and tracked until June in Indian Ocean. They use 34 Khz and 50 Khz transmitters.

In that case the pings picked up by Ocean Shield are very FISHY then. But, didn't analysts say that the pings were consistent with the ones emitted by FDR/CVRs ?

 Quoting DTW2HYD (Reply 266):One fine day either fishermen/surfers/beach-goers from Australia/Indonesia/Madagascar will find the first piece of debris.

In which case tracking it back to the exact source location would be next to impossible.

nupogodi
Posts: 933
Joined: Mon Mar 10, 2014 10:58 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting BaconButty (Reply 282):Don't mean to be argumentative (I like your posts) but the assumed 1km swath width is way too high. Which is why prebennorholm 's figures are way off. If you look at the specs of various auv integrated side scan sonars and they're an order of magnitude less in the likely frequencies we're talking about.

I figured, but as I said, I know *nothing* about sonar. I don't even like swimming. So I just run with the numbers people throw at me as long as we're doing estimates. The onus is on them!! :P
A man must know how to look before he can hope to see.

777Jet
Posts: 6977
Joined: Sat Mar 08, 2014 7:29 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting 747megatop (Reply 283):Quoting nupogodi (Reply 281): hey'll need to find another way to locate a search area. Which makes the statement - Finding the hay stack before finding the needle in the hay stack very true.

First they will need to find the farm and it seems as if they might not have even found the right farm yet
DC10-10/30,MD82/88/90, 717,727,732/3/4/5/7/8/9ER,742/4,752/3,763/ER,772/E/L/3/W,788/9, 306,320,321,332/3,346,359,388

dtw2hyd
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Joined: Wed Jan 09, 2013 12:11 pm

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting 747megatop (Reply 285):In that case the pings picked up by Ocean Shield are very FISHY then. But, didn't analysts say that the pings were consistent with the ones emitted by FDR/CVRs ?

Pundits gave several explanations for 33.5 Khz pings, ranging from weak battery, buried in silt, damage, ocean temperature...

 Quoting nupogodi (Reply 278):But really? \$200k/day? Jesus. So a 670 million dollar operation. Over 9 years. Good luck getting Malaysia to pay for that.

AUVs are not meant to search wide swathes, they are for narrow searches. AUVs also considered dual use tech. Malaysia only can pay for service thru US Navy. I doubt they can even buy.

High powered towed side-scan sonar is the best option. They are widely available, ship gets real time data. You can have several ships scanning in parallel from Perth to Banda Aceh.

nupogodi
Posts: 933
Joined: Mon Mar 10, 2014 10:58 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting DTW2HYD (Reply 288):High powered towed side-scan sonar is the best option. They are widely available, ship gets real time data. You can have several ships scanning in parallel from Perth to Banda Aceh.

Fascinating. USN's Orion is a towed SSS that can go to 6000m and has a swath width of 1800m when searching for aircraft debris in practice. It's slow, though, 1-3kt (probably closer to 1kt at 6000m).

An option, sure, but do you think a feasible one when we're talking about such large areas?

edit: If we assume 2nm/hr, 3.704km/hr * 1.8km = ~6.67km^2/hr, approximately 1.7 years to search 100,000km^2 going full tilt 100% of the time. Still seems impracticable.... And 100,000 is pretty conservative, no? But yes they could search in parallel... how much do these babies cost?

[Edited 2014-04-22 19:02:22]
A man must know how to look before he can hope to see.

LTC8K6
Posts: 1534
Joined: Fri Jun 05, 2009 8:36 pm

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting nupogodi (Reply 278):So a 670 million dollar operation.

I think the US Government has that amount of money fall out of it's pocket and get lost every month...

YoungMans
Posts: 432
Joined: Sat Mar 15, 2014 10:31 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting nupogodi (Reply 273):Such an operation might have scientific merit though...

Yes; you would end up with at least one section of the Indian Ocean that is well mapped.

markak
Posts: 43
Joined: Thu Mar 20, 2014 1:14 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

If they find the A/C in the next few weeks in the area they are looking, consistant with the INMARST ping ring, then we can conclude that the INMARSAT calculations were good and the sonar pings were the ULB.

But what if they don't find the AC in the area of the sonar pings after a reasonable time?

Then what was the source of the sonar pings that they initially heard for a day or two before the batteries supposedly died.

One might conclude that somone is trying to mislead the search effort and or the public for some reason.

And if that is true, then almost everything that we think is a "fact" becomes suspect.

Mark

nupogodi
Posts: 933
Joined: Mon Mar 10, 2014 10:58 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting MarkAK (Reply 292):One might conclude that somone is trying to mislead the search effort and or the public for some reason.

'One' might conclude that, but that doesn't "pass the razor" as people like to say here. They heard something, it was clearly man-made, it was approximately at the right frequency and nearly perfectly at the right interval. People here talk of tuna trackers but what is their ping interval? Do we actually have things in the ocean that behave exactly like aircraft ULBs?

Something down there was talking, and then it stopped. It's the best lead we've got.

I'd believe someone making a stupid mistake far before I believe a conspiracy theory.
A man must know how to look before he can hope to see.

BaconButty
Posts: 816
Joined: Tue Aug 06, 2013 3:42 pm

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting nupogodi (Reply 289):Fascinating. USN's Orion is a towed SSS that can go to 6000m and has a swath width of 1800m when searching for aircraft debris in practice. It's slow, though, 1-3kt (probably closer to 1kt at 6000m).

But at what frequency?

 Quote: Orion is a dual frequency (57/240 kHz) two body towed side-scan sonar system.

So presumably the 1800m is at 57khz. You might be able to spot a 60m airframe with that, it you're very, very lucky.
Down with that sort of thing!

LTC8K6
Posts: 1534
Joined: Fri Jun 05, 2009 8:36 pm

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

Yes, pingers seem to very common for all sorts of purposes. It's about time the problem was addressed, imo.

http://www.rjeint.com/acoustic_pingers.htm

http://www.rjeint.com/pdf/ULB-364RevE.pdf

nupogodi
Posts: 933
Joined: Mon Mar 10, 2014 10:58 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting BaconButty (Reply 294):So presumably the 1800m is at 57khz. You might be able to spot a 60m airframe with that, it you're very, very lucky.

I'm just going by what the Navy says on their site! 1800m swath width is what they deem acceptable in practice for searching for aircraft debris fields. As I said ... I know jack shit about sonar ... but hopefully the USN does.
 Quoting LTC8K6 (Reply 295):Yes, pingers seem to very common for all sorts of purposes. It's about time the problem was addressed, imo.

Heh, jeez, according to those links RJE will literally sell you an ULB that can perfectly sound like an ULB on CVR/FDR... Fascinating. Maybe aircraft ULBs can incorporate dual pingers at two separate frequencies, so you really couldn't mistake them for anything else ... but good luck convincing the rest of the world not to do the same for non-aviation purposes.

Disheartening to know these facts. If it's not the plane, I'd be interested to know in what they heard... Mystery after mystery.

edit: Remember though, ULBs were never meant to help locate the wreckage, just to help locate the recorders. Just now we have fancy technology that lets us go deeper, hear further, but still not really enough to search as wide an area as we'd want for acoustic pingers. So maybe just a dead end trying to engineer this problem away. Probably better to have better position reporting instead, while the thing is above water.

[Edited 2014-04-22 20:30:04]
A man must know how to look before he can hope to see.

747megatop
Posts: 1750
Joined: Wed May 23, 2007 8:22 am

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting MarkAK (Reply 292):And if that is true, then almost everything that we think is a "fact" becomes suspect.

If you ask me, the real "facts" so far

1) aircraft missing.
2) aircraft most probably did not go down in Gulf of Thailand as evidenced by lack of wreckage. (reason i say most probably is that there is a minute .001% chance that everyone goofed up and the aircraft is somewhere at the bottom of Gulf of Thailand.)
3) aircraft flew upto 7 hours judging by INMARSAT pings.
4) one of two possible arcs (Northern and Southern) as computed by INMARSAT pings. This is the weakest of the facts so far as this is more of a calculation rather than a fact. So, this calculation becomes a fact only after the wreckage is found.
5) unidentified pings found off Perth by Ocean Shield. Pings are from a man made object and seem to be consistent with FDR/CVR pings but not confirmed yet.

As simple as that. At most 5 facts since the saga began with56 thread (& counting). Right not all bets are off and probably the odds of finding the aircraft is the same as probably finding a solid gold bar buried in the sand dunes of Sahara Desert. (call me pessimistic but I am. I was more optimistic in the AF447 case since we at least knew the haystack in which we were searching for the needle. I hope my pessimism is disproved with regards to MH 370).

fotoflyer71
Posts: 41
Joined: Sun May 08, 2011 6:22 pm

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

 Quoting Pihero (Reply 263):And yes, six weeks after the event, it is bloody frustrating that the authorities - whoever they be - haven't come out with a preliminary report showing the slightes bit of information :

Try to learn from the mistakes of others. You won't live long enough to make all of them yourself.

jcxroberts
Posts: 97
Joined: Tue Mar 11, 2014 3:41 pm

### RE: MH370 Malaysia Airlines B772 Missing Enroute KUL-PEK Part 56

100 million is nothing for Malaysia (which has a large economy, actually) or a multi national like Boeing. Not to mention the insurance companies.

It would be catastrophic failure of governance to not find this plane because of 'lack of money', which is a bunch of b.s.
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