Beijing-bound MAS plane carrying 239 people missing as of 20 mins ago.

This debate is starting to sound like a ball game match, not so mutch facts and figures on both sides, just a difference of oppinion, to an avid believer of any given direction they will tend to follow what they are told and what is comfortable for them.

Zaphod58
reply to post by samuel1990

 

Really? Where's the AF447 debris still floating? Seat cushions are cloth, which means they absorb water. Cloth sinks after it's been in water for awhile. You have no clue what you are talking about.

No, no, no! Seat cushions are made from foam rubber, covered by cloth! Foam rubber never sinks.

samuel1990
I am so getting over this whole thing. I think something fishy is up (no pun intended) and I believe the black boxes have been dropped there. Where are the debris? For the poster whom said seat cushions would soak up water and sink and also that the plastic would be held down by currents - that's a joke.
There would be observable items in the water for years to come IF it had crashed there and it had not all been recovered.

Maybe that's what they (whoever created this saga) want, is for us to get bored with this story. Has the flight cargo list been supplied yet or are the authorities still holding back on that due to the suspicious items they were carrying?

I seem to be waking up to a new story on hat happened every day- and it's getting old...

Thoughts, anyone?

I concur wholeheartedly on the seat cushions. They are made from foam rubber. The stuff floats forever! Also there is the sprayed foam insulation throughout the aircraft. That will never sink either. I thought that's a well known fact.

Modern commercial passenger jets are made up of HUNDREDS of components that are designed to stay afloat after such an incident. Not for hours, but almost indefinitely.

reply to post by Mikeultra


Foam rubber absorbs water too. I've watched foam rubber that has gone over the side of a sailboat start to sink before we recovered it. And it weighed several pounds when it got back in the boat.

reply to post by weavty1


You mean like those "hundreds of components" that floated after SwissAir 111, Egypt Air 990, AF447, Flash Air, Silk Air, Adam Air?

Oh...wait...

reply to post by Zaphod58


Would the seat rubber sections be made from the same type of material as floatation devices like you get at swimming pools, the things you use to help keep you afloat?

reply to post by UKGuy1805


It's more like the foam that is in the pad you can buy for a chair.

reply to post by UKGuy1805

If it's standard foam rubber it's an open cell foam,which means the individual cells are all connected to each other and will soak up water and eventually sink.Bouyancy aids and life jackets are made from closed cell foam which means the individual pockets of air or cells are all isolated from one another so it can't soak up water.Coral is a natural open cell material,whereas cork is a natural close celled material.

Arbitrageur

roadgravel
At least you went with the 1 second interval.

I don't know the exact model of underwater beacon used on MH370, but here is an example specification sheet showing the following parameters which includes a ping interval of 0.9 pulses per second (a 1 second interval would be 1.0 pulses per second):

rjeint.com...

FAA & CAA approved under TSO-C121, the rugged and
durable construction of the DK120 insures its survival
even under high-impact shock. Once activated, the
DK120 will operate in water depths to 20,000 feet
(6000m). Using a 6 year user-replaceable battery, the
DK120 continuously sends out an acoustic signal for a
minimum of 30 days.

The DK120 is equivalent to Benthos (Datasonics) ELP-
362D Emergency Locator Beacon and is approved for use
by all major flight recorder manufacturers including
Honeywell Aerospace, GEC Marconi, L3 Communications,
Sfim Co., and Smiths Industries.

Operating Frequency 37.5KHz (± 1kHz)
Acoustic Output 160.5db ref 1 µ Pa @ 1m
Pulse Repetition Rate 0.9 Pulses Per Second
Pulse Length 10 ms
Activation Immersion In Salt Or
Fresh Water
Power Source Non-Haz Lithium Battery
Battery Operating Life
Stand-by (Shelf life) 6 years
Operating Life 30 Days
Operating Depth 20,000 Feet (6,096 m)

I couldn't remember the operating frequency tolerance but now I see it's +/- 1 kHz which means it's too loose to determine doppler shift from frequency alone, it would have to be determined from relative frequency when the ship travels in different directions, which they may want to try to figure out the direction the pings are coming from. Unfortunately the display on the pinger receiver system by the same manufacturer isn't accurate enough for doppler analysis because the display only shows "37.6":

www.rjeint.com/pdf/PRS275_DPR275.pdf

Once a signal is detected, the operator adjusts the sensitivity control for optimal directionality to determine the pingers true bearing and
then moves in the direction of the strongest signal.

I don't understand exactly what that means because I don't see how adjusting a sensitivity control gives direction, and apparently they are having a little trouble determining direction in the current search.

edit on 7-4-2014 by Arbitrageur because: clarification

The frequency stability window is indeed a problem.

With an emitter at 37500hz, and heading directly to the target, at 15knots,
in seawater at normal temperatures and salinity, the relative increase in frequency is 1khz.

Since the specs of the device are +/- 1KHZ, that is a +/- 15 knot error window.

For doppler to be of value here, they would have to identify what that center frequency really is. Whatever it really is would follow this ratio, but out of the box, it would be impossible to know until they CPA the target.

Addendum: Once you CPA the target, it gives you 2 ambiguous bearings 180 degrees apart. If that happens you reverse direction and travel
to the CPA and pick one of the bearings. If you get up doppler you immediately know that the bearing you are on is the correct one, otherwise you need to reverse course, and that is the proper bearing. Irregardless of the distance that you CPA, the center frequency will be known at that time. The ability to CPA here is the critical operation.

Zaphod58
reply to post by Mikeultra

 

Foam rubber absorbs water too. I've watched foam rubber that has gone over the side of a sailboat start to sink before we recovered it. And it weighed several pounds when it got back in the boat.

You must not have had real genuine foam rubber. All airlines that cross the oceans have to have floatation devices in them. If they're relying on inflatable types, they need to change over to pfd types like you wear in a boat.

reply to post by Zaphod58

There are HUNDREDS of different types, shores, etc, of 'foam rubber'...

The kind used and is strictly regulated for use on commercial passenger aircraft, is laminated and meant to be used as a floatation device. They are designed to remain buoyant for an almost indefinite amount of time.

That leaves anywhere from 305-440 seat cushions to be left afloat after such an incident. Not one has been found yet.

Why? Because MH370 didn't touch any body of water. It's on land.

Zaphod58
reply to post by weavty1

 

You mean like those "hundreds of components" that floated after SwissAir 111, Egypt Air 990, AF447, Flash Air, Silk Air, Adam Air?

Oh...wait...

Every single one of those had floating debris that were found and positively identified.
Yes, hundreds.

Diego Garcia put out a rush contract for a dry cargo ship on 03/31/2014 for "transportation, travel, and relocation" services to operate in the area between Singapore and Diego Garcia! So what are they transporting and relocating? Disassembled aircraft parts from MH370? Are they going to plant wreckage for the Ocean Shield to discover? The U.S. and Australia are close allies. I'm not sure I trust the Australian Prime Minister either, he seems very careful talking when he does his press conferences.
www.fbo.gov...

Mikeultra

carewemust
I go to bed last night and CNN has BREAKING NEWS that two distinct sets of "Pings" have been heard. It's now 17 hours later and CNN has BREAKING NEWS that two distinct sets of "Pings" have been heard.

Since this plane was lost, CNN has taken hundreds of hours to explain that no one knows where the flight 370 is at the moment. How does this TV Network earn any money?

Rothschild has very deep pockets. CNN doesn't have to earn any money. Their task is to spew propaganda 24/7! Over and over again.

Well, that it explains it Mikeultra. I could never work for a company that asked me to stay on the air being totally useless like CNN is forcing these anchors and "experts" to be. Thanks for the reply.
-cwm

Mikeultra
Diego Garcia put out a rush contract for a dry cargo ship on 03/31/2014 for "transportation, travel, and relocation" services to operate in the area between Singapore and Diego Garcia! So what are they transporting and relocating? Disassembled aircraft parts from MH370? Are they going to plant wreckage for the Ocean Shield to discover? The U.S. and Australia are close allies. I'm not sure I trust the Australian Prime Minister either, he seems very careful talking when he does his press conferences.
www.fbo.gov...

It's not there. Trust me.

BREAKING NEWS: The news idiots are speculating that the pinger signals are coming from a whale or maybe a volcano! I only listen halfway to keep up on the latest propaganda campaigns they are pushing. Whales and a volcano!

reply to post by Mikeultra


Absurd.
Second line.

reply to post by weavty1

How about Karachi? There's a giant PIA hangar building there. Lot's of past hijacking activity at that airport. Where on land do you think it might be?

Mikeultra
BREAKING NEWS: The news idiots are speculating that the pinger signals are coming from a whale or maybe a volcano! I only listen halfway to keep up on the latest propaganda campaigns they are pushing. Whales and a volcano!

Two weeks ago, there were some PINGS picked up and 3 days later a major earthquake hit off the coast of Chile. Perhaps what they're hearing are pre-earthquake audio of some type. Could open up a whole new era of earthquake prediction. Lots of important discoveries have been made by accident.