Malaysian Airlines MH370 contact lost

[Msunduzi]

Originally Posted by MountainBear

If I understand the complaint correctly, the complaint is based upon a fundamental error. The 40 degree arc that is plotted on a map is a two dimensional representation of a three dimensional reality. There is no claim that the plane moved along the 40 degree arc in two dimensional space, only that it moved along the arc in three dimensional space. If every ping happened along the 40 degree arc all the means is that the plane held to the same altitude for 7 hours, nothing more.

Either that or I do not understand the criticism.

The 40 degree "arc" has nothing to do with the plane's altitude.

If you plot a great circle map centered on the sub-satellite point, the 40 degree "arc" will be a circle.

Anywhere along that circle, the satellite will be 40deg elevation.

As the satellite is just under 35800 miles above the earths surface, the altitude of the plane will make a small difference to the elevation angle, and the effective circle under the plane on the surface would be marginally smaller than the 40deg circle on the ground.

Another way to look at the "arc" or circle, if you draw an imaginaru line from the sub-satellite point, through the satellite, and out into space, then positioned your self on that line far out past the satellite, then looked back at the earth with the satellite in the middle, the 40 degree "arc" would appear to be a circle, and the circles would get smaller until at 90deg, it is just a point.

[inchman254]

There is no claim that the plane moved along the 40 degree arc in two dimensional space, only that it moved along the arc in three dimensional space. If every ping happened along the 40 degree arc all the means is that the plane held to the same altitude for 7 hours, nothing more.

Let's get something straight. The arc that we are presented with has nothing to do with 40 degrees except it happens to be a 40 degree arc. And it has nothing to do with the path of the aircraft.

The arc is simply a line that marks the potential range of positions of the aircraft at a single, specific moment in time, based on a single ping from the satellite. It is the distance from the satellite computed based on the length of time from the time at which the satellite sends the ping until it receives the response. The aircraft's altitude would have very little effect on the position of the line... perhaps a couple of miles, but there is enough potential error that the altitude makes very little difference

The Inmarsat satellite does not have any azimuth information. The data that we are being presented with is simply a distance from the satellite at the moment of the last single ping. A radar works sort of the same way... the time it takes for the signal to return to the radar head determines the distance. The difference between radar and this type of information is that radar provides the azimuth (direction) of the signal based on the direction the radar antenna is facing at the moment the signal is received. RADAR stands for RAdio Direction And Ranging. All this satellite can provide is RANGE and that's all the arc represents.

Thank goodness they didn't present the arcs from the other pings. It would have been even more confusing.

[BOAC]

Zorin - you cannot dispute that the start (0111??) and finish (0811) were around that arc? Has the elevation for the intermediate pings been published?

[multycpl]

I take it that the search planes can fly in the dark !......So why take off at first light. If it takes 2 hrs to get onsite couldn't they leave 2 hours earlier ??


Sorry, I didn't get that the time change would be so great. I had guessed about 1 hour......seems I was wrong

[AndyJS]

I don't understand why they released information about the final "handshake" but not the others.

It would have made sense not to have revealed information about any of them for security reasons maybe, but once they released information about the 8:11 handshake it seems odd that they didn't do the same for the others.

[BOAC]

The arc that we are presented with has nothing to do with 40 degrees except it happens to be a 40 degree arc.

- had to chuckle there - that lightened up a heavy day!

[bono]

Chinese Satellite Objects Not Sighted By Aircraft

AMSA reports not sighting objects spotted by Chinese satellite. [Update#10]

"This evening China provided a satellite image to Australia possibly showing a 22.5 metre floating object in the southern Indian Ocean. AMSA has plotted the position and it falls within Saturday’s search area. The object was not sighted on Saturday.

AMSA will take this information into account in tomorrow’s search plans. "

Most likely the objects have floated away.

[Rory166]

ocean currents

Unlike the tidal currents for example in the north sea which are well known and predictable but always subject to variation such as due to weather. Ocean currents can only be predicted in terms of a long term average drift because there are rotational patterns which move generally in the direction of average drift. Consequentially the drift experienced on a particular day may be in any direction even counter to the long term average drift. This in no way can be extrapolated to previous or subsequent days.

When the search planes first arrived on scene bouys were dropped which will provide very interesting information. How useful will depend on the position relationship to any debris. Hopefully there are a significant number of bouys deployed over a wide area.

What is interesting is the dispersal power of the sea, if you observe two items close to each other it is often amazing to watch them drift apart.

There are particular area of the world where debris accumulates, if this sad saga does continue for many years it may be worthwhile stationing vessels in these area to analyse what turns up.

The BBC had a supposed expert on who postulated that because there is new satellite image 75 miles SW of previous then there is a 1.8 knot drift over the whole period (he failed to use the term knot) fortunately they have just now found an oceanographer who has strongly disputed this.

Rory

[oldoberon]

Originally Posted by BOAC

- ah - confirmed??? That's alright then. That would probably be the same minister who has changed tack just a few times?

I remain totally unconvinced so far of any 'stated facts' - except LKP and the 'essence' of the Inmarsat man's words. Everything else is 'subject to'. You, of course, are entiltled to believe all statements from Malaysia.

you must be the only person in the world who now does not accept they tracked MH 370 to the malacca straits. The minister quoted the data that allowed him to make that statement I just can't recall what it was, he wasn't telling us without evidence as you seem to imply.

Why do you think all the debate about did it go to the straits has stopped.

[BOAC]

you must be the only person in the world who now does not accept they tracked MH 370 to the malacca straits.

- actually, I think it quite a large club. You are obviously content. As I said, I 'accept' very little except LKP.

Why do you think all the debate about did it go to the straits has stopped.

- probably because if it is at the bottom of the South Indian Ocean it becomes slightly less relevant, does it not?

[jmjdriver1995]

I take it that the search planes can fly in the dark !......So why take off at first light. If it takes 2 hrs to get onsite couldn't they leave 2 hours earlier ??

The flight time from airbase to the search area is approximately 4 hours, not 2. The search planes are scheduled for take off at staggered times so as to keep at least one plane in the search area all or most of the daylight hours.

[Sober Lark]

If this was another Sully controlled landing in calm seas, the aircraft wouldn't be floating two weeks later.


If a fuel exhausted aircraft impacted the water from altitude then you just wouldn't have 22 metre pieces of debris still floating. Three metres at a push but not twenty two.

[oldoberon]

BOAC how did it get to the bottom of the southern ocean without crossing the peninsular.

the discussion about whether it was 370 crossing the peninsula stopped before the efforts to identify where on either arc it might be started.

You dip in every couple of days BUT don't read the interim posts, you admitted you only looked back 5 posts for something the other day.

if you don't read them all you won't be up to date.

Oh disbelieving everything that doesn't suit your view is pointless.

[oxo]

I take it that the search planes can fly in the dark !......So why take off at first light. If it takes 2 hrs to get onsite couldn't they leave 2 hours earlier ??

If you are using mk1 eyeballs to look for the debris, you don't want to be starting at dawn when there will be long shadows.

[GarageYears]

Collectively the ping arcs provide the "possible" track

Each time the ping occurred it defined a possible arc (i.e. the aircraft is somewhere on that arc? Right we've all got that?

The next ping will give us another arc, the difference between arcs reflects the distance traveled. The aircraft has a minimum and maximum speed that allows the plane to move to the next arc. However the overall distance traveled to the last ping tells us the average speed, and I think we all agree it's unlikely to have done much other than cruise at this average speed...

So, collectively each arc and the next give us a track, right? If the arc doesn't change from one ping to the next the aircraft was either traveling along that arc or intersected it again, or was stationary. The over distance traveled/time will reveal whether the idea the aircraft was stationary at any time seems plausible - personally I doubt it.

Can anyone tell what is wrong with the above?

[RichardC10]

AndyJS

I don't understand why they released information about the final "handshake" but not the others.

It would have made sense not to have revealed information about any of them for security reasons maybe, but once they released information about the 8:11 handshake it seems odd that they didn't do the same for the others. I don't understand why they released information about the final "handshake" but not the others.

It would have made sense not to have revealed information about any of them for security reasons maybe, but once they released information about the 8:11 handshake it seems odd that they didn't do the same for the others.

The final handshake/ping data had to be released to convince everyone that the aeroplane was far South (or North) and definitely not in the South China Sea. After that there was no benefit to the investigators in releasing extra information, it would just lead to more spam in the e-mail accounts of NTSB, Boeing, Inmarsat, the Malaysian Authorities etc. etc.

[Zorin_75]

Originally Posted by BOAC

Zorin - you cannot dispute that the start (0111??) and finish (0811) were around that arc? Has the elevation for the intermediate pings been published?

I do and it hasn't.

[oxo]

The next ping will give us another arc, the difference between arcs reflects the distance traveled.

Nope, because you don't know what point the plane was on for any of the arc.

All you can tell by consecutive arcs is what component of the track was toward or away from the satellite.

If you know the speed, then using simple geometry, you can then calculate the other component, and that will then give you a position relative to the previous ping.

I assume this is how the NTSB decided on the location in the southern ocean.

[BOAC]

Originally Posted by oldb

you admitted you only looked back 5 posts

- I invite you to 'look back'? I believe I said 5 pages.

Originally Posted by RichardC10

The final handshake/ping data had to be released to convince everyone that the aeroplane was far South (or North) and definitely not in the South China Sea.

- please explain that assumption. Why could it not be ANYWHERE on the arcs? What specific information would be available to position the ping at the extremes?

A further puzzle - the Inmarsat man said that during the 7 hours the 'pings got longer', yet they started around the 40 and finished around the 40. Huh?

[kappa]

Missing jet WAS carrying highly flammable lithium batteries: CEO of Malaysian Airlines finally admits to dangerous cargo four days after DENYING it
MH370 WAS carrying highly flammable lithium batteries admits CEO of Malaysian Airlines | Mail Online

How does this affect the thinking on the ‘cause’ of this aircraft being missing?