Missing Airliner

[kwselke]

Here's a question. How can this "new map" that's being cited all over tv and the internet possibly be accurate?

https://twitter.com/Duenes/status/444894409943822336/photo/1

For example. The red radial line is supposed to define where the airplane may have flown to 7 1/2 hours after takeoff. Ok. How then is it possible to take the same amount of time to fly to Laos as it would to Kazakhstan? Shouldn't the radial lines be equal distance from the point of origin as opposed to centering the satellite for this possible final fix? Or am I missing something here?

The map does not denote where the plane could have flown to, I denotes the probable locations of where the last 'ping' came from. The 'pings' would have continued if the plane was on the ground and its engines running. The northern arc would have taken the plane over highly militarized borders and probably would have caused the scrambling of interceptors. The thinking is the southern arc is the most likely area to search.

 

[moe smith]

I think it has more to do with the orbit of the satellite(s?) and its (their?) field of view. The satellite receiver has an omnidirectional antenna, so it cannot determine the angle of arrival. However, put together the sightlines of the satellite and the fuel and range of the aircraft and those are the lines you get.

None of that would change the distance needed to be traveled by the airplane to end up at any point on that red line 7 1/2 hours after takeoff though. The point of origin is what matters. Time and distance are to be equal from the point of origin if they are assuming the speed is the same. According to that illustration, they're not. Do you see what I mean?

 

[moe smith]

The map does not denote where the plane could have flown to, I denotes the probable locations of where the last 'ping' came from. The 'pings' would have continued if the plane was on the ground and its engines running. The northern arc would have taken the plane over highly militarized borders and probably would have caused the scrambling of interceptors. The thinking is the southern arc is the most likely area to search.

So what you're saying is the extreme northwestern end of the red line is the furthest that airplane could have traveled 7 1/2 hours after takeoff, and any point closer to the point of origin down that line was a result of the plane being on the ground, going slower than projected, or circling for a period of time, accuracy of fix approximate of course, given the lack of a second or third intersecting line of position. Am I understanding you correctly?

 

[Old TexMex]

I heard an expert say perhaps it was landed at a remote, secluded, super secret field, dismantled, put on a ship to be re-assembled and equipped with a nuke.
Wow, James Bond (or Maxwell Smart) please stand up....

 

[TucsonMTB]

That looks like way too much area to search for a crashed airliner effectively.

 

[kwselke]

So what you're saying is the extreme northwestern end of the red line is the furthest that airplane could have traveled 7 1/2 hours after takeoff, and any point closer to the point of origin down that line was a result of the plane being on the ground, going slower than projected, or circling for a period of time, accuracy of fix approximate of course, given the lack of a second or third intersecting line of position. Am I understanding you correctly?

I'm definitely not an expert, but you are getting my understanding of what the arcs on the map mean. My understanding is the pings were at one hour intervals and the arcs were calculated based on the amount of deflection the geosynchronous satellite's antenna would have needed to recieve a perfect signal on the last ping. If the plane flew for another 45 minutes after the last ping nobody knows. They're playing find the needle in a haystack and trying to make the haystack a bit smaller.

 

[Old TexMex]

And then there's...Who?

 

[Road Rat]

I heard an expert say perhaps it was landed at a remote, secluded, super secret field, dismantled, put on a ship to be re-assembled and equipped with a nuke.
Wow, James Bond (or Maxwell Smart) please stand up....

The TV monitor is overrun with talking heads pretending to be experts.

Best I can tell absolutely no one has a clue and they are working things out - one step at a time.

I'm still going to wait for the movie!!!

 

[moe smith]

I'm definitely not an expert, but you are getting my understanding of what the arcs on the map mean. My understanding is the pings were at one hour intervals and the arcs were calculated based on the amount of deflection the geosynchronous satellite's antenna would have needed to recieve a perfect signal on the last ping. If the plane flew for another 45 minutes after the last ping nobody knows. They're playing find the needle in a haystack and trying to make the haystack a bit smaller.

I'm not sure about deflection, as I'm not familiar with how this "ping" system is structured. I would think a simple time difference could be worked out to establish an arc, the way LORAN was set up for example with TDs. The more "stations" or satellites you're communicating with the more accurate the fix is, all based on the amount of time it takes to receive the signal (ping), attitude or direction of antennae being irrelevant.

 

[smokindog]

What could we do to get these media heads to put the same amount of effort into things like Benghazi????

 

[kwselke]

I'm not sure about deflection, as I'm not familiar with how this "ping" system is structured. I would think a simple time difference could be worked out to establish an arc, the way LORAN was set up for example with TDs. The more "stations" or satellites you're communicating with the more accurate the fix is, all based on the amount of time it takes to receive the signal (ping), attitude or direction of antennae being irrelevant.

My comments were based on NY Times and Washington Post articles. Here what I just read from CBS News:

The signal, called a "handshake" does not transmit data, but just tells the satellite that the plane is still in the sky. Once an hour for four or five hours, the plane communicated with a satellite, according to a U.S. official speaking on background. Then the communication stopped - the plane either crashed on land or in the water, or it landed somewhere and turned off the engines.

The communications back and forth do not give a specific location for the plane. But they indicate the direction the satellite would have to tilt its antenna to find the plane though not where on that arc the plane would be.

 

[moe smith]

My comments were based on NY Times and Washington Post articles. Here what I just read from CBS News:

The signal, called a "handshake" does not transmit data, but just tells the satellite that the plane is still in the sky. Once an hour for four or five hours, the plane communicated with a satellite, according to a U.S. official speaking on background. Then the communication stopped - the plane either crashed on land or in the water, or it landed somewhere and turned off the engines.

The communications back and forth do not give a specific location for the plane. But they indicate the direction the satellite would have to tilt its antenna to find the plane though not where on that arc the plane would be.

I take everything most news outlets say with a grain of salt, especially on this story, but if that's true I find that interesting. I'd think that would be a pretty inefficient way to communicate in that it would make handling multiple targets at the same time antennae movement intensive, if not impossible.

 

[kwselke]

I take everything most news outlets say with a grain of salt, especially on this story, but if that's true I find that interesting. I'd think that would be a pretty inefficient way to communicate in that it would make handling multiple targets at the same time antennae movement intensive, if not impossible.

I was only trying to explain the arcs on the map. The system they are using was designed to report things like the toilets are in need of a vacuum truck upon landing, not for monitoring plane location. It was such a little used system that pilots have commented they did not know it existed on planes that did not subscribe to the service. I only believe bits and pieces of what is coming out too.

 

[LVSteve]

None of that would change the distance needed to be traveled by the airplane to end up at any point on that red line 7 1/2 hours after takeoff though. The point of origin is what matters. Time and distance are to be equal from the point of origin if they are assuming the speed is the same. According to that illustration, they're not. Do you see what I mean?

Yes, but that could well be the geometric distortion caused by the map projection. Typical map projections make places North and South of the Equator look larger than they are. KL is only 3° North of the Equator, but when contact was lost the plane was a lot further North, meaning if it turned back it has to fly "over the hump" of the Equator. That is why the Southern line appears shorter.

What the media and most commentators are failing to explain is that those lines represent the furthest the plane can be away from the satellite before loss of signal. Somehow they seem to be assuming that the plane flew out of satellite coverage. The truth is the signals could have been turned off by pulling the breaker or crashing at almost any location West and South of those lines. That is a buttload of real estate/empty ocean almost down to Antarctica. Unless somebody recently put in an airport on Heard Island or Kerguelen, that plane is gone.

 

[moe smith]

What the media and most commentators are failing to explain is that those lines represent the furthest the plane can be away from the satellite before loss of signal.

I'm not sure that's quite right and yes, it's confusing. See the dialogue between kwselke and I. The plane shouldn't be inside of that line but somewhere along it, with the caveat that it could be inside or outside a slightly expanded area of those lines, depending upon which way it traveled, or when it came to a stop in relation to the time it wasn't reporting between pings. (ie:45 minutes until the next handshake)That distance would potentially be added to the circumference of the line along the line at it's last reported position, wherever that was.

 

[kwselke]

I'm not sure that's quite right and yes, it's confusing. See the dialogue between kwselke and I. The plane shouldn't be inside of that line but somewhere along it, with the caveat that it could be inside or outside a slightly expanded area of those lines, depending upon which way it traveled, or when it came to a stop in relation to the time it wasn't reporting between pings. (ie:45 minutes until the next handshake)That distance would potentially be added to the circumference of the line along the line at it's last reported position, wherever that was.

The first of those maps I saw this morning emphasized the concentric rings to either side of the red arcs more than the map posted here. I assumed the search area would need to be one ring in and one ring out from the red. That is one huge area, but it does eliminate a huge area too.

 

[cmort666]

It would depend on your definition of success. It certainly failed to reach it's original destination which, if hijacked, certainly could be portrayed as a win for the hijackers. They've taken credit for fires, floods, tornadoes and hurricanes, why the silence here?

If the Chinese shot it down over China, you'll probably NEVER hear anything, from them OR whoever (if anybody) sent the supposed hijackers.

If it were shot down, the supposed planners would have no more idea where the plane is that any of US.

And if the Chinese shot it down, the optimum outcome is for NOBODY (besides them) to EVER know. For them, this is like the Japanese balloon bomb campaign against the United States. Between the failure of their instrumented telemetry balloons, our shooting down of many of the rest, and our total media blackout, the Japanese were left totally in the dark as to the actual effectiveness of the attacks.

And NEVER forget that the Chinese government would rather shoot down a HUNDRED airliners and kill a THOUSAND Chinese (never mind Malaysians or Americans) than suffer ANY sort of embarrassment at the hands of opponents of the regime, ESPECIALLY those whom they consider ethnically inferior.

 

[LVSteve]

I'm not buying that the satellite tilts its antenna to follow individual aircraft. Unless the antenna on the satellite uses some kind of scan of a very wide beam, I suspect those lines are just the practical limits of reception given the antenna patterns of the satellite and the aircraft. The satellite is looking down over one spot and the aircraft antenna is looking largely straight up. The further away you get from straight up and down, the less likely you will receive the signal. The curvature of the Earth alters the look angle of the aircraft antenna as it moves relative to the satellite.

Short of timing the pings like a secondary radar or IFF, there is no way to determine where the plane was within the satellite's view except by knowing where it started and computing possible speed, course and fuel. IF the game is that they DO time the pings but there is no angle information, then the plane WAS on one of those red lines when the signal was lost. Simple laws of radio propagation and physics rule.

 

[moe smith]

The first of those maps I saw this morning emphasized the concentric rings to either side of the red arcs more than the map posted here. I assumed the search area would need to be one ring in and one ring out from the red. That is one huge area, but it does eliminate a huge area too.

It also pretty much ensures that if the plane is north of the point of origin, it's on land. That's a huge development. If it went south, they went for a swim..

 

[kwselke]

It also pretty much ensures that if the plane is north of the point of origin, it's on land. That's a huge development. If it went south, they went for a swim..

Since day one I suspected Myanmar/Burma as a possible landing point. The revalation the the plane hit 45,000 feet (2,000 above a 777 service ceiling) at the turn point makes me suspect whoever was piloting was on oxygen and was trying to incapacitate the others on board. I have no idea how much control over cabin pressurization a pilot has, but 45,000 feet without oxygen will put an insurrection down fast.