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Malaysian Airlines MH370 contact lost

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Old 5th May 2014, 01:07
  #10441 (permalink)  
 
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Originally Posted by MrPeabody
The APU will then attempt an auto-start with whatever fuel is left in the APU fuel manifold and left fuel tank. If the APU were to start (it wouldn't be for long); the buses would come on line again and SATCOM would power up and attempt to reacquire the satellite.
I believe this is the main circumstantial evidence for believing the aircraft was out of fuel at that time, and should be somewhere near that location. Which seems to be consistent with the current search area.
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Old 5th May 2014, 02:07
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The JACC has already stated the revised underwater search zone could be up to 700km (378NM) long - thus indicating the greatest area of uncertainty is just how far the aircraft travelled before it went in - because the aircraft speed and altitude on its last leg is nothing more than a WAG.
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Old 5th May 2014, 03:24
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A panel of international aviation and SAR experts from around the world will convene in Australia's National capital Canberra, this week, to go over all the previous information, calculations and assessments, to see if anything new can be added to it, and to try and further refine the current position of the aircraft.

The report produced by this panel will be handed to the independent underwater contractor hired by the three countries who are the search leaders - Australia, Malaysia and China.

Interestingly, the Chinese are refusing to wait for any private underwater contractor to be be hired, and are sending their own underwater search technology and ship to the search zone this coming Saturday, to continue to try and find the aircraft.
This rather secretive Chinese vessel is only defined as "Navy vessel 872, with strong underwater search capabilities".
There are apparently requests by some Chinese experts for the Navy to utilise the Chinese manned Jiaolong submersible, which has extreme depth capabilities - 7000M (22,965') - but there is no official indication at this point, that the Jiaolong will be used.
One would tend to define the Chinese efforts as "gung-ho", but that's the Chinese way.

MH370 search area to be reviewed

Last edited by onetrack; 5th May 2014 at 04:23. Reason: addendum ..
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Old 5th May 2014, 04:31
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Australia's Deputy PM, Warren Truss has outlined the need for more seabed mapping to be carried out in the search zone, as a joint meeting of the three countries involved, concluded today.

Truss has also revealed the JACC HQ will be relocated to Canberra, instead of Perth, "to bring the centre closer to the high-level representatives of Malaysia and China and other countries who are interested in the search".

MH370 search area to be expanded
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Old 5th May 2014, 05:02
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Thanks for that snippet of info Onetrack.

Am somewhat bemused by the JACC statement that the revised underwater search zone could be up to 700km (378NM) long. How can this tally with the CVR/FDR transponder pings picked up by the towed array and their reportedly short range? It either puts the provenance of these detections in doubt or implies they are being advised by experts that these high frequency acoustic signals can be channeled over greater distances.
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Old 5th May 2014, 06:50
  #10446 (permalink)  
 
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Interesting that JACC is referring to the Inmarsat data as the "best information we have."

That comment seems to be downplaying the significance of the pingers heard.

In addition, the sharply revised estimate for the size of the search area seems to throw significant doubt on the pingers (surely this frequency can't transmit over many hundreds of km).




MH370: Countries vow to continue search

Date May 5, 2014 - 4:06PM
David Wroe

National security correspondent



Chinese, Malaysian and Australian ministers have met in Canberra, announcing a new phase in the search for MH370.




Australia and other countries involved in the search for missing flight MH370 remain confident they are hunting in the right area and are embarking on a global push for new search equipment.
Transport Minister Warren Truss, after meeting with his counterparts from Malaysia and China, vowed the search would continue though he admitted there was no telling how long it would take. Just to find and acquire the equipment for the next phase would likely take four to six weeks, he said.
“We obviously have no idea when it’s likely to be found. You just always hope it’s tomorrow. So far our very, very best leads – days when we were quite confident that this was going to be the day – have all proved fruitless,” he said.
Malaysian Acting Transport Minister, Hishammuddin Husssein, Deputy Prime Minister Warren Truss and Chinese Transport Minister, Yang Chuantan address the media after their meeting on the search for MH370 at Parliament House in Canberra. Photo: Alex Ellinghausen




International experts would meet in Canberra on Wednesday to sift through the information gathered so far in a bid to define the new search area and make sure nothing has been missed, Mr Truss said.
This audit of information would “look again at the satellite information that has been accumulated so that we can make sure that it's been accurately interpreted (and) whether it should lead to some further search for information”, Mr Truss said.
Former chief of the Defence Force, Angus Houston, who is heading the search, said: “I still think that that is the best information we have” but added it was sensible to go back over the data to “make sure there are no flaws in that”.
A key part of this week’s meeting will be identifying the equipment needed – largely sonar devices that can be towed behind a ship and submersible vehicles to search the sea floor.
Mr Truss said there were only a “handful” of such assets around the world, most of which are in the private sector. Authorities have begun a tender process so that companies could bid to supply the equipment.
Also, most of the ocean floor in that area had never been mapped and was therefore little understood.
“It will require a significant effort for us to understand the ocean floor in that area,” Mr Truss said.
“I should emphasise that there are only a handful of relevant pieces of machinery in the world … but we know that some countries have oceanographic vessels that are capable of mapping the sea at that depth, and hopefully we will be able to harness some of that equipment to get on with that job.”
Chinese Transport Minister Yang Chuantang vowed the search would not let up.
“We will continue to search in accordance with the consensus reached at this meeting and assure that the search will not be interrupted, not be suspended, not be given up and not be slacked,” he said.
On the question of the cost of the ongoing search, Mr Truss said the expected $60 million price tag would be discussed between the participating countries.
Malaysian Transport Minister Hishamuddin Hussein added that none of the countries involved had so far raised the matter of costs with Malaysia, and added that there was now “a good platform for others to come forward and participate”.
So far, each country involved has borne its own costs. But Mr Truss said Australia would be looking for increased involvement from companies such as Boeing – which made the 777 plane – and Rolls Royce – which built the engines – and their host countries.

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Old 5th May 2014, 07:06
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https://au.news.yahoo.com/thewest/a/...-interference/

The disappearance of Malaysia Airlines Flight MH370 could have only involved human input, according to two aviation experts.

A senior Boeing 777 captain and a former crash investigator agreed that given the information outlined in the preliminary report issued late last week, "human input was essential" for the MH370 to end its flight in the Indian Ocean.
Comments from qualified airline pilots (preferably Boeing 777) would be welcome, please.
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Old 5th May 2014, 08:45
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A panel of international aviation and SAR experts from around the world will convene in Australia's National capital Canberra, this week, to go over all the previous information, calculations and assessments, to see if anything new can be added to it, and to try and further refine the current position of the aircraft.
This is good news, as an Analysis of the MH370 Preliminary Report by an independent ATM consultant and an Engineering Fellow with Raytheon Company raises questions about the current search location, including:
The displayed initial estimated point seems somewhat inaccurate, as it implies that the aircraft performed a turn to the NW immediately after leaving radar coverage. On the basis of the presented information, it seems much more likely that the aircraft would have continued on its heading and that the initial satellite point should be located further south.

This would potentially have the effect of skewing the entire estimate satellite trajectory (and thus any impact point) by a number of miles.
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Old 5th May 2014, 08:52
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1) Lithium batts may have burned thru transponder feed and created toxic gas before burning out/being extinguished,and the pilot was trying to head back to KL before being overcome by gas.

2) IF there had been that amount of gold on board and there was a suspicion that it'd been hijacked then we WOULD NOT have all those ships/subs in the southern ocean - the authorities would have come out and laid their cards on the table from the start
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Old 5th May 2014, 09:24
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Originally Posted by Robin Clark
Further to my #10413 .......did some trig. and found that the satellite should have been on a bearing of 73.17 degrees to port as MH370 was on climbout ........so in fact they were flying partly toward the sat. so it looks increasingly likely that Inmarsat got it wrong and their chart is actually indicating the opposite sense......ie .up is towards the satellite , increasing any doppler shift .....and vice versa......
The INMARSAT satellite geolocation is over the equator on the Africa side of the center of the Indian Ocean. MH370 was climbing out of Kuala Lumpur towards Vietnam heading North East - away from the satellite. It was in the fringes of the cover of the Pacific INMARSAT satellite but had set up a connection with the Indian Ocean INMARSAT satellite. They only started flying toward the Indian Ocean satellite after breaking radio contact and turning back.
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Old 5th May 2014, 10:58
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Originally Posted by Ian W
They only started flying toward the Indian Ocean satellite after breaking radio contact and turning back.
As Robin Clark pointed out in his post on this subject, the aircraft on initial climb out had the satellite at - 73.17° (to the left), which meant that any Doppler shift with reference to the Inmarsat 3-F1 satellite would be increasing.

However, that is not the end of the story, as it is the aircraft that senses the Doppler shift between it and the satellite and shifts its Tx frequency to compensate. If flying toward the satellite it would shift its Tx frequency downward so that any transmission from the aircraft would arrive at the satellite at the assigned and expected Rx frequency. Likewise when flying away from the Satellite, the Doppler shift would be deceasing and the aircraft would adjust its Tx frequency in the opposite direction, i.e. upwards.

The satellite has nothing to do with the Doppler correction; that is assigned to each individual aircraft, otherwise the satellite would have a very large job on its hands when communicating with many aircraft. What the Satellite does do, is transmit a constant carrier on the P Channel which the aircraft uses to sense the received frequency offset from the assigned channel and then adjusts its Tx channel(s) in the opposite direct to compensate.

Any Doppler shift between the the Ground Station (GES) and the satellite is corrected at the earth side, which allows the separate isolation of Doppler between the Sat and the aircraft (AES).

Now start thinking about where this "burst frequency offset" info is coming from.

Last edited by mm43; 5th May 2014 at 20:03. Reason: changed the order of a couple of words
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Old 5th May 2014, 12:22
  #10452 (permalink)  
 
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How will analysis of the last search phase affect the next?

Porker1 said
Am somewhat bemused by the JACC statement that the revised underwater search zone could be up to 700km (378NM) long. How can this tally with the CVR/FDR transponder pings picked up by the towed array and their reportedly short range? It either puts the provenance of these detections in doubt or implies they are being advised by experts that these high frequency acoustic signals can be channeled over greater distances.
and
Heathrow Flyer (quoting an independent Raytheon assessment of Inmarsat data) said:
The displayed initial estimated point seems somewhat inaccurate, as it implies that the aircraft performed a turn to the NW immediately after leaving radar coverage. On the basis of the presented information, it seems much more likely that the aircraft would have continued on its heading and that the initial satellite point should be located further south.

This would potentially have the effect of skewing the entire estimate satellite trajectory (and thus any impact point) by a number of miles.
This would tend to agree with the hypothesis that Ocean Shield's limited and non-continuous pinger detections were genuine (but distant) second or even third "convergence zone" in origin. Sound propagation in deep water tends to be distorted by thermoclines in the depths (abrupt changes of temperature at different levels in deep water (aka layering)). It tends to cause large amplitude focussed ripples in detected acoustics (i.e. an erratically moving incomplete annulus every 30 to 50 miles or so - at or near the surface). Accomplished and experienced sonar operators can tell the difference between first, second and third convergence zones. This effect for a sea-bottomed "pinger" might also be focussed in a particular direction by the ocean bottom's topography (think of MH370's pinger being inside a deep valley with its pinger's acoustics being channelled in the direction of the valley or canyon's mouth). Ocean hydrographers cannot predict or allow for these geomorphic effects and time-warps in detected ensonification. It's at the same time both diffraction and refraction via its water-routing - and for a bottomed object, reflection. The phenomenon is a great friend of submariners as it can cloak their actual position even when making noisy high-speed progress. All they need do is "hide" beneath a layer and noisily propagate in all directions. After swamping all listening sonobuoys and fixed arrays with their high-speed sound signature, they then slow and go to a silent undetectable loiter mode. Concentrating an MH370 sonics search within the immediate area of a few pinger detections was overly optimistic and seems to have disregarded the characteristics of sound in deep water.
Add in the Raytheon claimed discrepancy and it's still a much larger and indefinite search area than those you see on the AMSA/JACC charts. I guess we will see whether this will be reflected in the next phase search zone prognostications.

It's worth noting as far as range of detection goes, that a blackbox pinger's job is to be heard, whilst a submariner's intention is never to be heard - yet, in my experience, long distant detections during aerial ASW sonics search was the norm for conventional snorting and/or nuclear boats (particularly the Soviet Echo II boats and later).

Desert 185 said:
Unctuous:

Ref O2 fire...If you think this is a possibility, nowhere in the checklist does it say turn off the transponder and/or the ACARS, and do not talk to ATC, to include not declaring a emergency.
Fair comment for a mere nasty brown smell, but does not reflect what an injured crew might do after/during a sudden oxygen flare. There's no oxy on/off valve on the flight-deck and someone blinded by flame might just think that instantly killing the electrics might bring relief - from what is essentially a brief explosion and subsequent fireball. You only have to look at the cockpit photo of the MS 777 "Nefertiti" scorching to grasp that. I'd be surprised if they (or any surviving "he") didn't bale to the cabin immediately. But I'd also not be surprised if they were cooked where they sat.

Last edited by UNCTUOUS; 5th May 2014 at 13:27. Reason: afterthought
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Old 5th May 2014, 12:38
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Unctuous... Excellent post.

I was wondering if the depth etc of the actual receiver would negate any of these anomalies.

I would have thought that if the receiver was virtually on top of the pings then that should give an accurate position. I would assume that IF the boxes are actually there then the receiver would have passed pretty close to one of them.

Of course does not necessarily mean the aircraft is there as well, which is probably why the are having so much trouble locating them with the UAV.
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Old 5th May 2014, 12:42
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Point taken on the deep water ping progagation.

But the spectrum/waterfall of the recorded pings looked pretty clean. Except that the detected frequency was so offset by 4.2 kHz from 37.5 kHz.

The area searched was about 15 NM x 15 NM around the ping that was heard for 2 hours and 20 mins(!!). Do you think propagation can go beyond this?
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Old 5th May 2014, 12:43
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Human intervention ....

Quote:
The disappearance of Malaysia Airlines Flight MH370 could have only involved human input, according to two aviation experts.

A senior Boeing 777 captain and a former crash investigator agreed that given the information outlined in the preliminary report issued late last week, "human input was essential" for the MH370 to end its flight in the Indian Ocean.
Comments from qualified airline pilots (preferably Boeing 777) would be welcome, please.



Val'd....
For the jet to leave it's programmed waypoint to waypoint flight plan to China;stored in the flight management system; under normal conditions would have required a human to intervene.
1. A pilot could take the controls manually, click the autopilot off and hand fly the jet whatever direction or altitude.
2. A pilot could modify the upcoming legs in the active flight plan to have the autoflight system steer the jet to new waypoints.
3. A pilot could build a second flight plan in the second flight management computer, activate and execute the second flight plan and either hand fly or direct intercept a waypoint on the new flight plan.
4. A pilot could leave the autopilot on, but steer to whatever heading via heading select mode.

On "my" 777's, the company dispatch center can send via data link; new flight plans, to the inactive flight management computer system. To my knowledge, only a human actually on the flight deck of the aircraft could activate and execute such secondary flight plan.

Whatever capability an outside agency (human) might have to activate a secondary flight plan is unknown......
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Old 5th May 2014, 13:22
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The independent report on the ICAO publication

Ref: Steve Winter’s report at:

Analysis: MH370 Preliminary Report | Air Traffic Management | Air Traffic Management - ATM and CMS Industry online, the latest air traffic control industry, CAA, ANSP, SESAR and NEXTGEN news, events, supplier directory and magazine

It’s not my job to act as cheerleader for the analysis we have from the International Panel but Steve Winter has raised some points that I believe can be understood on the basis of the published data, so I offer the following comments:

I have edited the extracts of the report for length.
The first satellite “ping” occurred only five minutes after the last air defence radar contact at 02:22 MYT, so the estimated satellite position is quite tightly constrained….On the basis of the presented information, it seems much more likely that the aircraft would have continued on its heading and that the initial satellite point should be located further south … skewing the entire estimate satellite trajectory (and thus any impact point) by a number of miles.
I was also surprised that the turning point could be so tightly defined on the basis of the data to hand; as plotted it may reflect a best fit to all the ping-arc data, with the North/South constraint of the 18.30 ping-arcs. However, as I have proposed in previous posts, it is the value of 00:11 BFO that sets the final red-zone search area along the 00:11 ping-arc, not the overall course/speed from the ping arc data (at least in the case of level flight at 00:11). The 00:11 BFO has a latitude dependence via component D2.
The maps also show the probability areas for the aircraft impact, corresponding with the final “ping” at 08:19 MYT. The areas are shown as the “Highest Probability Area” to the north, centred on the Zenith Plateau which was the focus of the initial underwater search; the “Lowest Probability Area” to the south of that, and finally, the “Mid Probability Area” to the south of that. This seems curious, as a simple probability distribution would be expected to have the “Mid Probability Area” adjacent to the “Highest Probability Area”. Perhaps this is a typo, but it also makes one wonder why there is no probability area to the north of the Highest Probability Area.
Again as I have proposed before, the high-probability area is set on the basis the aircraft was level at 30000ft at 00:11 so there was no effect of descent rate on the BFO. The width of this zone is set by the total statistical uncertainty. The maps show different heights for the three probability areas, the writer seems to have missed this.

There is no marked area to the North of the red-zone as any climb from 30000ft at 00:11 was regarded as improbable (climb shifts the area North).

This all indicates that further refinement of the satellite data would be useful and that the final resting place of MH370 may well be within a much wider search area.
Further thought since the last post on the differentiation of the red/green/yellow zones. If a descent is allowed as an option at 00:11, then the final BFO value loses most of its value for setting the speed (and hence course) – the mixture of position and descent contributions cannot be disentangled in one measurement. If there was any BFO measurement from the 00:19 partial pings they would be similarly affected as the aircraft would be descending steeply, since 00:19 is generally attributed as the fuel exhaustion point.

With the 00:11 point discounted for this purpose, the selection of the speed/course drops back to the earlier ping-BFO values. The mid-probability/green area may reflect the best fit to these data points only. With a speed/course selected on this basis the 00:11 ping then gives a predicted descent rate. However, the earlier BFO data must have lower value in setting the speed/course in this situation so the predicted area of search might get quite wide (and more so if the initial turning point is not pinned down accurately). The aircraft analysis based on possible autopilot modes/aircraft configuration may constrain the possible descent rates at 00:11 and so still provide some limit in the Southern direction particularly (which corresponds to higher descent speeds).
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Old 5th May 2014, 13:58
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With thanks to SKS777FLYER:
For the jet to leave it's programmed waypoint to waypoint flight plan to China;stored in the flight management system; under normal conditions would have required a human to intervene.
1. A pilot could take the controls manually, click the autopilot off and hand fly the jet whatever direction or altitude.
2. A pilot could modify the upcoming legs in the active flight plan to have the autoflight system steer the jet to new waypoints.
3. A pilot could build a second flight plan in the second flight management computer, activate and execute the second flight plan and either hand fly or direct intercept a waypoint on the new flight plan.
4. A pilot could leave the autopilot on, but steer to whatever heading via heading select mode.
OK, that takes care of Nav (i.e. path over the ground/sea). The route followed could all have been input to the FMS and handed to the automatic flight system ('autopilot') at the time of deviation from the original route to Bejing. No further human input to Nav would have been necessary. Everyone on board could have been dead from that point onward and the route over the ground/sea would still have been flown.

However, could a vertical 'profile' to match the claimed visits to (lets assume) 39000ft and 5000ft be input to the FMS, handed to the automatic flight system ('autopilot') at (let's assume, for ease of discussion) the time of deviation from the original route to Bejing and thereafter be followed by the aircraft without further human intervention?

In other words, after input of the profile incorporating 39000ft and 5000ft, could everyone on board have been dead from that point and the profile still have been flown by the automatic flight system?
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Old 5th May 2014, 14:23
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Val

It could be programmed in such a way that it could make a series of climbs or a descents but not both (other than the final descent after the fuel runs out!!)

If the aircraft is flown in VNAV (vertical flight path) and is at say 37000 and a way point altitude of 6000 feet is entered at some point down line then the aircraft will descend to reach 6000 feet point in flight idle descent PROVIDED that 6000 has been entered in to the MCP altitude window, the reverse (climb) is true, but unless some one makes a further amendment to the MCP target it won't climb or descend again.

If you were at 37000 feet and selected 43000 at some point down line (even if this was above the aircrafts CRZ capability at that mass) and entered that in the MCP window, then the aircraft would attempt to make that climb, the speed would slowly decline until just above the min speed and VNAV would likely revert to level change with near zero rate of climb, it shouldn't stall, VNAV would not re engage without human input.

In other words it will not leave any FL or altitude in VNAV unless the MCP window is set to a different value, if the FMC constraint was FL100 and you selected 100ft in the MCP it would only descend to FL100, not 100 feet.

You could program multiple climbs or descents, but not both, so starting at 370 you could set WP 1 to 350, WP2 to 300, WP 3 to 270 and so on, BUT the MCP would have to equal the lowest programmed value for it to achieve that, ditto the reverse in the climb, so stepped climbs or descents are of course possible (creating the illusion that someone is in control?) but not up and down without someone in control !!

This flight went where (ever?) it did because someone made it so, not a Li on battery fire or cockpit 02 fire.

The and only saving grace in this event (from an industry point of view) is that it wasn't a dream liner, that could well have resulted in a fleet wide grounding, even if not justified by the facts, but after the previous battery problems one could understand why

Last edited by LNIDA; 5th May 2014 at 14:47. Reason: after thought
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Old 5th May 2014, 14:40
  #10459 (permalink)  
 
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Question Pingology

Did you also account for the satellite motion due to orbit inclination?
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Old 5th May 2014, 15:29
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Good post LNIDA, that should clarify the nav system operation.

The important point bought out is that there are only two possible scenarios. At the southerly turn point there was either a live operator at the controls to manually select a southerly heading with the heading select control or the FMS had been preprogrammed to make the turn and a live operator was not required.

Either option suggests that the person in control of the aircraft had some training on nav. system operation but it does not imply that a crew member was flying the aircraft. The system is simple enough to operate that a lightly trained hijacker could have steered the aircraft - after all hijackers took flying lessons for 9/11.
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