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Old 19th Mar 2014, 01:36   #5881 (permalink)
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Originally Posted by papershuffler View Post

The Malaysians may be thinking, 'You're going to blame either our pilots, procedures, or maintenance instead of your US-made aircraft, why should we work with you?'
And all that blame may well be completely unfair, but the Malaysians WILL be fairly blamed for their initial in-flight emergency response.
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Old 19th Mar 2014, 01:38   #5882 (permalink)
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Deriving the course from the Inmarsat pings

Originally Posted by Heli-phile
So what heading/ speed did you use and was was the results?
What I have done is a demonstration that the course can be derived, if the interim pings are available. Without the actual ping data no further progress is possible.
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Old 19th Mar 2014, 01:39   #5883 (permalink)
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"Be transparent" could mean anything up to "we know exactly what happened to the airplane and we know that you know. And we are giving you a chance to announce it first." Just saying.
Yep, but with the amount of verbal 'misunderstandings' there have been so far, are you sure they'll understand what the US are saying?

That is a valid position to take, as it is their airline, and the flight originated in their capital. A number of nations will doubtless be happy to assist. The UK and US are obliged to since Engines and Aircraft were built in those two nations.

Therefore, UK and US will be none too interested in a cover up. What they'll want is an actual investigation. My experience with morals and ethics in the third world advises me that this requires some effort to elicit, and pressure at time not to fall into the same old same old corruption that a certain airline captain was vocally against.
Very much an understatement; IME, I would have said nigh-on impossible. Records are 'lost' and witnesses disappear. Legal proceedings take years. Letters go amiss. No one returns your calls. People virtually laugh in your face. Sometimes it doesn't even take a third world country for this to happen.
Without considerable international pressure, I don't have faith in important evidence (e.g. maintenance records) making it to the investigative team, whoever and wherever they may be.

We've seen it all before; as time goes by, the shock will abate and career- and face-saving will take precedence, if it hasn't already.

It will be interesting when/if the fate of MH370 is finally discovered, how much involvement the Malaysians wish to take in the proceedings.

(Personal opinion/suspicion: if it hadn't been (more-or-less) confirmed that the FO Fariq Abdul Hamid was the last voice heard and therefore still alive, I suspect the negative stories discrediting Capt Zaharie would have gathered more pace...)

Last edited by papershuffler; 19th Mar 2014 at 04:58. Reason: extra word deleted/moved to make sense
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Old 19th Mar 2014, 01:40   #5884 (permalink)
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Thanks for more confirmation of the WP being changed pre-ACARS report. Think I will still leave it as "apparently" though, as some data seems to be "confirmed" then debunked later when Malaysia decides to actually share the data instead of whatever they decided their theory of it was at whatever moment.

As far as your note - any system failure would have sent out an emergency ACARS. If the Transponder did drop because of a catastrophic event it would have. If merely turned off, I am not 100% sure. (but I think it would have) Hopefully someone else can clarify that last bit
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Old 19th Mar 2014, 01:56   #5885 (permalink)
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Originally Posted by GarageYears
I keep seeing questions related to why the SATCOM system was sent pings, etc, and discussion related to ACARS use, MAS subscription to the ACARS reporting service to Boeing (or not), but isn't it also the case that the SATCOM transceivers at ALSO available for voice comms?

Yes, 777 cockpit SAT comms out of the tin, and optionally, in-seat passenger satellite linked phone service.
Ah, thanks for the confirmation.

Right, so that puts to bed the occasional "well-if-they-aren't subscribed to Boeing's data monitoring... why does the satellite ping them" comment I've seen. The pings are there just as much for the cockpit voice comms link, as any data that may or may not be sent over the same link.
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Old 19th Mar 2014, 01:57   #5886 (permalink)
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Deriving the course from the Inmarsat pings

So what you have done is say you cannot join the dots if there is only 1 dot..... OK

Last edited by Heli-phile; 19th Mar 2014 at 01:57. Reason: original was too sarcastic!
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Old 19th Mar 2014, 01:58   #5887 (permalink)
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That last PING arc.

There still seems to be confusion over the 40 elevation angle arcs accredited to the last 'ping' timed by the Inmarsat IOR at 64E over the equator.

The graphic below should provide insight into how that elevation relates to any angle subtended from the earths center in any plane. Note the graphic doesn't indicate the top or bottom of the earth sphere is North or South, as it could equally be 154E or 26W. Also, from 35,768km above the equator, the full disc is not seen, as reference to the graphic will show. 90 elevation is on the beam centerline, but at an earth elevation of 50 the angle subtended from the center of the earth is 35 and the angle at the satellite is 5 of its overall half beam-width of 8.7.

When plotted on a transverse Mercator chart/map, the ring drawn will start being circular immediately below the satellite, but as the angle gets bigger the Mercator projection makes the projection elongated in a polar direction. If drawn on a equidistant projection, the circles would remain just that.

Those who have referred to the AMSA search graphics will note that the tracks supplied by the NTSB are based on two different ground speeds, and they reproduce the diverging tracks. The track indicating the faster speed is the westward one.

Last edited by mm43; 19th Mar 2014 at 02:14. Reason: spelling!
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Old 19th Mar 2014, 02:04   #5888 (permalink)
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For me this looks like there has been failure situation / slow decompression or problem with Oxygen for crew, they might have started diversion, altitude change, possible some issue with the Avionics, I don't know the T7 systems, so can't comment on details of this.

At one stage they have BOTH become incapacitated, and descended in altitude, flown on until running out of fuel (Similar Helios)

What exactly caused this to happen, none of us can only speculate in, but what is important is to create the most likely scenario and work with this.

Most such scenarios it will the most simple and least spectacular version that will be the truth.
The problem with this though is it conveniently ignores some parts of the data that just don't fit. Such as the voice radio transmission sector change acknowledgement AFTER the transponder was shutdown, etc.

Unfortunately it doesn't seem what is postulated is the simplest solution to all the information that we know, even if that answer isn't one that we'd like it to be.

Coming up with a half-baked hypothesis (and I'm not trying to insult anyone here) and suggesting the plane flew off in the murky blue yonder for 7 hours or so until it flamed out, doesn't seem to fit with the last radar track point and the INMARSAT ping arc.
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Old 19th Mar 2014, 02:15   #5889 (permalink)

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What are all these photos turning up in the media of jets in the jungle.
jets under the water "showing" wings and windows ?

Have they all been debunked and the media just using them to sell newspapers ?
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Old 19th Mar 2014, 02:18   #5890 (permalink)
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Range can be extended by lowering cruise speed?

The Malaysian government has released an image showing maximum distance aircraft could have travelled - is this based on range at cruise speed or less?

As far as I know, range can be extended by flying at slower than the typical cruise speed listed as 490 kt?

What is the best range speed?

The speed which gives the maximum range for a given aircraft weight and altitude is called best range speed. Flying at higher speeds than the best range speed increases the drag and the fuel flow, and therefore reduces the range. Lower speeds than the best range speed reduce the drag and the fuel flow, but they also reduce the distance traveled per time which is more dominant, and therefore reduce the range.

SKYbrary - AP4ATCO - Factors Affecting Aircraft Performance During Cruise
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Old 19th Mar 2014, 02:26   #5891 (permalink)
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Waypoint programmed but not executed.

For direct access to my "nearest suitable", I have often pre-programmed (but not executed) a "Direct to ABC" and sat there watching a dotted pink line with an accurate track arc peeling out from the nose.

Would that sort of behaviour cause a log event in the ACARS or would you have to "Execute" for it to log?
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Old 19th Mar 2014, 02:27   #5892 (permalink)
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ACARS at 1:07

If a plausible theory says that the 1:07 ACARS is that of the 12 minutes window to change a waypoint to do the westward turn. I wonder if it is likely the other subsequent waypoints of the new path that are keyed in would appear in the ACARS message? Afterall ACARS contains enough capability of interfacing with the FMC on flight path changes - in uplink and downlink modes.
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Old 19th Mar 2014, 02:31   #5893 (permalink)
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Do we actually know, other than third hand unsourced rumours from Reuters or the WSJ :

1. if the thing actually flew through the waypoints then turned to the new tracks, or just flew near them ?

2. when Vietnamese or Malaysian air traffic actually declared a SAR phase and messaged this to neighbouring country's air traffic services organisations ?

3. if Burmese or Bangladesh radar ever painted anything ?

4. if 'goodnight' etc was all that was said (bad) or was just tacked on to the end of a normal frequency change acknowledgement (good) ?

5. where the story about the new wpt in the FMS came from ?

Until we know these for sure, all that we know is that the aircraft is ... missing.
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Old 19th Mar 2014, 02:35   #5894 (permalink)
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Geosynchronous vs. Geostationary

There are 2 operational INMARSAT satellites that were within view of MH370 at various times. A 3rd satellite, INMARSAT-5 F1 was launched in December 2013, but is still undergoing on-orbit tests until mid-July 2014, per Slide 18 of:


Nit-picking a bit, the satellites are geosynchronous, not quite geostationary. Hence their latitude and longitude will vary slightly over the day, typically tracing a figure 8 on the ground. See Figure 3 in this page by T.S. Kelso:

CelesTrak: "Basics of the Geostationary Orbit"

Note that the figure 8 is for a satellite whose orbit has eccentricity of zero, whereas non-zero eccentricity distorts the figure 8 somewhat.

Kelso lists orbital elements in TLE (two line element) format here:


This is the active one for the Indian Ocean Region:

1 23839U 96020A 14077.02691924 .00000003 00000-0 10000-3 0 2792
2 23839 1.6580 73.1420 0005562 281.9751 254.5647 1.00273339 65760

Element 2 in Line 2 is the orbital inclination in degrees, in this case 1.658 deg. Thus both the latitude and longitude will vary a bit over a day, tracing a sort of figure 8

Element 4 in Line 2 is the eccentricity, with an implied decimal point at the left. The eccentricity is 0.0005562 for this satellite.

The N2YO website uses the TLE data to compute present position of the satellite:


The Pacific Ocean Region satellite is INMARSAT-4 F1.

Kelso's TLE data:

1 28628U 05009A 14077.46405487 -.00000269 00000-0 10000-3 0 3195
2 28628 2.6638 355.1900 0002955 355.6954 135.5891 1.00271237 32824

Inclination is 2.6638 deg, eccentricity is 0.0002955.

Tracking data from N2YO:


The latitude will range between plus and minus the inclination angle over one day.

Will attempt to calculate and post the latitude and longitude of both active satellites for the hourly pings.

The search agencies have certainly done this already. Which may be why they have plotted the circle for only the last ping, so they don't get bogged down in explaining to a low tech press pool why the circles aren't concentric.
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Old 19th Mar 2014, 02:35   #5895 (permalink)
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RE: "Better still are you sure it wasn't a UFO he saw and decided to just go on a bit of joy ride, yeah, let's make sure our plan B includes a good swath of Malaysia and just for giggles we'll turn off the transponder. That'll put the meteorite/UFO/bigfoot off for a bit"

Just sayin... there could be a less-than-super-duper-brilliant Plan B in the FMS. That could have the left turn, and be what the investigator leakers are seeing.

Plan B becomes active when executed. An emergency is the reason. Not necessarily UFOs or BigFoot. Maybe from smoke. Or electrical mechanical malfunction. And the comms and transponder fail then as well as ACARS. and off we go (left) on AP.
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Old 19th Mar 2014, 02:37   #5896 (permalink)
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"The problem with this though is it conveniently ignores some parts of the data that just don't fit. Such as the voice radio transmission sector change acknowledgement AFTER the transponder was shutdown, etc."

Some of the problems we are having, is that we have to few facts, and to much fantasy and theories.

How do we know the transponder was shut down before last voice transmission?

Depending on the failure they faced, we do not know what systems that would have failed.
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Old 19th Mar 2014, 02:41   #5897 (permalink)
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Wa wa

The Malaysians have not confirmed a last waypoint as such, but have definitely given the last position that their primary radar tracked the plane to as 320km north west of Penang. You can get that information from the New Straits Times.

Thailand have belatedly corroborated the primary radar data, though they are not giving details.

Last edited by Blake777; 19th Mar 2014 at 02:43. Reason: Insert s in Straits
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Old 19th Mar 2014, 02:42   #5898 (permalink)
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the Maldives are across the red track from starting point. It would have to have doubled back.
Would it have been possible to get from the area of the Maldives where an aircraft was spotted at 0615, to, say, Iran or Pakistan, on the red northern ping arc by 0811 when the last ping was received? Would the aircraft have had enough endurance and speed for the transit?
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Old 19th Mar 2014, 02:44   #5899 (permalink)
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If Thailand had released this information earlier, almost an entire week of search and rescue efforts in the South China Sea could have been avoided. I think this just goes to show how suspicious most of the countries in this area are of each other.
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Old 19th Mar 2014, 02:47   #5900 (permalink)
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In any case, MH370 apparently had a second Flight Plan (Plan B).

And it can be "executed" quickly and easily in an emergency (or by accident?)

Wouldn't it be nice for Malaysian officials to tell us what that Plan B has, waypoints, turns, destinations, and from what source???
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