Malaysia Airlines Flight Goes Missing En Route to China - Flight MH370

[TNHunter]

I forgot to mention.. It is more like a 'Technology' implemented thru a specification and newly designed avionics Devices.

For a good read on the implementation in the US read this:

http://www.faa.gov/nextgen/implement...programs/adsb/

[Exadios]

Yes it can be changed,

ICAO 24-bit address

Mode S equipment on aircraft are assigned a unique ICAO 24-bit address or (informally) Mode-S "hex code" upon national registration and this address becomes a part of the aircraft's Certificate of Registration. Normally, the address is never changed, however, the transponders are reprogrammable and, occasionally, are moved from one aircraft to another (presumably for operational or cost purposes), either by maintenance or by changing the appropriate entry in the aircraft's

Flight management system http://en.wikipedia.org/wiki/Flight_management_system

Yes. But none of this is done in flight, in situ or by the pilots. It needs removal and hookup to external maintenance equipment to change the ICAO code.

[Exadios]

Same here. Nothing on US TV, and no sign of it on the BBC news web site.

Australia, the US and New Zealand are searching to the south and west of Australia - at about S42 degrees. There have been a number articles in the NYT, WP, Huff Post detailing this. According to an NTSB source this the highest probability search area.

[xlynx]

This explanation given by Tim Farrar is easy to understand. It seems that ACARS is a reporting software utility. It probably went offline at the same time as the ADS-B for whatever reason. But the actual transmitter device was still functioning and responding to the Inmarsat hourly pings for a considerable time.

http://www.themalaysianinsider.com/s...ngs-tim-farrar

Thanks! quite a good sight there for common technical questions relating to MH370.

[Speed Daemon]

I think the confusion is arising because the "ping" used in the context of the missing MH flight is being confused by the UNIX/Windows/DOS Networking ping command (ie, ping 192.168.1.1).

No confusion at all; Inmarsat is known to use the Internet Protocol a/k/a "TCP/IP". The single largest service that Inmarsat provides is the Internet.

Is it possible that there's another, unknown, network layer protocol being used by Inmarsat? Is it possible that some unknown entity called a "satellite ping" exists at Inmarsat? Well, anything is possible. But when it comes to credulity, the known quantities always trump the theoretical unknown secrets. Those who turn the unknown into sort-of gods aren't collecting empirical evidence.

Here is what we know directly from Inmarsat:

Inmarsat statement on Malaysia Airlines flight MH370

14 March 2014: Inmarsat has issued the following statement regarding Malaysia Airlines flight MH370.

Routine, automated signals were registered on the Inmarsat network from Malaysia Airlines flight MH370 during its flight from Kuala Lumpur.

This information was provided to our partner SITA, which in turn has shared it with Malaysia Airlines.

For further information, please contact Malaysia Airlines.

SITA

From the analysis of the time between request and responce it is possible to work out the distance of the plane which is a circumference of certain radius from the satellite based on which, two possible routes were drawn by the investigators."

It's obviously two circle segments, right on the 40 degree circle, as supplied by the Malaysian government. Based on their previous editing of the facts, I'm going to presume that the Malaysian government wrote the red parts as misdirection; the entire circle is the real plot. If we overlay the flight range map (which I'd like to do, but alas I'm not a graphic artist) we can find a single arc that terminates well inside China at the north, and continues south into Laos, Cambodia and Indonesia, and on into the southern Indian Ocean. That's the centerline.

Another vital question is just how thick that line actually is. How likely is it that it's really as precise as exactly 40.00 degrees declination? I would posit that Inmarsat probably told the Malaysian authorities something like "it's 40 degrees, with only one significant digit." And if that's the case, then the "line would extend out to the 30 and 50 degree lines to match the level of imprecision. That adds Burma to the list, and also puts western Australia almost into reach.

If you can provide the mathematical formulae that demonstrates the level of precision possible from a quartz crystal oscillator? Make a believer out of me!

[smay69]

Yes. But none of this is done in flight, in situ or by the pilots. It needs removal and hookup to external maintenance equipment to change the ICAO code.

OK, I understand now - so the ICAO 24 bit address is tied to the registration. The actual call sign for an individual flight though is set by the pilots, correct? Is it possible to change the call sign (like MAS370) _in-flight_? Let's say they switched off the transponder, flew into an area with no radar, turned the transponder back on, changed the call sign and emerged into radar coverage on a standard flight track - would that set off any red flags automatically with ATC or would someone have to notice the call sign is wrong for the registration for a particular flight plan. Could one file 2 flight plans for the same registration with different call signs or would some system automatically reject that?

[MIT EE]

Australia, the US and New Zealand are searching to the south and west of Australia - at about S42 degrees. There have been a number articles in the NYT, WP, Huff Post detailing this. According to an NTSB source this the highest probability search area.

Last transmitted position was approx. N7 degrees. S42 would be approx. (7+42)*69= 3381 miles from last known position. The folks at INMARSAT are highly competent and am sure we can rely on the arcs that they have put out. So, ANZUS would seem to be looking in the right place. The US is using the Boeing P8, the only other country flying that is India. It was initially used by the Indians when they were participating in the search. Perhaps, they could make it available again to the Malaysians, if they asked nicely.

http://en.wikipedia.org/wiki/Boeing_P-8_Poseidon

[Exadios]

Thanks! that answers #2. It's fully plausible the radar transponder, ADS-B and ACARS equipment all offlined at 1:21.




Thanks! That's the answer to my question #4 then.



Now, my only real remaining question is #1, reworded:

Is there any evidence ACARS was switched off and did not fail? Was MH370's ACARS equipment built to send a disconnect signal to indicate a graceful shutdown?

This seems a crucial question, because the original suspicions were based on a faulty assumption about ACARS offline time and the likely incorrect belief this occurred before the last comms and transponder offline. There's still the reprogrammed flight computer, but is that a strong enough case to focus on possible hijacking rather than equipment failure?

MAS has already stated that they do not, and cannot, know when the ACARS failed / was disabled. The last good message was received at 01:07. The next message, due at 01:37, was not received. MAS has contradicted the Malaysian administration on this matter which claimed that the ACARS was turned off at 01:07.

One of the things to understand is that Malaysia is basically a one party state and ruled mainly by party prince lings. They are really only competent at using British colonial era laws to oppress any opposition and keep themselves in power. In most other areas they are not very competent. It shows, doesn't it.

[MIT EE]

It's obviously two circle segments, right on the 40 degree circle, as supplied by the Malaysian government. Based on their previous editing of the facts, I'm going to presume that the Malaysian government wrote the red parts as misdirection; the entire circle is the real plot. If we overlay the flight range map (which I'd like to do, but alas I'm not a graphic artist) we can find a single arc that terminates well inside China at the north, and continues south into Laos, Cambodia and Indonesia, and on into the southern Indian Ocean. That's the centerline.

Another vital question is just how thick that line actually is. How likely is it that it's really as precise as exactly 40.00 degrees declination? I would posit that Inmarsat probably told the Malaysian authorities something like "it's 40 degrees, with only one significant digit." And if that's the case, then the "line would extend out to the 30 and 50 degree lines to match the level of imprecision. That adds Burma to the list, and also puts western Australia almost into reach.

If you can provide the mathematical formulae that demonstrates the level of precision possible from a quartz crystal oscillator? Make a believer out of me!

Agreed! The Malaysians are completely unreliable. Wish INMARSAT would realize the info directly.

[Oblivian]

Regarding ping vs ping vs ping.

They shouldn't have adopted the term. But that's the media for you. They have likely done so in the fact that no-one would understand 'heartbeat' or 'keepalive' transmission. The term is likely taken to attempt to portray this, and combined with what most people can relate to - Sonar. Where the transmission sent out and received on reflection is called... a ping

So, if most hear ping.. its the more common term the brain then associates to 'something was sent out or replied to from proving its existence'

[Exadios]

OK, I understand now - so the ICAO 24 bit address is tied to the registration. The actual call sign for an individual flight though is set by the pilots, correct? Is it possible to change the call sign (like MAS370) _in-flight_? Let's say they switched off the transponder, flew into an area with no radar, turned the transponder back on, changed the call sign and emerged into radar coverage on a standard flight track - would that set off any red flags automatically with ATC or would someone have to notice the call sign is wrong for the registration for a particular flight plan. Could one file 2 flight plans for the same registration with different call signs or would some system automatically reject that?

The ICAO code is tied to the air frame. The registration may changed from time to time. For instance, United sells one of its craft to MAS. The plane would lose its US registration and gain a Malaysian one. However, the ICAO code remains the same.

The crew can change the call sign / flight number. This may cause some confusion in real time. But on play back the reference is definitely the ICAO code and the switch would be obvious.

[smay69]

The ICAO code is tied to the air frame. The registration may changed from time to time. For instance, United sells one of its craft to MAS. The plane would lose its US registration and gain a Malaysian one. However, the ICAO code remains the same.

The crew can change the call sign / flight number. This may cause some confusion in real time. But on play back the reference is definitely the ICAO code and the switch would be obvious.

I realised I could test this by just playing back that night, filtering by registration (on this site the registration field quotes the ID but also a 24 bit address, so I assume the ADS-B info includes the 24 bit address and this site has a mapping to the registration ID) and watching to see if it re-emerged anywhere after it disappeared based on the 24 bit address. It didn't. There were rumblings of Squawk code swapping, but the 24 bit address wouldn't change. Does this site get the ICAO addressees based on the ADS-B data directly, or is that somehow looked up based on Squawk code? I can't imagine the Squawk could actually be trusted for anything.

[Speed Daemon]

Speed Daemon is correct. It would take a technician with the avionics on the bench to change the ICAO address. The ICAO code is like a VIN code assigned to a car. It is supposed to be assigned to a airframe. The issue with ABS-B is it requires receivers and they have an effective line of sight range of about 250nm (when the aircraft is at higher altitudes). At this time there are no space based ADS-B receivers. Also, ADS-B is being set to a world wide standard but has not yet been implemented world wide. NORMALLY if the 1090 Mose S transponder is turned off the 1090 ADS-B (Mode ES) stops being transmitted. If there is a 1090 ATCRBS or Mode S being transmitted (no 1090 ADS-B) there could be a UAT ADS-B broadcast that is separate. Some avionics packages are linked (ADS-B data packet Mode S 4096 code is matched) and some that are not linked. The Garmin GDL-88 has a mini interrogator that sniffs the 1090 4096 beacon and matches it if received or sets its 4096 beacon code in the UAT data packet to 1200 if no 1090 code is detected. We have to work around that issue at times.

Thanks for all of the additional info!

I think that some who are less familiar with large commercial airframes tend to not look beyond what they see in the cockpit. The real work is being done in the avionics bay, and the cockpit panels are just the "face" of the systems that are running in nondescript boxes, or cards in card cages. Most commercial airliners have extra "hard points" and card slots to accommodate future expansion, or spare equipment. That means that an airline mechanic could conceivably bring a second one of whatever has the ICAO code in it, fitted with a counterfeit code, and leave it for the hijacker to swap in during the flight. If that is a card, it might not take any tools at all! That would make this a "conspiracy", of course...

[Oblivian]

https://www.youtube.com/watch?v=XnfXwyh-8KY

Upon analyzing this video and logging the altitude, speed and Vertcal Velocity at a minute interval. It seems the distance traveled does not match the distance calculated using displayed aircraft speed.

Flight leaves at 16:41 and reaches cruising speed of 480 knots at 17:03. Crosses K.Terennganu into S.C.Sea at 17:11.

The distance from KL-KT is about 210 miles. The distance calculated using FlightRadar speed is about 165 miles.
Any body know why there is such a difference ( 210 vs 165).

Distance = .5*(time to get to cruising speed) *cruising speed + cruising speed * time at cruising speed. 1.15 miles = 1 nmi.

If the times are right, then the speed has to be almost 600 knots for it to cover 200 miles in about 30 mins. Is there something amiss here or is there a tail wind of 120 knots at this altiitude??

You are comparing GROUND speed, with transmitted AIR speed. They do not cover the same distance in reality.

[mckinley]

If this question has been asked and answered, I apologize - I did try to do a search and keep up with the thread.

After seeing this quote, "Flightradar24 co-founder Mikael Robertsson . . . said it was also unlikely that MH370 had crashed on land because its emergency beacon would have automatically broadcast the location via satellite or radio." I became curious about those beacons and did some quick searches.

What I found were sites that said that a plane flying over water must carry two types of radio beacon: (1) an ELT which will deploy and activate upon G-forces consistent with a crash (I assume that this is the beacon referenced in the quote); and (2) an EPIRB that will deploy and activate automatically upon contact with water. Both of these beacons send out a signal that is picked up by a satellite network that covers the Earth below about 70 degrees latitude (Wikipedia). They contain a GPS device that transmits its coordinates to the satellite, which reports the information to Mission Control Centers and Rescue Coordination Centers which the initiate SAR. I have seen reports saying that no EPIRB signal activated from MH370.

Does anyone have knowledge of these beacons? Specifically, I am wondering:
* Can they be disabled by the pilot or another person onboard the airplane?
* Are they reliable? Have there been cases where they failed to deploy or activate after a crash into water?