The news media and news reports do not understand the data down link on the 777. There are 2 separate systems. ACARS and AHM System. The ACARS downloads an engine data report three times during every flight: at gear up, at cruise initiation (1:07 am), and gear down. The system was not disabled. The gear never came down so the final data report was never sent. The second data reporting system is called Airplane Health Management system. It is built into every 777. It is always operating. The system reports to Boeing servers thru Iridium low earth orbit satellites once per hour. The airline must pay a subscription fee to obtain the data. MAL was not a subscriber. They did not get any data; however, they system pings the server once per hour over the life of the aircraft. The ping would travel thru the nearest Iridium satellite to the Boeing server. The server would log the time and aircraft ID. By back - tracking thru the satellite system that handled the pings would allow the ground folks to reconstruct the flight path. That is why India has been asked to help and why the destroyer Kidd has been sent to the Indian ocean.
Thank you for the information.
Thanks. Great info
Thank you.
Since MAL was not a subscriber, this is probably a reporting system that even the pilots were not aware of. Whether the hijackers were the two MAL pilots or were passengers, when the hijackers turned off the transponders they probably had no idea about this other system pinging satellites periodically. So this satellited pinging mechanism was probably not turned off by the hijackers. Indeed, if they were aware of it and how to turn it off (if that is even possible), then they would have done so hours earlier when they turned the transponder off.
If that is the case, the plane crashed or landed somewhere in the flight radius between where the last ping occurred and when the next ping would have occurred.
How do you know the ACARS was not disabled?
What is ACARS using to report status? Is it using SATCOM? If so, couldn’t it be disabled by a hostile crew? It’s farfetched but possible. As for AHM, are you saying it pings the Boeing servers even if the country isn’t a subscriber? Nevertheless, an Iridium transceiver could be disabled, too. Again, it would take a knowledgeable crew to do something like that, but I think that’s where the conspiracy theories are leading. If a terrorist crew was smart enough to take over the flight and fly it to a secret destination, they’d probably know about the on board systems.
The reporting has been all over the map on this. Can you confirm/refute stories that state the AHM can:
- Send altitude data
- Send Direction of travel data
- Send positional data
Thanks
Well stated and then there’s the satellite fleet of the USAF. They have over 900 of them many of which can look down. We watch these waters as closely as anyplace and I’m not believing that somewhere in the recorded data is at least a blinking light path that came from this plane——also confirming to me why the Kidd is going where it’s going. Note also that, apparently it’s the Kidd and only the Kidd, even tho Task Force 150 is near by as well as the rest of 5th and 7th fleet operations. The lack of “wheels down” data is a bit spooky meaning the plan just didn’t work out.
Thank you for the succinct explanation. It has been driving me crazy, reading the various articles that just chum the waters with their inadequate explanations and unsourced quote mining for maximum effect.
Journalism is killing itself with unprofessional and incompetent writing.
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I still stand by my analysis in post #8. Based on what has happened in the last 24 hours let explain what is actually happening. There are now “2” tracks that they are looking at. One going to the northwest and the second to the southwest. Why 2 tracks? Because they are looking at ranging data “from the aircraft to one geostationary satellite (22000 miles), that happened to picked up the pings; 2 geo satellites would be required to eliminate one of the tracks”. Now, the AHM system is designed to work with the low earth orbit Iridium satellite system. The Iridium system provides global coverage. Why aren’t they analyzing the Iridium data? I do not know. That data should give a very accurate ground track of the plane.
How do you know it was not subsequently disabled after 1:07? It would provide a significant data point as to where the flight landed. And an experienced pilot would know that.