[robert14]

Hello again Cboldt. I assume that both systems use the same onboard transponder. They each must have their own processor that shares the transponder. The AHM, according to the Boeing ad, contains 160,000 parameters. That has to include GPS data. If not, it surely includes altitude, heading, and airspeed from the air data/pitot system. Did you see the just published photos of the 777 floating in the water off the coast of Malyasia? I am assuming the image is photo shopped.

[Cboldt]

From research so far, AHM is a data conversion and analysis program by Boeing, with the data being provided by an ACMS. Not to say this is the system on the 777, but see Teledyne Controls ACMS description shows operational parameters other than location; and lots fewer than 160,000 parameters.

Wiki on ACARS says, "Most ACARS messages are only 100 to 200 characters in length."

If this flight had been transmitting GPS data, the search effort would be substantially narrowed.

I did see the photos that are claimed to maybe be this flight, in shallow waters off the coast of Malaysia. Most unconfirmed reports end up being no more than gum-flapping. Keeps people reading the news and catching the advertisements.