My understanding is that the ACARS can be switched off in the cockpit. But to totally disable it, someone needs to go into the avionics bay. The ACARS in MH370 was only switched off in the cockpit. The fact it wasn't entirely disabled is why Inmarsat was able to pick up the hourly "handshakes". The transponder tells the planes identity, location, altitude and speed. It doesn't have flight information programmed into it - that's the flight management system.
Feel free to correct me though. I've only come to learn any of this these last few weeks.
Actualy it doesnt Tell exact location, only longitudinal information, which is why for several days last week the news media was showing maps indicating two possible flight paths (one north, one south) at the end of the initial westerly, off track diversion. They got those projections from the US intelligence folks, who finally kicked into gear after it became obvious that Malaysia was in over its head in an investigation of this complexity.
Neither does it tell speed or altitude. Just a rudimentary ID: I am here. The int folks ruled out the northern possibility fairly early on. The nations along that route would not have neglected to respond to a real time, unidentified target encroaching on their airspace, as the Malaysians did. Despite the fact that the Malaysians went out of their way to pat themseles on the back as to their response to the disappearance, their response was inept and slow.
the transponder is capable of providing much more information, even in its off mode as in this case, but that service cost the airline more money, so it only told the satellite the most basic info: I am here.
Here, in this case, is a vast area, many hundreds of square miles greater than the search area for Air France 447. In that case, its last known position was known immediately, the sea floor was mapped (unlike the southern Indian Ocean), wreckage was discovered in good time (unlike MH 370, which took almost two weeks) and, still, it took TWO years to find the hull and the "black boxes."
Some suggestions: be very skeptical of everything in the media (particularly the ny times and cnn, although they are not the only ones trying to make a buck off this mystery), and don't expect a timely resolution. They may stumble on the wreckage tomorrow, if lucky. If not, expect years, even decades, of doubt.
I am wondering how long CNN is going to devote most of its time to this mystery. 176 missing and presumed dead in Washington State? Why? CNN is still too content with its ratings to care about the missing in Washington, but eventually the viewers are going to realize there really is very little "breaking news" in the distressing mystery of MH 370.
