- ACARS is an automated aircraft health management system that transmits a/c maintenance information. ACARS is NOT a flight system - it is not needed for safe flight - it is a maintenance system
- SATCOM Pings sends (or responds to) periodic 'pings' to/from the satellites. These 'pings' are a network communication that says "I am here." They are often called "keep alive" signals.
- 12:41am from Kuala Lumpur International Airport flight 370 takes off with 239 people. Enough fuel to fly for eight hours.
- 01:21am Transponder disabled (near waypoint IGARI)
- 1:30am The last comms were a normal hand-off from Malaysia to Vietnam control
- 1:30am Normal 'good night' on the Malaysian side, but Vietnam was not contacted.
- 08:11am Last ACARS routine handshake signal detected through the Inmarsat satellite network.
You'd have to possibly pull circuit breakers if you wanted to deactivate all communications equipment, systems include transponders that inform air traffic controllers of plane's position, as well as cockpit radios and ACARS, a text-based system that's used to send data to and from planes.
Remember it's 1:30am, most passengers are asleep, it's pitch black outside, most mobile phones are turned off, (to save batteries mostly)
1:21am Senior pilot says goodnight to Malaysia control.
Senior Pilot disables Junior Pilot (or visa versa) and the proceeds to shutdown all communications.
Incapacitates remaining crew and passengers by going to an unsafe altitude of around 40,000 feet and turning off the air and oxygen Mount Everest is 28,000 feet and there's only 7% oxygen.
The passenger oxygen masks will drop but have only 10 minutes supply of air. Flight cabin crew have 2 hours of air.
After 10 minutes passengers will all start to succumb to Hypoxia (light-headedness, fatigue, numbness and then coma)
30 to 45 minutes later Pilot turns back on air and oxygen. And continues flying another 6 hours
8:11am last signal, plane almost completely out of full at that point, probably ditched in ocean or if more people where involved from the ground potentially landed remotely (unlikely)
The main question would then be why...