WSJ reports that the aircraft flew for at least 5 hours.
- Based on automatic engine data sent via ACARS to Rolls Royce, "U.S. investigators" believe the aircraft flew for hours beyond the last confirmed radar contact location. (Wall Street Journal )
- Approximately 5 hours total flight time / would be about 2,200nm range
- Engine reports sent every 30 minutes via ACARS
- ACARS messages can be sent via VHF to ground stations or SATCOM. VHF would require line of sight to a ground station.
- Some ACARS message sets include position information in every downlink message- it has not been made clear if this was the case for this aircraft
- U.S. "aviation investigators" & "national security officials" possibly involved - mentioned in article
- "U.S. counterterrorism officials are pursuing the possibility that a pilot or someone else on board the plane may have diverted it toward an undisclosed location after intentionally turning off the jetliner's transponders to avoid radar detection, according to one person tracking the probe."
- "At one briefing, according to this person, officials were told investigators are actively pursuing the notion that the plane was diverted "with the intention of using it later for another purpose.""
- More detailed info regarding the RollsRoyce monitoring system .
The engines' onboard monitoring system is provided by their manufacturer, Rolls-Royce, and it periodically sends bursts of data about engine health, operations and aircraft movements to facilities on the ground. Rolls-Royce couldn't immediately be reached for comment. As part of its maintenance agreements, Malaysia Airlines transmits its engine data live to Rolls-Royce for analysis. The system compiles data from inside the 777's two Trent 800 engines and transmits snapshots of performance, as well as the altitude and speed of the jet. Those snippets are compiled and transmitted in 30-minute increments, said one person familiar with the system. According to Rolls-Royce's website, the data is processed automatically "so that subtle changes in condition from one flight to another can be detected." The engine data is being analyzed to help determine the flight path of the plane after the transponders stopped working. The jet was originally headed for China, and its last verified position was half way across the Gulf of Thailand. A total flight time of five hours after departing Kuala Lumpur means the Boeing 777 could have continued for an additional distance of about 2,200 nautical miles, reaching points as far as the Indian Ocean, the border of Pakistan or even the Arabian Sea, based on the jet's cruising speed.