How do they know this? How can they know this? Unless they’re going off the Malaysian military radar. the transponder was switched off, so we have no idea if it blew up a minute later, or flew for hours.
If the plane did fly on for hours (and again, I don’t know how they could know this, since WSJ requires subscription), then the debris on the satellite image is a wild goose chase.
I googled “Engine Data, Malaysia Flight” and saw lots of breaking news about the airline receiving data from the engines. There were a few stories that mentioned the 4 to 5 hours flying after vanishing in some of the sumaries but the ones I saw quoted the WSJ.
Here's a couple of links that help clear up some points.
Looks like the plane and passengers could be abducted to a remote airfield anywhere inside a huge compass circle.
There's probably a pile of cryptic money behind what appears to be a very sophisticated operation.
"U.S. investigators suspect that Malaysia Airlines Flight 370 stayed in the air for about four hours past the time it reached its last confirmed location, according to two people familiar with the details, raising the possibility that the plane could have flown on for hundreds of additional miles under conditions that remain murky.
Aviation investigators and national security officials believe the plane flew for a total of five hours based on data automatically downloaded and sent to the ground from the BoeingCo. 777's engines as part of a routine maintenance and monitoring program."
http://online.wsj.com/news/article_email/SB10001424052702304914904579434653903086282-lMyQjAxMTA0MDEwMzExNDMyWj
"ACARS (Aircraft Communications Addressing and Reporting System) is a radioteletype mode developed in the early eighties as an addressable, digital data link for commercial and business aircraft. Aircraft performance info is sent via ACARS uses the AM mode because the same airborne VHF radio is often also used for voice communications. Burst transmissions are used with a limit of 220 characters per message. Transmissions often last less than one second!"
http://www.universal-radio.com/catalog/decoders/acars.html
The article explains the engines routinely send performance data to roll Royce as part of a maintence contract with Malaysia airlines.
” the transponder was switched off”
That doesn’t mean the RADAR did not see the airplane.