Okay, that makes sense.
Where the news program was misleading was that it implied that the plane flew faster the entire time. Obviously, it couldn’t have, or it would have ended up farther south than the original search area, not farther north. (But I only watched the first minute; maybe they cleared it up later in the report?)
Yep —
According to the Malaysian military thus far, after taking 2 minutes to turn around, the plane went up to 45,000ft and flew at the new western heading for 23 minutes — but how fast they didn’t say. Apparently they are saying now and it was faster than thought.
Then after those 23 minutes it dropped down to 12,000ft and as low as 5,000 — but how fast it was flying and for how long at that altitude Malaysia would not say. Apparently they are saying now and it was faster and longer than thought.
If it then flew faster at 12,000ft it would have not only used up more fuel but also have gone further toward waypoint IGREX than their 450 model was assuming.
Note that on that graph the 400 red line south begins up further northwest than the 450. The 450 yellow line also shows a flight path over Indonesia which I don’t think this pilot would risk.
The faster it went for the first 2, hours, the slower it had to go for the last 5 hours to hit those Inmarsat pings rings.
Hence the 400 knot route and the new search area. They should have been in that area 3 weeks ago.