Flightradar24.com
Here is a #MH370 situation update from Flightradar24 because of the many questions we get.
The ADS-B transponder of an aircraft is transmitting data twice per second. FR24 saves data every 10-60 second depending on altitude. On cruising altitude data is normally saved once per 60 seconds. By analyzing all our databases and logs we have managed to recover about 2 signals per minute for the last 10 minutes.
The last location tracked by Flightradar24 is
Time UTC: 17:21:03
Lat: 6.97
Lon: 103.63
Alt: 35000
Speed: 471 knots
Heading: 40
Between 17:19 and 17:20 the aircraft was changing heading from 25 to 40 degrees, which is probably completely according to flight plan as MH370 on both 4 March and 8 March did the same at the same position. Last 2 signals are both showing that the aircraft is heading in direction 40 degrees.
Today there are reports in media that MH370 may have turned around. FR24 have not tracked this. This could have happened if the aircraft suddenly lost altitude as FR24 coverage in that area is limited to about 30000 feet.
FR24 have not tracked any emergency squawk alerts for flight MH370 before we lost coverage of the aircraft. Playback for flight MH370 is available on Flights database - Flightradar24
Well that's useful clarification, thank you.
Is it fair to conclude from the above then, that if your coverage was still functioning, that the aircraft descended from FL350 to below FL300 sufficiently quickly (less than 30 seconds) that there was no time for a further reading to be taken.
The only other possible explanation is that the transponder stopped functioning. Or was switched off.