The Dutch Safety Board preliminary report stated that both the Cockpit Voice Recorder and Flight Data Recorder stopped recording at 13:20:03 UTC time. That is 16:20:03 local Ukrainian time.
However, according to the clock shown on the Rostov Air Traffic Control radar, after the CVR and FDR stopped MH17 continued to fly at Flightlevel 330 and a speed of about 900 km /hour for 44 seconds before the speed and altitude dropped rapidly.
Another remarkable fact is that the speed and altitude are still shown at all. Especially the altitude as a transponder is required to read the altitude of an aircraft on a radarscreen. This means that at the same time both CVR and FDR were not recording anymore, the transponder of MH17 was operational. The antennas for transmitting transponder data to the radar are located near the cockpit. One antenna on the belly and one on top of the fuselage. If the cockpit was separated there would be no antenna to transmit transponder data.
CVR and FDR are located in the back of the aircraft. There must have been an enormous force which caused the recording to stop.
avherald.com is a well informed very reliable site on aviation incidents. On MH17 it says “transponder data became unreliable at 13:18Z (position N48.28 E38.08)”. There is no source provided. So how Avherald.com knows the transponder became unreliable is not known.
So lets us have a look at the transponder data. Flightaware.com does not have coverage over Ukraine. Flightradar24 does have coverage.
See this Tweet of Flightradar 24. It shows the transponder data received by Flightradar24 shown in the table below. The last two most recent reports show a position which is beyond the crash site. How is that possible? Flightradar24 sent out a Tweet stating those two reports are real data and not extrapolated.
On radarspotting is an interesting thread on how reliable the last two reports of Flightradar24 are. This site is about an aircraft tracking site called Plane Plotter. The admin reports their data is accurate up to the second.
Flighttrackers use the ADS/B signal transmitted by aircraft equipped with a transponder. The transponder transmits each second position, speed, altitide and an unique ID on a radio frequency . Data can be intercepted by anyone equipped with a radio. The radio can be a very cheap device. ADS/B is not encrypted.
Flightradar , Planefinder and other trackers make use of volunteers. These have a radio, an internet connection and software to translate the radio signals into data. They feed the trackers with their data. The trackers do not collect each second of data. It depends on the tracker but could be like each 2o seconds.
Sputniknews reported on July 25 that aircraft flying over Ukraine reported problems with GPS. It is also known that aircraft overflying Germany and Austria disappeared from radar in June. Severall German and Austrian newspapers reported about this.
It is also know ADS/B can be spoofed. See this article for example in Forbes.com titled Next-Gen Air Traffic Control Vulnerable To Hackers Spoofing Planes Out Of Thin Air
The table below shows a collection rate of just over 60 seconds.
And this video shows a closeup of the same radar screen.
Assumed is that a missile exploded close to the cockpit. This resulted in the cockpit and business class section were separated of the rest of the aircraft. Because the feed of both the cockpit voice recorder and flight data recorder is sent from the Airplane Information Management System (AIMS) located near the cockpit, this could be the reason both CVR and FDR stopped recieving data.
It this has happened it is strange the fuselage now without cockpit continued to fly at the same altitude and speed. You would expect that because of much degraded aerodynamics and cut of of all controls the aircraft would immediately respond.
The table below shows the data as seen on the Rostov Radar image. It is almost exactly the same data as shown by Flightradar24. Mind there is a big difference in speed. I believe this is Indicated Air Speed and Groudspeed (Flightradar24)
The first colomn show the time on the radar screen. This is the local time in Rostov.
The second colomn shows the number of minutes and seconds into the video
The third colomn shows the altitude of MH17 reported by the transponder (SSR = secondary survaillance radar)
The fourth colomn shows the speed of MH17 in km/h reported by the transponder (SSR = secondary survaillance radar)
The fifth colomsn shows the direction of MH17 in degrees from waypoint TAMAK. This is located the Ukraine/Russia border (primary radar, no transponder)
The seventh colomn shows the distance in kilometers to waypoint TAMAK.
I cannot find other reasons to explain this other than:
- the computer at the Rostov ATC does a prediction of the future speed and altitude of MH17 while the aircraft is actually not at the previous altitude and speed. Some latency will also be part of delaying info shown. For example the primary radar antenna at Rostov rotates. This will cause a few seconds delay. However both the secondary AND primary rader are reporting continued speed and altitude after CVR and FDR stopped recording.
The radar antennas for Rostov are located in Apoi Baturin en Ust-Donetsk.
Rostov Radar is using radar system produced by Spanish Indra Sistemas S.A . It will be replaced in the future by a system called Syntese
Some less likely explanations are:
- the Dutch Safety Board mentioned an incorrect time in their report
- the time on the CVR and FDR were incorrectly set
- the time on the Rostov radar screen was incorrect
- the recording of Rostov radar has been manipulated