MH370 ads-b coverage

Aviation
1

Hi,
Can someone from Flightaware please let me know why the MH370 flight was only tracked as far north by FlightAware until latitude 4.7073 (8/3/2014). Note, Flightradar24 was able to track it all the way until it disappeared off secondary radar (Latitude 6.93). That is about 246 kilometres further.

However, a few months prior on 15/11/2013 Flightaware was able to track aircraft much further north to latitude 13.8598. This is approximately over a 1000 kilometres further. Note, this is using actual fixes from ground stations (i.e. the Flightaware system was not just estimating the position fixes).

Many thanks
Mike

2

Wasn’t the transponder turned off or otherwise disabled? Flight Aware cannot track any aircraft that doesn’t have an active transponder.

3

Hi Jon,

Thanks for your feedback. Yes, you are correct that once the aircraft’s transponder is turned off Flight Aware (or any other radar site e.g. Flightradar24) would not be able to track the aircraft.

FlightAware recorded the aircraft’s last position at 1:02 AM Malaysian Local Time on 8/3/2014.
This was at Latitude 4.7073 and Longitude 102.5278.

However, FlightRadar24 was able to track the aircraft all the way until the transponder was turned off. This was at 1:20 AM (Malaysian Local Time) which is 18 minutes later at a position Latitude 6.93 and Longitude 103.59. This is about 269 kilometers further than Flightaware.

However, a few months prior on 15/11/2013 Flightaware was able to track aircraft much further north to latitude 13.8598. This is approximately over a 1000 kilometres further.

Note, this is using actual fixes from ground stations (i.e. the Flightaware system was not just estimating the position fixes).

So it appears Flightaware had sufficient coverage to track MH370 all the way until the aircraft transponder was turned off (and beyond).

So my question is how come the coverage stopped a lot earlier i.e. about 269 kilometers prior FlightRadar24.

If someone could let me know it would be much appreciated.

Thanks
Mike

4

FR24 and FlightAware have independent networks of terrestrial receivers (although there is often overlap) so it’s fairly normal for coverage to be different like this - it’s just a question of “did we have a receiver that was operating and had line of sight to the aircraft at the time”.

1 Like
5

Hi Thanks a lot for your reply. What you say makes total sense. But what I cannot understand is that:

(a) That from approximately February 2013 to Mid November 2013 FlightAware had ground station coverage many kilometres past where the aircraft went off secondary radar near IGARI. Sometimes up to 1000 kilometres past IGARI.

(b) From end of November 2013 to end of March 2016 the coverage suddenly shrunk so the maximum coverage was just to the Northern Malaysian coast line. This about 165 kilometres short of where the aircraft went of Radar. This means a reduction of coverage of over 1000 kilometres for a period of two years and four months.

(c) Around September 2016 it then suddenly shot back to the 2013 coverage. Typically 500 kilometres past where the aircraft went of secondary radar near IGARI.

If you could let me know why the coverage suddenly fell off for such a long time period it would be much appreciated.

Rgds
Mike

6

If you look at https://flightaware.com/adsb/coverage most of our receivers along the north coast of peninsular Malaysia are relatively recent (2018+). In 2014 I expect that there were far fewer receivers; a single receiver going offline probably explains the loss of coverage.

1 Like
7

Thanks for your reply. So I can get my head around all this it would greatly help me if you could fill me in on the following:

(1) In early 2014 was the ground station ‘WMKP/PEN’ either or a combination of:

   (a) A Malaysian government  ADSB ground station
   (b) A Malaysian government  Radar Site (secondary radar)
   (c) A FlightAware owned and controlled  ADSB ground station
   (d) An ADSB receiver run by the public that feeds into the FlightAware network
   (d) Something else if so what

(2) Back on the 15/11/2013 for the flight https://flightaware.com/live/flight/MAS370/history/20131114/1635Z/WMKK/ZBAA if you could please let me know if the ground stations used to track the aircraft between the latitudes 2.8 N until 13.5 N were:

(WMKK/KUL)
(WMKF)
(WMSA/SZB)
(WMKP/PEN)
(WMKC/KBR)
(WPC/UIH)

Also are these ground stations all owned by the Malaysian Government for those that are prefixed by ‘WM’ and by the Vietnamese government by those prefixed by ‘WP’?

8

In general the ICAO codes shown are that of the nearest airport, they don’t show affiliation of the receiver. Tracklog entries shown as “FlightAware ADS-B” are from hobbyist receivers (your case d) or FlightAware-provided FlightFeeder receivers (your case c, mostly), not data from third party ADS-B receiver networks or radar.

Unfortunately we’re getting quite a bit beyond a simple query here and I’d encourage you to look at a custom data report if you need detailed historical info.

9

Thanks for your prompt reply. Just to confirm I understood your last post correctly. Please see below an extract from a historical flight file from early 2014 (KUL-PEK).

FlightAware ADS-B (WMKK/KUL)

FlightAware ADS-B (WMKF)

FlightAware ADS-B (WMSA/SZB)

FlightAware ADS-B (WMKP/PEN)

FlightAware ADS-B (WMKC/KBR)

FlightAware ADS-B (WPC/UIH)

Assuming you website information is correct and that first hobbyist receiver was installed in Malaysia was on 22nd March 2016 (about two years later) then all the above six entries should be FlightAware owned and controlled ADSB ground stations. Is this correct?

10

Those could be either FlightFeeders or hobbyist sites. Given the date, more likely to be hobbyist sites.

11

Thanks for your reply.

You stated “Those could be either FlightFeeders or hobbyist sites. Given the date, more likely to be hobbyist sites.”

According to your (ADSB/Statistics and then selecting Malaysia) the first hobbyist site installed in Malaysia was on the 22 March 2016.

Therefore I am correct that in fact there were hobbyist sites installed much early on (i.e. two years prior to this date) but not recorded in your statistics?

I am just trying to work out back in 2014 for the various flights recorded around that time some details on the ground stations.

Thanks to your info I can now eliminate any Malaysian government owned radar sites and Malaysian government owned ADS-B ground based systems and now just want to know if they could possibly be Hobbyist sites.

12

The coverage map shows currently active sites only. The map in 2014 probably looked quite different, but because we don’t store historical snapshots of what it looked like in a readily accessible form (reconstructing a snapshot of receiver coverage in the past should be possible, but it’d require processing a bunch of historical data) I can’t help you with details of exactly what it looked like. The receiver network has grown substantially (order of magnitude difference) since 2014 and we generally ship FlightFeeders to areas that have poor existing coverage so you can perhaps approximate what the map used to look like by removing all FlightFeeders (yellow dots) installed after 2014.

13

Firstly thank you very much for answering all my questions. I just wonder if I could have a list of all the active ADSB-sites in Malaysia (with the approximate location of the site and site type either Flightaware owned or a Hobbists site). This split into two reports one as at 1/11/2013 and one for 1/12/2013. I would have thought that there would be only around about 10 ground stations per report.

If it is possible to extract from your database these reports could you let me know the cost for producing the same (This is assuming that you can offer this service). They can be in any format e.g. spreadsheet, CSV or in a standard report format.

e.g.
AS OF 1/11/2013
Site Name and Position Type
WMKK -------- Hobbist
WMSA -------- FlightAware

AS OF 1/12/2013
Site Name and Position Type
WMKK ------- Hobbist
WMSA ------- FlightAware
WMKP ------- FlightAware