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British Airways secret flights?

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  • British Airways secret flights?

    Does anyone know why BA flights turn off their SBS about 50 miles from destination? I spot at Alicante airport where I can see the landing A/c about 2-3 minutes from touchdown. The daily BA flight from LGW switches off it's SBS before it clears the mountains and only by dead reckoning from arrival time can I ever see it. I have noticed that Air Nostrum (a BA subsidiary) also does the same. Of the many airlines from all over Europe and N Africa that operate to/from Alicante, these are the only "secret" aircraft. Note; Flybe do the same at Exeter.

  • #2
    What radar ID do you see for these flights? T-MLAT by any chance?

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    • #3
      I have never noticed the radar ID. What difference would it make?

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      • #4
        The MLAT (T-MLAT, T-MLAT1 T-MLATx etc) doesn't have good coverage near the ground/lower altitude coverage in most areas.
        Since it requires multiple FR24 receivers picking up the aircraft signal to do MLAT.

        More info about it on this page.
        http://www.flightradar24.com/how-it-works
        Last edited by SoCalBrian; 2014-08-04, 19:19.
        Brian

        www.RadarSpotters.eu
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        • #5
          BA secret flights.

          Thanks for the reply. I read the article about MLAT; interesting but doesn't answer the question about why BA turn off their equipment about 50 miles from destination. There are around 200 movements per day at Alicante, all of which are tracked to and from the ground on takeoff and landing so height doesn't come into the equation . The exceptions being British Airways and Air Nostrum (a BA subsidiary) which always disappear about 50 miles away and cannot be tracked close to the airport. Even the Russians are fully tracked (S7 Siberian flights).

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          • #6
            Please check these BA aircraft before they "turn off" their transponders and look what Radar is shown in the aircraft details panel. My guess it's T-MLAT.

            Or let us know the registrations and aircraft types.

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            • #7
              BA secret flights

              Yesterday; Monday 4th August 2014, Flight BA2632 flown by G-DOCO Boeing 737-436 from LGW to ALC arrival time 13.47 GMT. Ident switched off as it passed Villena, NW of Alicante, approx 13.35 GT.

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              • #8
                Thanks.

                That aircraft doesn't send positional data and is tracked using MLAT which explains why we cannot track it inbound on the descent into Alicante where we don't have MLAT coverage.

                BA is not switching anything "off".

                Here it is arriving Gatwick at this time. You will see the Radar is T-MLAT as expected.

                01.jpg

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                • #9
                  BA secret flights

                  Thank you very much for the explanations. Why do BA and Air Nostrum appear to be the only airlines using M-LAT and not DBS ?

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                  • #10
                    MLAT is not "used by airlines".

                    It's a feature of the Flightradar24 (and Radarcape) receivers that can "track" aircraft that do not transmit positional data.

                    See How it Works for more information about MLAT.

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                    • #11
                      Originally posted by Tony15 View Post
                      Why do BA and Air Nostrum appear to be the only airlines using M-LAT and not DBS ?
                      Presumably you mean SBS and not DBS
                      SBS is not a mode, anyway. It's a 'receive-only' piece of hardware/software

                      TSOM

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                      • #12
                        The Sage is correct, aircraft are not fitted with an SBS, they are fitted with a transponder. An SBS is a piece of equipment a person on the ground can use to receive and decode the signals sent out from the aircraft's transponder.

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