11 ms·

Not likely as I believe they turned off the transponder, which is what these devices listen for.

caf 10y ago
That's correct, in the case of MH370. ADS-B is essentially self-reporting.
nacnud 10y ago
Maybe the disappearance of the transponder signal could trigger another method of investigation, e.g. visual tracking via Planet Labs network of satellites.
verelo 10y ago
Planes have a variety of transponder options available, all of which can be turned on/off independently. Mode C (and sometimes Mode S) is the most common today and most important for entering controlled airspace (most airspace in the US is controlled). While ADS-B is an option, it's not yet mandatory (making its practical uses less than ideal in many cases). It won't be mandated until Jan 1 2020 in the US, and the first FAA laws on the ADS-B transponders were not published until May 2010. Source: https://www.faa.gov/nextgen/programs/adsb/faq/#g1 https://www.faa.gov/nextgen/programs/adsb/faq/#g1 ADS-B is amazing, yet I also find it's amazing it took so long to become more popular given how helpful it is. With an ADS-B receiver (I always have a stratus 2S on board while i fly) you get info like the call signs, speeds, positions and altitudes of other aircraft, while a Mode C transponder simply is a pinging beacon that air traffic can use to identify primary (radar based) targets. Mode C/S will give the pilot no advantage other than knowing that ATC can see them. Sadly in my case I only have an ADS-B receiver and no transmitter combined with a Mode C transponder, so i get some situational awareness and weather updates, but I do not contribute to the 'vision' of other pilots with my device. Stratus 2S: http://www.sportys.com/pilotshop/ipad-iphone-android/ipad-gps-and-weather/stratus-2s-ads-b-receiver-for-ipad.html/ http://www.sportys.com/pilotshop/ipad-iphone-android/ipad-gp...
- furyg3 10y ago
  Amazing. Maybe I'm extremely naive, but it seems to me that you shouldn't be able to turn the transponder off in a commercial passenger flight, and that international medium/long-haul flights that are likely to be in areas with reduced transponder coverage should be required to have some sort of Iridium beacon (which also cannot be turned off). Even sending the coordinates every 15 minutes would greatly reduce the area to search, and preventing disabling the transponder safeguards against nefarious or suicidal crew/passengers/terrorists. If I didn't know better (MH370), as a laymen I would have assumed all major flights would be sending their GPS locations constantly via satellite already, for a slew of reasons (one of them being it's 2016).
  - fbender 10y ago
    There's always a fuse you can pull. And there needs to be a fuse, per regulations on how to build aircraft. The stray MH370 signal was coming from the engines directly, presumably powered by the engine's internal power system, and it was engine performance telemetry to be sent to the engine manufacturer. The pilot might not have known about that system or unable to disable it (without shutting down the engines).
    - verelo 10y ago
      This is the key point, in the case that there is a fire on board (one of the likely possibilities with MH370) you want to be able to disable the offending circuit immediately. If that happened to be your transponder, so be it...the transponder really adds no value to the plane in terms of its ability to stay in the air, so disabling it and extinguishing the fire is the key priority over giving ATC the ability to identify you on radar via the transponder.
      - furyg3 10y ago
        But there can be a luggage fire? What fuse can you pull to disable that? I assume there are extinguishers for the luggage compartment? Put a GPS/Iridium suitcase in the plane?

caf 10y ago

That's correct, in the case of MH370. ADS-B is essentially self-reporting.

Maybe the disappearance of the transponder signal could trigger another method of investigation, e.g. visual tracking via Planet Labs network of satellites.

verelo 10y ago

Planes have a variety of transponder options available, all of which can be turned on/off independently. Mode C (and sometimes Mode S) is the most common today and most important for entering controlled airspace (most airspace in the US is controlled). While ADS-B is an option, it's not yet mandatory (making its practical uses less than ideal in many cases). It won't be mandated until Jan 1 2020 in the US, and the first FAA laws on the ADS-B transponders were not published until May 2010. Source: https://www.faa.gov/nextgen/programs/adsb/faq/#g1 https://www.faa.gov/nextgen/programs/adsb/faq/#g1 ADS-B is amazing, yet I also find it's amazing it took so long to become more popular given how helpful it is. With an ADS-B receiver (I always have a stratus 2S on board while i fly) you get info like the call signs, speeds, positions and altitudes of other aircraft, while a Mode C transponder simply is a pinging beacon that air traffic can use to identify primary (radar based) targets. Mode C/S will give the pilot no advantage other than knowing that ATC can see them. Sadly in my case I only have an ADS-B receiver and no transmitter combined with a Mode C transponder, so i get some situational awareness and weather updates, but I do not contribute to the 'vision' of other pilots with my device. Stratus 2S: http://www.sportys.com/pilotshop/ipad-iphone-android/ipad-gps-and-weather/stratus-2s-ads-b-receiver-for-ipad.html/ http://www.sportys.com/pilotshop/ipad-iphone-android/ipad-gp...

furyg3 10y ago
Amazing. Maybe I'm extremely naive, but it seems to me that you shouldn't be able to turn the transponder off in a commercial passenger flight, and that international medium/long-haul flights that are likely to be in areas with reduced transponder coverage should be required to have some sort of Iridium beacon (which also cannot be turned off). Even sending the coordinates every 15 minutes would greatly reduce the area to search, and preventing disabling the transponder safeguards against nefarious or suicidal crew/passengers/terrorists. If I didn't know better (MH370), as a laymen I would have assumed all major flights would be sending their GPS locations constantly via satellite already, for a slew of reasons (one of them being it's 2016).
- fbender 10y ago
  There's always a fuse you can pull. And there needs to be a fuse, per regulations on how to build aircraft. The stray MH370 signal was coming from the engines directly, presumably powered by the engine's internal power system, and it was engine performance telemetry to be sent to the engine manufacturer. The pilot might not have known about that system or unable to disable it (without shutting down the engines).
  - verelo 10y ago
    This is the key point, in the case that there is a fire on board (one of the likely possibilities with MH370) you want to be able to disable the offending circuit immediately. If that happened to be your transponder, so be it...the transponder really adds no value to the plane in terms of its ability to stay in the air, so disabling it and extinguishing the fire is the key priority over giving ATC the ability to identify you on radar via the transponder.
    - furyg3 10y ago
      But there can be a luggage fire? What fuse can you pull to disable that? I assume there are extinguishers for the luggage compartment? Put a GPS/Iridium suitcase in the plane?