On the subject of GND mode, I think it is firmware-version dependent; newer firmwares don’t have it anymore, in line with evolution of regulatory requirements. I can’t immediately find back where I read that, though.
Under the rug: having a phone with SD on top of an ADF is a must, the aircraft I did use in the IRR test had that only sense the NDB at 4nm range,
Assuming visual, to fly overhead from a 50nm leg on that will need to be really good in DR nav, so it can only make it better ;)
Ibra wrote:
On a similar line, good luck explaining to the FAA that you can use today mobile phones inside CAT cabins on takeoff/landings (if you think a 100$ smartphone will interfere with a 50m$ aircraft equipment then you are in the wrong forum)
I recall that there is one (at least) documented instance where a $100 (or thereabouts) CD player did affect the onboard NAV equipment of a $50m (or thereabouts) airliner.
Ibra wrote
if you think a 100$ smartphone will interfere with a 50m$ aircraft equipment then you are in the wrong forum
We had a (nontechnical) discussion about this… I think the only instrument that might be affected is the ADF, which no one uses, and even then not sure
On a similar line, good luck explaining to the FAA that you can use today mobile phones inside CAT cabins on takeoff/landings (if you think a 100$ smartphone will interfere with a 50m$ aircraft equipment then you are in the wrong forum)
The reason is probably lost in the mists of time. Like the reason for not using radios in the vicinity of refuelling, which dates back to the time of spark-gap transmitters, which went out of fashion in the early 1920s.
I think this could be an old tale. Why would you squawk SBY when changing the codes? The only reason as mentioned above is to avoid keying 7×00 by accident.
In a commercial aircraft you often get different squawk when changing the boundaries or entering an oceanic route, and by putting the xponder to standby you’d be momentarily turning off the TA/RA Tcas mode, which is of no benefit
Ibra wrote:
In big airports, GND ATC already have movement sensors detectors/magnetic sensors (like GATS) or surface radar grids (ASDE-X in USA) to use for ground surveillance but I am not sure if TWR ATC will be interested in seeing that much of traffic on their primary/secondary radars unless it crosses their runways?
All airports I’ve seen that have mode S ground radar requests that on departure it is turned on in GND mode at block off and on arrival kept in GND mode until the aircraft is parked.
JasonC wrote:
Like ground control at most major airports?…..There is no downside. Why not use it if you have it?
Got it, so mainly a limitation of Flarm/FlightAware not being able to filter out ground traffic (unlike TCAS as you mentioned)
In big airports, GND ATC already have movement sensors detectors/magnetic sensors (like GATS) or surface radar grids (ASDE-X in USA) to use for ground surveillance but I am not sure if TWR ATC will be interested in seeing that much of traffic on their primary/secondary radars unless it crosses their runways?
Ibra wrote:
Personally, I hate when I get FlightAware/Flarm notidfications while on circuit/final due to traffic sitting on the ground
You shouldn’t get any warnings when the transponder is in GND mode. That’s the point!
