None of the Flight tracking websites are perfect - they all have their problems. They are mostly very good for general civil aircraft movements because there isn't really any requirement to disguise what is going on. I'm not really interested in civil - other than to know if my TUi B737 has actually landed at Exeter/Bristol ready for my 6AM tomorrow morning flight.
Military coverage is where it's at for me, and Flightradar/FR24 is probably the worst for that. In order to get access to official FAA radar feeds they have had to agree to mask sensitive flights from public view. Sensitive has expanded to include most Military and even some biz-jets operated by multi-millionaires.
Incase you don't know, ModeS tracking ony requires that an aircraft transmits it's "unique" 24 bit number, it's callsign, it's altitude, and it's squawk. They NEVER transmit their tail number or type. In addition if an aircraft is ADSB enabled it can also transmit it's latitude and longitude. Most military aircraft nowadays are fitted with all of the above (full ADSB), but many of them fly with the ADSB turned off. Therefore all you get is callsign, altitude and the "unique" 24 bit number.
It requires a database to convert the 24 bit numbers (called ICAO codes) to aircraft tail numbers/serials so know what the aircraft is. The vast majority of civil aircraft use a 'static' number - they are allocated the number by the state they're registered in.
Many Military aircraft also use 'static' allocations, but 'dynamic' allocation is becoming more common, particularly on US navy P-8's and USAF F-15's. RAF F-35Bs rarely show on Mode S, but when they do they always show as tail number ZM150 and callsign "F35LGHTNG", which means that all of them seen to date are using the same 24 bit ICAO code.
hypothetically speaking though, if an aircraft can so readily be (mis)identified as something it isn't, what's to say that MH17 didn't land on Diego Garcia as a Gulfstream? 🤔
Absolutely nothing. ModeS/ADSB data only shows what is probably up there, and if someone is determined to spoof the system its relatively easy to do so. The only way to know for sure is for someone to get eyes-on and read the tail number off.
Incidentally isn't Air Force One technically the call sign of whatever the President happens to be flying on board? The converted 747 being what people consider the generic presidential aircraft...
Yes. Whenever POTUS flies on a USAF operated aircraft the callsign is AF1. Doesn't matter if it's a VC-25, C-32, C-17, C-130, if POTUS is on board it's AF1. If he's in a US Marine corps aircraft (such as the VH3 helicopters) then the call-sign is Marine1. And if he's on a US Navy Aircraft, its Navy1.
There are very rare exceptions. Trips into Iraq/Afghanistan to see the troops are usually disguised. On one recent trip the VC-25 used an ICAO code and callsign (Reach) more normally allocated to a C-17 transport planes. Trouble is, cover was blown when someone took a photo of it flying over northern England - Difficult to mistake a VC-25.