A Flightradar 24-en a mentőhelikopterek miért nem jelennek meg?

Mert elméletben nincs bennük az a szenzor, ami ehhez kell. A Flightradar oldala legalábbis ezt írja:

"FlightRadar and similar websites use several sources for aircraft detection, most commonly they use ADS-B. Not all General Aviation aircraft, to which helicopters would count normally, are equipped with transponders that are capable of emitting ADS-B data, so they would not show via regular means on FlightRadar "