The West's standard attack helicopter. Live AH-64 Apache positions, where they transmit at all.
The Apache is the aircraft most people picture when they think of an attack helicopter, and with good reason: around 2,500 have been built and it is the standard type for the US Army and a dozen allied forces including Britain, the Netherlands, Egypt, Israel, India, Japan and South Korea.
It appears here less than its numbers suggest, and for two reasons. Attack helicopters fly low, which limits ADS-B reception, and they operate on training ranges rather than through civil airspace, where transponder use is expected. Dutch and British Apaches are among the more consistent transmitters.
The current AH-64E Guardian is a substantial rework with more powerful engines, composite rotor blades and the ability to control drones from the cockpit.
Attack helicopters fly low and mostly over military ranges, so there is little reason to transmit and little chance of a ground receiver hearing them if they do. A zero on this page is the normal reading.
The E has more powerful engines, composite main rotor blades, better networking and the ability to control unmanned aircraft. Both share the H64 designator here.
The Longbow fire control radar. It sits above the rotor so the aircraft can hide behind terrain and still see over it, exposing only the radar.