The most numerous military helicopter in the air on any given day. Live UH-60, MH-60 and HH-60 positions worldwide.
The H60 designator covers the whole Sikorsky S-70 family, and between the Army's UH-60s, the Navy's MH-60R and S, the Air Force's HH-60 rescue helicopters and dozens of export operators, it is usually the most numerous single type on the feed after the Hercules.
Helicopters behave differently from everything else here. Sorties are short, altitudes are low, and coverage is patchy because ADS-B reception depends on line of sight — a helicopter at 500 feet is invisible to a receiver twenty miles away that would hear a jet at 35,000 feet easily. The live count on this page therefore undercounts the fleet more than a transport page does.
What you do see tends to cluster around bases and training areas, which is its own kind of information.
ADS-B needs line of sight to a ground receiver. A helicopter operating at a few hundred feet is behind the horizon for almost every station that is not very close by, so a large share of rotary traffic is simply never heard.
UH-60 is the Army utility version. MH-60R and MH-60S are Navy variants for anti-submarine work and shipboard support; the HH-60 is the Air Force combat rescue version. All share the H60 designator on this site.
It is the US Army's medical evacuation callsign, in use since Vietnam. A DUSTOFF flight is a medevac, though in peacetime that frequently means training rather than a live casualty.