UH-60 Blackhawk helicopters are the most common in the U.S. Army; they are one clan of a large family of H-60 series helicopters used by all services except the U.S. Marine Corps. They replaced the UH-1, officially the "Iroquois" but invariably known as the "Huey", iconic of the Vietnam War. Blackhawks are a light to medium capacity design used for troop transport, aeromedical evacuation, command and control, and various specialized tasks. Depending on the mission, they may be armed helicopters, but dedicated attack helicopter variants are not used in conventional Army operations.
Blackhawks have evolved considerably since the original version built for the U.S. Army, the first model of which was built in 1978. No fundamentally new helicopter replacement is planned for the regular Army; the M-level, standard for new manufacturing, is also a rebuild and life extension of older airframes.
As would be expected, the first model was the "A", although there soon were a number of derivatives. There were a number of A-model utility transports, many exported, and the EH-60C SIGINT platform with the "Quickfix" signals intelligence (SIGINT) and electronic warfare (EW) emitter location and targeting system.
Second generation Army
The underpowered A models first became the base UH-60L, with an improved engine and transmission.
Aeroedical evacuation versions were the UH-60Q, and the improved HH-60L.
A and L models were moved to M level, with structural improvements, digital cockpit, and an engine upgrade.
The HH-60M was the improved medevac version and the UH-60I had an Army Airborne Command and Control System.
EW and SIGINT have moved to unmanned aerial vehicle platforms.