The Piasecki HRP Rescuer family established the practical tandem-rotor helicopter as a transport and rescue architecture. Its PV-3/XHRP-X Dogship technology demonstrator proved the fore-and-aft rotor arrangement in 1945, leading to the U.S. Navy and Coast Guard HRP-1 and HRP-2 aircraft and a lineage that shaped later heavy-lift helicopters.
Future launches and major activity directly linked to this vehicle family.