Frank Piasecki's First Production Helicopter, the HRP-1 Rescuer

During World War II, the Navy contracted with the P-V Engineering Forum headed by Frank Piasecki for a challenging Coast Guard maritime-rescue requirement: hoisting a maximum of eight survivors (one at a time) from the sea following the sinking of a ship. This necessitated a useful-load requirement of about 2,000 lbs (900 kg), almost twice that provided by any helicopter then under development or in service. Both the tandem-rotor configuration and the selection of P-V were audacious choices because the former was unproven and latter's only experience was the development of a small (1,000lb/450-kg), one-off, single-seat helicopter with a single main rotor and a separate side-mounted anti-torque tail rotor. However, the three most prominent American helicopter companies—Platt-LePage, Sikorsky, and Kellett—were already fully involved with their existing projects, the R-1, R-4/5/6, and R-8 respectively. The subsequent successful and relatively trouble-free development of the XHRP-X (H for helicopter, R for transport, P for P-V Forum) proved the feasibility and benefits of the tandem-rotor configuration as well as P-V's design and development capability, resulting in the go-ahead for a prototype XHRP-1 and then production contracts for 20 HRP-1 Rescuers, small in number and too late for use in World War II but a significant investment by the Navy given post-war budget cuts. As a result, the U.S. Navy, Marine Corps, and Coast Guard were provided with a large transport helicopter that was used to very effectively demonstrate the feasibility and benefit of more missions than its raison d'etre, maritime-rescue, and a company was established that has produced tandem-rotor helicopters for the U.S. military as well as civil operators worldwide and foreign military services for more than 70 years.