Improved prototype of the HRP-1 Type series used for U.S. Navy trials and for static and dynamic tests. 2 were built.
The XHRP-1 was noticeably different from the XHRP-X by having a more bowed, curved windscreen (see link).
Latest or last design authority:
Piasecki Helicopter Corporation
Originally designed by P-V Engineering Forum
Primary manufacturer: P-V Engineering Forum
Parent type: P-V Engineering Forum PV-3/HRP-1
Aircraft status: No longer flying
VTOL type: Helicopter
Lift devices: 2 in Tandem (Fore/aft) configuration
Crew required: 2 in Other arrangement
Landing gear: Wheels (non-retractable)