To: diethelm
Two reasons (among many others) come to mind. The level of reliability does not meet the requirements for a presidential helicopter (Powered lift aircraft) and in the helicopter mode it can’t autorotate. Its rate of descent is 4-6000 feet per minute. When in the airplane mode it was assumed that the hydraulic servos would only be used to control the pitch of the Prop Rotor ™ which would be minimal however the design of the Prop Rotor ™ allows it to move due to gyroscopic forces during maneuvering causing a high demand on the hydraulic system effecting it’s reliability.
