Venanzi said autorotation tests have been conducted at altitude, and that “it doesn’t take much altitude” to achieve a power-off full flair to a sink rate of zero fpm.
Agusta Test Piot Veranzi talking of flight tests on the Civil Tiltrotor.
What about the Osprey.....isn't 1,600 feet the number given for the ability to achieve forward airspeed for a fixed wing type emergency landing and no ability to "auto-rotate"?
Certification requirements?
Safety standard criteria difference?
Design difference?