Originally Posted by
JohnDixson
CTR-any idea what the auto descent rate is at max weight? Ditto for auto Nr?
Also, did the certification authority require an autorotation landing?
Like the V-22, the 609 has the ability to perform a run on landing in the event AEO. So for certification I recall it being a marketing plus, not a requirement.
The aircraft max weight has grown since AW took over responsibility, so I cannot state if it is possible at max weight.
When Bell test pilot Roy Hopkins flew the simulated auto rotation test flight, he throttled both engines back in airplane mode, proceeded to go through emergency reconversion to VTOL mode, the simulated and autorotation to ground landing at a safe altitude to allow recovery. Looking at the telemetry altitude traces, upon first flaring for the autorotation landing the aircraft actually gained altitude and required lowering the collective to finally land.
The 609 minimum Nr is actually more critical to maintaining support to the fly by wire systems continued operation versus adequate kinetic energy for auto rotation. When reconverting to VTOL excessive Nr decay from lack of air flow windmilling the rotors can cause generators and pumps to go off-line.