PANews, a NOTAR-like system that uses 'hot efflux from the engine'? What if the engines quit?
Don't ask me! I am only the messenger.
Like many others to me the real technology of this 'notar like' system remains a mystery. Perhaps that is just how Bell want it. After all they were not exactly forthcoming with the reasons they dumped the fenestron. They probably have 'Commercial Confidential' issues!
A certain company once claimed to the effect that its system removed the danger of tail rotor failure. But then lost an airframe because the fan failed and the Coanda effect was not enough on the day. So even if we are talking about 'hot efflux from the engine' it would be no different to any other system when the fire went out and the t/r lost effect.
There are plenty of t/r failures that do not lead to undue drama and plenty of types that do not really sit in the hover because their recovery profile is not exactly docile. Similarly forward speed may remove the element of danger when the fire goes out to the 'new Bell system' as well as it does for airframes today.
I guess we will get the explanation of the technology when Bell are good and ready.
Thats assuming they even know themselves!