This thread was started in September, I think the original reply time has passed for their decision, so what was the resolution to this situation/problem? Or has the gas been flowing flameless since September?
As to the R/C aircraft, if the gas in the area displaces the oxygen, would the engine still run in a no or low oxygen atmosphere? Would be a real bummer to start flying the aircraft toward the stack only to have the engine flameout and the aircraft come to rest in the no-man's zone without accomplishing it's mission. Then you'd have two issues to deal with, getting the aircraft out of the clear zone and still needing to ignite the flume.
So, anyway, what's happened since September??????