Speaking of sustainable fuels, Yars, I notice that they had nothing to say about unleaded Avgas, sustainable or not. I guess the NBAA regards piston power as beneath their radar. Taking the lead out of airplane fuel would have a big economic impact on 90% of the airplanes flying today. It would promote longer engine life, greatly reduce spark plug and valve guide fouling and get the lead freaks off our backs. But, I guess that form of environmental consciousness doesn’t get their attention.