This is the one really stupid rule if correct. The whole idea of RVSM is to increase the airspace above FL290 so the big jets don't have to cruise at the lower flight levels where gas mileage is not good. We're using RVSM over the Pacific and the Atlantic. Everyone fights for the higher flight levels. Remember we're talking about the government bureaucrats in the process of making up rules. Reserving the airspace between FL190 and FL270 for big jets will render the space empty.

 

Dave Link.