Re: Owls
"Less joyously, this sort of nonsense comes round every ten years. Last time it was Cambridge with some big aerospace boondoggle to develop silent flight. I think results so far are nil."
I suspect the problem is no one is really building new planes. A new plane takes many years from concept to service-ready, so most new planes are adaptions and improvements on older models, thus seriously reducing the development and certification phases.
The research ideally needs to come up with simple adaptions that can be retrofitted to existing planes which then must be mandated in at least some jurisdictions, forcing the manufactures, owners and operators to take it seriously. They won't spend money they don't have to unless there are savings to be made in one opr more of fuel economy, lifting capacity or fine avoidance.