And yet efficiency gains are vigorously pursued and adopted, where real - and most recently, that has been with engines and composites. Meanwhile, the blended-w

And yet efficiency gains are vigorously pursued and adopted, where real - and most recently, that has been with engines and composites. Meanwhile, the blended-wing concept has been experimented with for over a century, and it has never demonstrated a compelling improvement. Until I see a proposal that comes with a paper explaining what recent innovation has made things different this time, I will remain skeptical.