Agreed, GP is way too optimistic. Airplane manufacturing peaked in the late 1970s with over 18,000 planes manufactured a year. These days the numbers are under

Agreed, GP is way too optimistic. Airplane manufacturing peaked in the late 1970s with over 18,000 planes manufactured a year. These days the numbers are under 3,000 planes a year! Switching to a new power source isn't going to change the fundamental economics of airplane manufacturing. There just isn't enough demand to reach any kind of scale and it's not the gas prices - manufacturing collapsed to its lowest point in the early 1990s before gas prices went out of control.