ggrosskopf wrote:
The modern slide rule was invented in the mid-1800s. NACA didn't come along until 1915. And how do you think they determined the performance characteristics of the various airfoil shapes? They took pictures of the colored smoke flowing around them in wind tunnels, and THEN did the calculations.
George
Exactly. This would NOT be completely impossible without the photography and electrical sensors&controls for test equipment, but it would be very, VERY hard to do. Either it would took decades to just obtain the basic data, or Merlin&Co would be forced to deal with complete implausibility of their own "someone just invented this, honest!".