Can new emission-free electric planes replace our pollutingairliners and revolutionize personal transportation in ourcities? NOVA takes you for a ride in some impressive prototypesthat are already in the air, from speedy single-seat planesthat can take off like a helicopter but are half as noisy to "self-flying" air taxis that already taking passengers on testflights in Chinese cities. But if electric airplanes are everto advance beyond small, short-haul craft, significanthurdles of battery weight, energy storage and cooling remainto be overcome. How long will it be before the dream ofsuper-quiet, super-efficient airliners becomes a reality?
