Distributed electric propulsion

Spreading many small electric motors and propellers across an airframe instead of relying on one or two large engines.

• Combustion engines lose efficiency as they shrink, but electric motors stay above 90% efficient at small sizes, so many small ones is practical.
• Power travels by wire, so propellers can go where they help most, such as along the wing, blowing air over it for extra lift at low speed.
• Benefits include redundancy if a motor fails, shorter takeoffs, and potentially lower noise from slower-spinning propellers.
• Costs: more motors, controllers and cooling to certify, complex coordinated control, and range still capped by batteries.