Where are your figures for energy efficiency? (Recalling that the comparison should be for the same speed, or energy per kilogram transported for a kilometer given the optimal speed tradeoff).
A Harpy Eagle can lift more than three-quarters of its body weight while the Boeing 747 Large Cargo Freighter has a maximum take-off weight of almost double its operating empty weight. I suspect that insects can do better. But my whole point is that we never reached artificial flight that is strongly above the level of natural flight. An eagle can after all catch its cargo under various circumstances like the slope of a mountain or from under the surface of water, thanks to its superior maneuverability.
Where are your figures for energy efficiency? (Recalling that the comparison should be for the same speed, or energy per kilogram transported for a kilometer given the optimal speed tradeoff).
A Harpy Eagle can lift more than three-quarters of its body weight while the Boeing 747 Large Cargo Freighter has a maximum take-off weight of almost double its operating empty weight. I suspect that insects can do better. But my whole point is that we never reached artificial flight that is strongly above the level of natural flight. An eagle can after all catch its cargo under various circumstances like the slope of a mountain or from under the surface of water, thanks to its superior maneuverability.