BIRDS that soar can stay airborne with minimum effort. The wandering albatross is an outstanding example. With a wingspan of 11 feet (3.4 m) and weighing nearly 20 pounds (8.5 kg), this bird can fly thousands of miles using very little energy! Its secret lies in both its anatomy and its soaring technique.
During flight, an albatross engages special tendons that lock its wings in place when fully extended, thus allowing the muscles to rest. The bird’s other secret
At sea, albatrosses climb, turn, and descend in continually repeated arcs
These insights may help engineers design aerial vehicles that are more fuel efficient, perhaps even using engineless propulsion.