Wings perform marvelous feats. With them we soar like eagles and race with the wind. Without them we wish. With them we cross continents, leap oceans, and vault mountains. Without them we walk.
We tried for a long, long time to understand them, to imitate them. But, exactly how wings carried birds, bats, and bees aloft remained an enigma until 1799 when Sir George Cayley described the four basic forces of flight: lift, weight, thrust, and drag.
Suddenly, we knew. Wings produce their mysterious lift simply by their shape. Slicing an orange in half reveals a circle. Slicing a wing shows a special shape called an airfoil. Air flowing over an airfoil produces a low pressure area above the wing and a high pressure area underneath. High-pressure pushes the wing up into the low-pressure area and, voilá, we have lift.
Mystery solved, right? Well, partially. Airfoils have two different curves, one on top and the other on the bottom. The difference between the two curves is called camber. The greater the difference between those curves, the greater the camber. A wing’s camber, it turns out, determines what kind of flying it’s good at.
For example, early airfoils like the “Wright Flyer” imitated bird wings. Both upper and lower surfaces are highly curved, but almost parallel to each other. They produce a lot of lift, but aren’t very fast. Others, like the “P51,” work well at high speed, but not so well at slower landing speeds. The “NASA GAW2” enables airliners to fly efficiently just below the speed of sound. And the “Clark Y” airfoil serves MAF Cessna 206s flying at moderate speeds.
Just as engineers design different wings for different jobs, so God designs each of us for the jobs he assigns. Some are actors, others bakers. Some are mothers or preachers, others are gardeners or pilots, each equipped with exactly the right wings. There is, however, one caveat.
Wings only work when moving. Airplanes don’t fly until the pilot starts the motor. We don’t fly until we obey.
But they who wait for the Lord shall renew their strength;
they shall mount up with wings like eagles;
they shall run and not be weary;
they shall walk and not faint. – Isaiah 40:31
