Thursday, June 17, 2010

Of the Fear and Joy of Flying

For me, I have two thoughts about flying. First, the views from flight can be spectacular, being up with the clouds and looking down on fields and farms and cities and mountains. And then there’s the anxiety and sweaty palms that comes during turbulence and rough landings.

Last week, I took to the airways for the first time in a year for a family wedding. It was a week that can be summed up by saying life sometimes passes faster than we can appreciate it. One day, I’m in tears as my youngest is graduating from high school (my baby boy is grown up!) and the next day we’re up before the dawn to fly west. And we left our graduate with his brother, hoping they would eat something nutritious, wash a few dishes, feed the cats, and keep the house in some condition that we might recognize when we returned.

Flying is something I’m a little reluctant about. As an engineer, I usually know how things work. In fact, in many cases, I know the equations and have run the calculations. I can figure out how much to bank a curve for 60 mph. I had to figure out the forces in each member of a truss bridge. I can figure out how big to make a drain pipe.

But I never learned the equations for flight, so I always worry: How does it stay up in the air? I know all about the velocity vectors and how to calculate the arc of a baseball traveling 90 mph and leaving the bat at an angle of 90 degrees. But the baseball soon falls to the ground, while a place stays up there for hours.

I’ve heard about “lift” and somehow the forward velocity of the plane combined with the wing angle actually causes it to go up despite the relentless pull of gravity that brings all things down to earth, eventually.

So, on takeoff, particularly, I’m imaging all these velocity vectors and force diagrams and I'm rooting with all my strength that the “lift” term in the equation wins out of the force of gravity. (Otherwise it would be a very short flight!)

But this is why I prefer to drive or take the train: I know the equations and I know how it works!

Despite my uneasiness, I must say that flight is one of the great marvels of human accomplishment. To be able to soar above the clouds and gaze down at the earth 30,000 or 40,000 feet (0.9 to 1.3 km) below! To see towering, fluffy clouds from above! To see amazing sunsets or sunrises appearing in elongated landscape format! How inspirational it must be for artists.

No sooner than a day later, I was at the Georgia O’Keeffe Museum in Santa Fe. And there on exhibit was her Sky Above Clouds III/Above the Clouds III (1963). There is that unique view of the dusky horizon. And what a creative presentation of cloud tops, appearing like white lily pads clustered on a broad pond. The view is almost other-worldly. More about Georgia O’Keeffe in another post!

3 comments:

I Love-Hate America by Bing said...

I'd rather fly than drive or take the train. I'm a very antsy traveler....I can't wait to get to my destination. If I can have a superpower, I would like to have the powers of Nightcrawler---teleportation. He can transport himself from one place to another without occupying the space in between.

Ed May said...

Hi Rachael,

I came to your blog from Suzanne Vega's site. Nice to meet a new fan.
I'm an occasional pilot. The airplane flies because the forces of lift counterbalance gravity, and the thrust of the engines balances the induced drag created by lift and the parasitic drag of the airframe. The shape of the wing causes airflow over the top of the wing to be accelerated as it rejoins the air beneath the wing, resulting in a force vector that imparts an upward trajectory to the airplane. Thrust may be provided by engines to maintain level flight, or in the case of a sailplane, by the energy of rising air in thermals to exceed the drag of the airplane, allowing the glider to climb without engine power. The Wright brothers were the first to understand the dynamics of powered flight, and so invented the airplane. Helicopters use a wing rotating in a horizontal plane to the same end.
Hope that makes you feel better. As long as an airplane can maintain a speed above its stall speed (when lift vanishes), it will continue to fly under control, so even power off all airplanes are controllable. You just look for a place to land. This even applies to the space shuttle, which is a glider with a very low glide ratio as it approaches the runway from orbit.

Ed (islandflyer)

Rachy said...

Ed,

Thank you for the explaination of how the balance of forces keeps a plane in the air. As I said, I'm always rooting for that "lift" and I guess I should also root for v > stall speed!

Nice to meet you and hope to hear from you again!

Rachel