Insights

I have always been fascinated by the wings of airplanes I’ve flown. Subtle refinements have increased performance and changed pitch-attitude management. I started with my old Aeronca’s Clark Y airfoil, a design that you usually see in illustrations: A flat bottom with a large-radius leading edge that bends back and gradually rises for about one-third of the wing’s chord line before tapering down to the wing’s trailing edge.

Next came the Piper Comanche’s laminar flow wing, a thinner wing that delayed airflow separation. The Army’s deHavilland Beavers and Caribous had 40-degree flaps and drooping ailerons that increased the camber of the entire wing for slow-speed approaches. The twin-engine Caribou’s wing was interesting because outboard of each engine nacelle was a fence that separated two entirely different wing sections: low-speed performance inboard; high-speed performance outboard. At its 32,000-pound gross weight, it could easily operate out of a 1,500-foot runway.

The Boeing 727 wing was beautiful. It had the most wing-sweep of any airliner of that era, and it was perfectly clean. No vortex generators, fences, or engine pylons—the three Pratt and Whitney JT8D turbine engines were mounted in and on the aft fuselage. Wings with vortex generators—small tabs located atop the wing in order to slow down air movement and delay airflow separation—are the ugliest of all.

The fiber-composite Airbus A320—the most technologically advanced airliner at its inception—had a spectacular wing. Because it was cast in a mold, it was shaped to perfection, something that would be difficult and quite expensive with an all-metal wing. This wing resembled a supercritical airfoil because the upper surface was flattened somewhat; the leading edge had a relatively large radius; and the bottom of the wing’s rear section was highly cambered, just like a bird’s wing. The efficiency of this wing was amazing.

Several of our newer light airplanes and light sport airplanes are fiber composite, and they too reflect the efficiencies of the new technology where wings are molded to perfection. The high-wing light sport airplane that I’ve been flying has a beautiful cantilevered wing. Every inch is gracefully cambered, including the 40-degree flaps and the drooping ailerons—as is the fiber composite, three-blade propeller. What’s the advantage? True airspeed, 112 knots at 75-percent power; fuel burn, 4.7 gallons per hour.

I mentioned pitch attitude management changes. With older metal wings I’ve always taught students that there are several pitch attitudes for normal flight: best-angle climb; best-rate climb; cruise climb and slow cruise; cruise; power-on landing approach and best glide; and cruise descent and power-off landing approach. The word pitch has five letters, so I call them the P-I-T-C-H attitudes.

The starting point for any of those maneuvers is the desired attitude using the wing’s imaginary chord line in reference to the horizon and the proper power setting. Remember the old adage: Attitude plus power equals performance. Start those maneuvers using the proper attitude and power setting, and you are flying safely. Perfectly? Probably not. So quickly glance inside the cockpit at the proper instrument, look back outside, and make a small attitude or power adjustment if a correction is needed. It won’t take much. If you stare at that instrument while making the correction, you’ll overcontrol the airplane.

To understand the five pitch attitudes, hold your left hand in front of you so that your thumb is on top and you’re looking at the palm. Spread your thumb and fingers slightly apart and rotate your hand so that your ring finger is parallel to the floor. Your fingers now represent the pitch attitudes. Now rotate your hand slightly clockwise and spread your thumb and fingers a little farther apart. That’s what you’ll see with the new fiber-composite wings. With the exception of cruise, the attitude for the other maneuvers will differ slightly from what you’ve experienced with metal wings.

Try flying a light sport airplane. You’ll be surprised. They require enhanced attitude and power management during all phases of flight and acute awareness of sink rate and lateral drift during landing.

The Cessna 150 with its 40-degree flaps was my favorite tricycle-gear training airplane—tailwheel airplanes are even better—because every gust of wind would knock you silly. Light sport airplanes require a higher skill level, because that same wind gust will now knock you willy-nilly. Don’t give up. After a few flights, your stick-and-rudder and attitude management skills will improve dramatically.