Bill Crawford’s Flightlab Blog

Sometime ago I lent a student my Dad’s old bedraggled copy of Wolfgang Langewiesche’s classic Stick and Rudder, and got two copies back. The original copy was looking like it might have gone through the prop, so including a fresh one when he returned it was a nice gesture on the student’s part. He enclosed a note saying that he had read it cover to cover three times. Not a lot of books—on anything—live up to three encounters. I remember reading Stick and Rudder as a beginning pilot and thinking afterwards that I was starting to understand stuff. It was fun to read it again over the December holidays, and still experience revelation.

Stick and Rudder goes back to a time when airplanes went in proper miles-per-hour, like cars and buses. It came out originally in 1944, and was based on articles written earlier for the magazine “Air Facts.” Before it became a magazine, “Air Facts” was a monthly information service analyzing aircraft accidents. As a magazine, “Air Facts” maintained its emphasis on safety issues. I read Dad’s copies when I was a kid. Thanks to its editor, Leighton Collins, I was better informed on the nuances of wheel landings versus three-pointers than any other boy in third grade.

Collins’ friend Langewiesche thought that safety was largely a matter of overcoming the “established habits of mind and body” that lead to accidents. As he pointed out at the beginning of Stick and Rudder, “In many important respects, a wing’s behavior is exactly contrary to common sense. On wings it is safe to be high, dangerous to be low; safe to go fast, dangerous to go slow. Generally speaking, if you want the airplane to go up, you point its nose up; but point its nose up a little too much, and you go down in a stall or a spin. In landing an airplane, to make it sink down on the runway and stay down, you move the controls much as for an extreme upward zoom. In the glide, if you want to descend more steeply, you point your nose down less steeply; if you want to descend less steeply, you put your nose down more steeply! And—most spectacular contrariness of all—in emergencies, when the airplane is sinking toward the ground in a “mush” or falling in a stall or a spin, and you are afraid of crashing into the ground, the only way to keep it from crashing is to point its nose down and dive at the ground, as if you wanted to crash!”

There’s a lot of fundamental airmanship in those words, and I’m a sucker for any author to whom the grease-stained muse of aviation prose whispers a phrase like “spectacular contrariness” to characterize aircraft behavior. “It’s the contrariness of the airplane,” Langewiesche writes, “that makes flying so difficult to learn.” He meant by this a “contrariness to common sense” and to natural instinct. What made learning to fly more difficult than learning many other complex tasks were all the “established habits of mind and body” that had to be unlearned in the process.

Langewiesche understood that replacing established habits with appropriate responses was in part a matter of drill—enough repetition so that new response habits could shoulder aside the instinctive ones that simply don’t work when you build a machine with wings. But he also thought that flying was difficult to learn because pilots worked from an inadequate set of ideas concerning how wings operate. “Flight Theory,” as usually taught, was too complicated and abstract to be useful in the cockpit, and hangar lore was usually wrong. Langewiesche felt that if pilots had a better, more functional understanding, they’d have fewer tendencies to do the wrong thing. He goes on to say this: “Flying is done largely with one’s imagination! If one’s images of the airplane are correct, one’s behavior in the airplane will quite naturally and effortlessly also be correct.”

I’m not sure we can swallow that whole, but I like the notion that flying is done largely with the imagination—with that synthesizing facility in your brain that allows you to conceive of flight as a set of interactions between elements not always directly visible. Langewiesche describes airplanes in terms of the interactions between basic tendencies—for instance, an airplane wants to fly at an airspeed corresponding to its trimmed angle of attack; it wants to point its nose into the wind; if it’s not pointing its nose into the wind it wants to roll; if it starts to roll it wants to stop rolling, unless its angle of attack gets too high, in which case maybe trouble; etc. Although Langewiesche’s descriptions of aircraft dynamics are often incomplete and over-simplified (he treats wings as if they were merely inclined planes and inexcusably blows Bernoulli off as unhelpful for understanding flight), he was certainly among the first to describe flight in a manner expressly intended to help a pilot develop the integrative “imagination” necessary to fly safely—and well.

There are few illustrations in Stick and Rudder. Langewiesche’s expository prose is so on the mark that it doesn’t require much backup. But when rereading Stick and Rudder I was struck by the drawing on page 213, showing two airplanes diving vertically toward the ground. One is going 200 mph, the other 100 mph. They both start to pull out at the same height and pull the same g load. Of course, the one going 200 mph at the start crashes in an emphatic explosion of graphic dots and dashes, while the one going 100 mph recovers with plenty of room to spare. Langewiesche explains that the altitude necessary to recover an airplane from a dive at a given g varies with the square of the (true) airspeed. Start the recovery going twice as fast and you’ll need four times the altitude if your technique is the same.

This struck me because earlier in the day I had done a masterfully incoherent job of describing just that simple relationship. Maneuvering flight has several relationships in which something interesting varies with the square of something else, or with the square root. Stall speed varies with the square root of the load factor. For a given load factor, or g, the radius of a turn varies with the square of velocity. Doesn’t matter if the turn is in the horizontal or vertical plane, or somewhere in-between. A little extra airspeed can mean a lot of extra airspace required—which is, according to Langewiesche, “a point of practical interest for the poor suckers who dive on girls’ houses.”

It’s true. Love is a perilous thing, and the laws of physics don’t help. This is, don’t forget, the month of Valentines. Better to send a Valentine than to buzz the chimney.