Technicalities: Bookends

The other book was sent to me as a friendly gift by its author, who certainly never imagined that I would write something about it. His name is Dan Raymer. He is somewhat of an authority on airplane design, having written a compendious yet surprisingly readable introduction to the subject called Aircraft Design: A Conceptual Approach, and having had an illustrious career as a configuration specialist for Rockwell, Lockheed and RAND. The book he sent me, Living in the Future, is his personal and professional autobiography, up to now — he is 56 and will probably assemble enough material for a sequel before his tank runs dry.

Living in the Future is self-published, and the book itself exhibits some of its author's quirky, out-of-the-box design sense. The first half is an anecdote-laden personal narrative in which Raymer caroms back and forth, like LeBron James, between first and third person, the second a generously illustrated account of designs and projects that Raymer created or participated in. The 550-page volume has two front covers, one of which admits, by the notation "Chapters 12-27," that it is really the back cover, or middle cover, or whatever you call the starting point of the middle of a book whose two halves are upside down and backwards with respect to one another. Third and fourth covers are sandwiched in the center. I guess this is what you get when there is no one to rein in a writer. The effect of this cover-intensive arrangement is that I never know, when I pick up the book and open it at random, what I am going to find. The book is a big buffet of all kinds of stuff — including ample evidence of how strange we all looked in the 1970s — and if you don't like what you find in one place, you can look in another.

It provides a close-up of the human lives inside the gigantic and impersonal-seeming Rockwells and Lockheeds of this world. Raymer has seen his share of the Dilbert side of aeronautical engineering, including bosses with fixed ideas, impenetrable fiefdoms and contracts let through under-the-table deals. He has also worked on an array of fantastic designs, and you get the sense that what accounted for his precocious success, apart from sheer ability, was a complete lack of preconceptions about how an airplane ought to look.

It was Dan Raymer's good fortune to launch his career at a time when electronic control systems were beginning to liberate designers from the old constraints of basic aerodynamics. In one passage, he describes receiving the news that the thin wings of his brilliant design for an F-16 replacement were so flexible that at high speeds the effect of the ailerons was reversed. Making them stiffer would have entailed an unacceptable weight penalty. This phenomenon was not unknown; it is a potential pitfall for all fast airplanes that have long, flexible wings, including airliners, and is commonly dealt with by reverting to inboard spoilers for roll control at high speed. Dismayed at first, Raymer quickly hit upon an out: Just program the fly-by-wire control system to reverse the roll commands above some critical speed. The pilot would never know the difference. Such is the devil-may-care atmosphere in which modern fighters are made.

It was not always so. Half a century ago, when Stick and Rudder was in its first printing, airplanes had to behave themselves without artificial aids. Perhaps that's why most of them looked pretty much alike. And because flight came naturally to them, one could describe a finite universe of flight phenomena and pilot actions and the sensations that accompanied them.

That is what Wolfgang Langewiesche's book did. In 1944 he could write, "Because the ship wants to do the right thing and resists doing the wrong thing, the pilot is always being guided by his airplane's feel." This was the last thing you could have said about Raymer's exotic creations — none of which, by the way, as he himself points out, ever flew.

Much of Langewiesche's language sounds quaint today, and some of it is downright bizarre. Objecting, for example, to the word elevator on the grounds that it implies control of altitude, whereas it is really the throttle that controls altitude, he chooses to call the pitch control "flippers." He calls the speed ranges of an airplane its "gaits," borrowing a metaphor from a mode of transportation remote from modern experience, and speaks of reserve lift as "buoyancy." In one respect, however, his language is timeless. Throughout the book runs, like a vast and stately subterranean river, the concept of angle of attack. An airplane is not a chariot adorned with wings; it is a wing to which a sort of sleek howdah has been attached. The very first chapter, significantly, is entitled not "How an Airplane Flies" but "How a Wing Is Flown."

He assumes — or attempts to create — a pilot highly attuned to his airplane's interactions with the air. Here is a passage chosen at random; Langewiesche is discussing the left-turning effect owing to the rotational — or more properly tangential — component of the slipstream:

"You would expect the airplane to show a very pronounced left-turning tendency while approaching a power stall. It does. But when the 'break' of the stall has occurred, the left-turning tendency temporarily disappears in some airplanes even though the engine is still wide open, and the ship is still slowed up, and the pilot expects to have to hold much right rudder. This puzzles many pilots."

I would wager that not one in a hundred pilots today has observed this phenomenon, let alone been puzzled by it. Observing it would require flying the airplane deep into the stall and holding it there under full power; and being puzzled would require having a clear conception of flow conditions in the stall as well as a lively sense of when the airplane is slipping or skidding.

The airplanes in which people learned to fly in Langewiesche's era — before, during and shortly after World War II — were mostly taildraggers with wing loadings of 10 pounds per square foot. They were uninsulated and unsoundproofed — at one point he complains about the difficulty of teaching in such a noisy environment — and not very powerful. Being light, they were highly responsive to random air movements and to conditions of flow over their wings and tails. If you botched a maneuver and lost control of them, on the other hand, they would fall back into controlled flight, or into a docile spin, as big model airplanes would.

Whereas a modern flight student learns to watch the airspeed indicator and the ball and to be alert for the stall warning horn, the student of Langewiesche's era was encouraged to rely on more direct sensory inputs: the sound of the air, the rumble of the impending stall, the subtle sensation of leaning that came from even slightly uncoordinated flight. Flying was a sensory experience, like sailing a small boat. Langewiesche assumes this; most of his book is devoted not to "techniques" as a modern book would be, but to explaining how maneuvers ought to feel, and why they feel the way they do.

Most airplanes — ultralights and some LSAs excepted — don't feel that way anymore. In fact, a pilot's skills increasingly involve managing airplanes rather than flying them. Flying jets — the pinnacle to which every young pilot aspires — amounts, most of the time, to being a button-pushing surrogate for ATC.

I do not mean to say that this is a terrible thing. Our tools evolve. I can go far with a car but am at a loss with a hoss. It's just interesting to see how, in a single pilot's lifetime, Langewiesche's once-indispensable classic has become a queer relic, written in an unfamiliar language and evoking experiences that most of us will never have.

But for someone who aspires to being a pilot in the original sense of the word, it is still very much worth reading.

A Correction
A couple of months ago, in a column about extremely big airplanes, I said that although a solid object gains weight in proportion to the cube of its linear dimensions, a hollow shell, like an airplane, gains weight, and surface area, in proportion to their square. A reader, C.L. Landers, formerly director of helicopter design at McDonnell Douglas, pointed out that this would be true only if the sizes of structural components such as skins and stringers did not increase. He's right; bigger airplanes, of course, have more massive structural components than small ones do. I should have thrown in some weasel words like "not always," because skins, in particular — which make up a large portion of structural weight — tend not to thicken quite in proportion to linear dimensions, but to acquire more and more internal stiffeners instead. In general, however, and particularly in the context of immense airplanes, Mr. Landers is right and I was wrong.