Photo By Raymond Boyd/Michael Ochs Archives/Getty Images

A Pilot Explains Waypoints, the Hidden Geography of the Sky

In an excerpt from his new book, Skyfaring: A Journey with a Pilot, author Mark Vanhoenacker explains how airliners navigate the skies through a series of evocatively named waypoints connecting the globe.

An airplane navigates through the sky along a route composed of beacons and waypoints. Waypoints are defined by geographic coordinates or their bearing and distance from a beacon, and by a name, which typically takes the form of a five-letter capitalized word—EVUKI, JETSA, SABER. The idea is that they will be pronounceable and distinct to controllers and pilots regardless of their first language. The pilot’s map of the world, and the flight computers’ too, is atomized into these waypoints. They are the smallest nuggets of aerial geography, and in some sense the only such unit that matters once you leave the runway. They are the sky’s audible currency of place.

From a plane, even a wide modern road can look as slow and old-fashioned as an ancient bridleway. The plane slides like an eye over the page, like a finger across a map, over everything the road and the drivers on it must turn to avoid—towns, mountains, lakes—features so low they appear nearly smooth from above. Waypoints, though invisible, remind us that while pilots are not nearly as constrained by the sky as drivers are by roads, neither is our path always as free as it appears.

That is not to say that a waypoint is a place like any other. Though they are often strung together in airways, we’re frequently allowed to move between two distant waypoints without overflying those that lie between; as if a driver could leave the road to tunnel directly through hills and forests before meeting it again, further along. And a waypoint, for all its extraordinary specificity, is not a single place at all. It exists at all altitudes at once. It is possible for many planes to cross the same waypoint at the same time, at different altitudes, yet each plane’s navigation computers show it at the same position. A waypoint is like the address of a skyscraper that does not specify the floor. The speed of a cruising airplane also means that we often do not get anywhere near a waypoint that is on our flight plan, because we must turn well before the waypoint if we are not to overshoot the route on the other side of it. For a sharp turn, in a strong tailwind, we may begin to turn 5 miles before the waypoint, something to imagine, that in a car you would start to turn the wheel so far before the intersection.

There is a rhythm to waypoints, which roughly matches the rhythm of the human geography below. Tourists from North America wandering the cities of Western Europe may have the sense that historically significant places occur every few dozen yards; in the sky over Europe we may cross a waypoint every minute. In contrast, over open sea, or a place such as northern Canada, we may fly forty-five minutes or more, hundreds and hundreds of miles, between waypoints. The pace of passing waypoints also roughly echoes the workload in the cockpit. Most of the waypoints crossed will come in the first and last minutes of a flight, when the plane must make many turns to move between a runway and its route, and then back again at the far end.

Pilots come to know many individual named points on the routes they fly most often. Some, such as those that are well-known entry and exit points for Atlantic Ocean crossings, feel like doors, almost, or gates—when I think of LIMRI or MALOT, off Ireland, I think of the phase of flight in which they occur, the start or the end of an oceanic crossing. The feeling is comparable to the name of a bridge that you only cross when leaving or entering a city, one to which newscasters will casually refer when talking about traffic, and you know they are speaking to those who are leaving town or planning their return.

The names of many waypoints are random; an example of that early lesson taught in linguistics that there are many more possible words—spellable, pronounceable—than there are actual words. There is an automated tool available to airspace planners that generates just such names and helps ensure that identical names are not geographically close. Many other names, however, are not random. In these we see perhaps the last realm on earth in which meaningful place names are scattered over a geography that is new to the namers, a world that is new, in this case, to everyone.

Many names in the new geography of the sky reflect aviation’s nautical heritage and the water below them. Near Perth, Australia, are the waypoints FLEET, ANCOR, BRIGG, SAILS, KEELS, WAVES. South of Newfoundland, in the vicinity of the historic Grand Banks fishing grounds, is the waypoint BANCS; further north along the Canadian coast lie SCROD and PRAWN. Sometimes there are multiple waypoints with the same name, and when we type one into a flight computer, it will ask us which of these homonymous, far-scattered places we mean to navigate toward. There are five SHARK waypoints—one east of Sydney, the others off the islands of Jersey, Maui, Taiwan, and Trinidad.

Near the Isle of Man is KELLY, in reference to an old music-hall song called “Kelly from the Isle of Man.” Off England’s Channel coast are DRAKE—for Sir Francis—and HARDY—for Sir Thomas, the old friend to whom Lord Nelson, as he lay dying on the deck of his flagship, was heard to say: “Kiss me, Hardy,” and “God bless you, Hardy.” On sky maps of the Tasman Sea, the triangles that denote the waypoints hanging like notes on a musical staff arcing toward New Zealand are marked WALTZ, INGMA, and TILDA—a reference to Australia’s unofficial anthem, “Waltzing Matilda”—while many thousands of miles west, running north to south over hundreds of miles of Indian Ocean off Western Australia, is a lyrical sequence that begins WONSA, JOLLY, SWAGY, CAMBS, BUIYA, BYLLA, and BONGS—“Once a jolly swagman camped by a billabong . . .”

Continental Europe has fewer locally themed waypoints, or at least fewer that are apparent to an English speaker, though off the Dutch coast floats TULIP, and it’s easy to speculate about SASKI—Rembrandt’s wife was Saskia. Over Germany, an English speaker might hear ROTEN as a meaningless, albeit pronounceable word; a German pilot might hear the bells of the medieval town of Rothenburg ob der Tauber. Crossing the border between Austria and Germany are a series of waypoint names that form awkward phrases. NIGEB—DENED—IRBIR is a loose variation on the German Nie gebt denen ihr Bier: “Don’t ever give them [the pilots?] their beer.” In the heavens near Stuttgart are VATER and UNSER, “Our Father” (“who art in heaven,” as the Lord’s Prayer continues). Northeast of Nuremberg, near the German–Czech border, are ARMUT, “poverty,” and VEMUT, Wehmut, German’s fine old word for “wistfulness.”

Near the border of India and Pakistan is the waypoint TIGER. Another TIGER forms part of an arrival pattern for London, as if lifted from Britain’s former empire as incongruously as an animal taken from a warm place to a zoo in a cold city. On flights from Singapore to London I may overfly both TIGERs in the same night.

America’s sky-mappers have gone to more trouble than most to ensure that local colors fly in the country’s skies. The Sonoma County airport in California is named after Charles M. Schulz; nearby is the waypoint SNUPY. Near Kansas City are the culinary waypoints BARBQ, SPICY, SMOKE, RIBBS, and BRSKT. Near Detroit is PISTN, surely for the basketball team whose name reflects the city’s heritage of industry; the skies around Detroit also feature MOTWN and WONDR (Stevie, Michigan-born) and EMINN, perhaps for the rap star. Houston’s nearby SSLAM is followed a few miles beyond by DUUNK (not to be confused with DUNKK, near Boston, a reference perhaps to a certain Massachusetts-born doughnut chain). The skies around Houston also feature ROKIT for the city’s space legacy, and TQELA, WORUM, CRVZA (beer), CARNE (meat), and QUESO (cheese) for the city’s cross-border culinary traditions that arriving passengers may soon be enjoying.

Boston has lifted a particularly intricate constellation of itself into the ether above New England. There is PLGRM, for the region’s history; CHWDH, LBSTA, and CLAWW for its food; GLOWB and HRALD cover the city’s newspapers; while SSOXS, FENWY, BAWLL, and OUTTT chronicle the anguishes of the city’s baseball team across the heavens. Even the region’s speech—WIKID, followed by PAHTI—seems to be mapped. There’s a NIMOY waypoint; Leonard was born in Boston. LYHTT floats above the harbor island on which stands Boston Light, the 1783 replacement of the 1716 beacon that a twelve-year-old Benjamin Franklin memorialized in a ballad. Passengers may cross the LYHTT waypoint and see this lighthouse, the first in what would become the United States and the only one that retains a lighthouse keeper, as they descend to the city it marks.

St. Louis has the nearby waypoints ANNII and LENXX, for reasons that aviation authorities could not explain to me; perhaps it’s only that an air-traffic controller there was a Eurythmics fan. The origins of other waypoints near St. Louis—AARCH, for example, a reference to the city’s skyscraping Gateway Arch—are less obscure. Mark Twain died seven years after the first flight at Kitty Hawk. The riverboat pilot himself never flew. But Tom Sawyer Abroad features a “noble big balloon” equipped with “wings and fans and all sorts of things,” and in an 1869 letter Twain wrote that “the grand problem of aerial navigation” is “a subject that is bound to stir the pulses of any man”—reasons enough to think he might be pleased by the thought of the sky place TWAIN, above Hannibal, his childhood home on the Mississippi.