In the year following his historic transatlantic flight to Paris, Charles Lindbergh, flying again in the Spirit of St. Louis, lost his way somewhere between Havana, Cuba, and the southwest coast of Florida. It happened in the middle of the night, and it alarmed Lindbergh enough that years later he recalled the incident in his memoir The Autobiography of Values:
Over the Straits of Florida my magnetic compass rotated without stopping…. I had no notion whether I was flying north, south, east, or west. A few stars directly overhead were dimly visible through haze, but they formed no constellation I could recognize. I started climbing toward the clear sky that had to exist somewhere above me. If I could see Polaris, that northern point of light, I could navigate by it with reasonable accuracy. But haze thickened as my altitude increased….
Nothing on my map of Florida matched the characteristics of the Earth I had seen … where can I be? I extended my water map [a topographic map of the water with coastlines, reefs, shipwrecks and other structures] … I had flown almost at right angles to my course and that … I put almost 3 hundred miles of road !
Had this occurred nine months earlier, over the Atlantic, the name “Lindbergh” might today be no more than a forgotten bit of aviation trivia. His nearly tragic Caribbean trip, however, turned out to be a critical moment in time, not only for Lindbergh’s understanding of navigation, but also for the advancement of the practice for all aviators. A few months later, the newly famous pilot would meet a young Naval officer, and their collaboration would change the world of flying.
It would possibly be difficult for Lindbergh to only learn to sail the year after his nonstop flight from New York to Paris, however, in 1927, the practice was even more an art than a science. Airmen had tried to cross the Atlantic with varying degrees of good fortune since 1919, but they still used equipment and strategies designed for navigation, which proved incorrect to the sky.
When Naval Commander John Rodgers attempted the first flight from California to Hawaii in 1925, the expedition ended disastrously, illustrating how unreliable the aircraft can be. Although they wore sextants, the Rodgers team did not rely on the observations they made from their PN-9 seaplane. Instead, they relied on radio navigation, locating their recovery by determining the direction of signals transmitted through aid vessels along the route. But the generation of these ship-based radiogoniometers was still poor and, combined with an operator error, led the PN-9 to lose a source ship. Without fuel, the plane was forced to land in the ocean thousands of miles from Hawaii. The team spent 10 brave days sailing their flying boat to the Hawaiian island of Kauai, in what was perhaps the greatest maritime feat ever performed through the airmen.
By the end of World War I, some pilots were using bubble sextants, which in flight substituted an artificial horizon for the actual horizon on which mariners depended, as well as radio navigation, but Lindbergh decided that for his Paris flight, the devices were both cumbersome and ineffective. The Spirit’s high wing obstructed his view of the sky, making star sightings nearly impossible. Even if he’d had a clear view, it would have been too big of a challenge trying to take sextant measurements with one hand while controlling the unstable Spirit with the other, then scribbling calculations that took a trained mariner 15 minutes, all done by a single pilot forgoing sleep on a 33-hour flight. Radio navigation, the method that sent John Rodgers sailing to Hawaii, was clearly unreliable and the equipment was heavy.
Instead, Lindbergh felt that the payload of his most productive aircraft is used for additional fuel that can be fed to the right rate any significant deviation from the flight plan once it hits ground; Western Europe Array after all, a great goal. It was fully founded in esteem, calculating its position from one point to another following its speed. He used a clock and compass as he had done between the checkpoints across the flight.
Despite all the obstacles, Lindbergh still made landfall in Ireland less than 3 miles from his planned site, an ordinary feat. Did you have any kind of superhuman sense of direction? His ability to maintain a course in exhaustion is an undeniable achievement, however, the National Aeronautical Association flight observer, John Heinmuller, also noted that the distribution of tension over the Atlantic the two days of flight was such that the net wind drift was 0 – “the first time rare weather situations were recorded through weather experts”
The magnitude of Lindbergh’s achievements has led many others to make transoceanic air navigation just a matter of determination. At least 15 other people died in an attempt to cross the ocean for the remainder of 1927, prompting calls for federal regulation. Although inexperience played a role in many of these accidents, the insufficient navigation generation had left almost everyone, causing everything, inconvenience to death.
Lindbergh watched anxiously as others tried to make his feat disappear into the sea. After completing his tour of Latin America and the Caribbean with the Spirit of St. Louis in early 1928, he was eager to find better aircraft and procedures for long-haul flights. Although he refused the heavenly navigation to go to Paris, upon returning aboard the USS Memphis, he was fascinated by the ship’s navigator’s ability to fix the position with observations of the sun and stars, and decided to resume the skill, writing, “It was a lot of fun” to photograph the sun”… with the Sextant of Memphis. I was lucky enough to hit him with some precision.
Upon his return, Lindbergh began planning an around-the-world flight, scheduled to kick off a few months later in a Ford Tri-motor provided by Henry Ford and copiloted by his close friend, Thomas Lanphier. That April, he went to observe air operations aboard the USS Langley, where he encountered an enthusiastic Navy Lieutenant Commander, Philip Van Horn Weems, who was conducting navigation experiments for carrier-based aircraft. Weems demonstrated several of his innovations to Lindbergh, including a bubble sextant that he was helping the National Bureau of Standards to improve, and his prototype Second-Setting Watch: the first true aviator “hack” watch that could be set precisely to the second. (Later, the military realized a major benefit of this precision, and began to synchronize multiple watches for field operations, thus making famous the line “Gentleman, synchronize your watches.”)
Several weeks later, after donating the Spirit to the Smithsonian Institution, Lindbergh decided he would set out from Washington for Detroit to finalize his plans with Ford and Lanphier. He felt the trip would be an ideal time to learn “avigation”—a popular term used in the 1920s and ’30s to differentiate air navigation from maritime practice—and asked polar explorer Lincoln Ellsworth for suitable tutors. Ellsworth recommended Weems.
Shortly after Roald Amundsen’s Arctic flight in 1925, which the team nearly lost after a crisis landing, Ellsworth began searching for seriously better air navigation techniques. At the time, Weems was an instructor at the Annapolis Naval Academy, and although he was not a pilot, he discovered that the challenge of using celestial navigation on aircraft was an attractive, high-level challenge. His conservative military superiors disagreed and rejected his request for investment to expand a simplified system. However, Weems’ concepts inspired Ellsworth so much that he helped fund the research.
Lindbergh petitioned the White House for Weems to be assigned as navigation tutor, and the Navy officer received a leave of absence, to the irritation of his superiors. He told Lindbergh later, “My relations with the Navy Department [have] been rather peculiar. I get patted on the back by one crowd and kicked in the pants by another!”
Not surprisingly, most Americans assumed Lindbergh was an expert in all things aeronautic, and learning that he needed training in navigation left many reporters confused. When Lindbergh began his training with Weems, the New York Times wrote, “It will be news to…millions that Colonel Lindbergh needs to be taught navigation…. If the Colonel doesn’t know how to navigate, who knows anything about anything?” But the publicity started a conversation in the aviation community, one thoroughly documented by the newspapers of the time, about the poor state of air navigation and the potential for celestial navigation to be a solution on long over-water flights.
Weems approached Lindbergh’s training with items from his bag of tricks, including his hack watch. Previous chronometers could be set only to the minute; this was an acceptable error for 19th century mariners who might go weeks or more before stopping and making an adjustment, but not for 20th century pilots who could use radio broadcasts to synchronize their timepieces. A watch error of 30 seconds could throw off a position calculation as much as seven miles, so Weems’ innovation was significant.
Weems used most of the lessons to teach Lindbergh how to find his position by shooting the sun with a very rare sextant. It was a 1924 Bausch & Lomb model, of which only six were made, and Weems believed it was still the best model available in the United States. Bubble sextants had been around for more than a decade, but because so little attention had been paid to aerial navigation, their design had not advanced much. During his sessions with Lindbergh, Weems carefully studied the sextant’s deficiencies, later taking his notes to the National Bureau of Standards, which worked with Bausch & Lomb to produce an improved version that saw wide service in the 1930s.
Another Weems innovation used in Lindbergh’s education was the star’s altitude curves, a revolutionary set of maps that allow a browser to locate its position using two stars (one era the northern star, Polaris). The graphs reduced the calculation time from 15 minutes to 40 seconds. During the day, instead of triangular the position with two stars, a browser can use the sun for a position line. By measuring the angle between the horizon and the location of the sun in its daily trajectory, a browser can simply draw a line on the balloon and be sure that its position was a point somewhere on that line.
In line position, Weems published Cliffs’ latest notes for this more complicated calculation. Although Lindbergh dropped out of school to fly, he turned out to be a perfect student and “worked joyfully for days on impressive math,” Weems said in a letter to a friend. “Lindbergh is a fair student. He [studies] until noon or an hour and is not “agitated” or haste.” During a stopover in New York, Weems stayed with Lindbergh to spend more time training personal lessons, but discovered that he “didn’t do much training”; the pilot “was brilliantly and temporarily understood. Learned.
Weems and Lindbergh took a series of flights together in May 1928 in a Ryan Brougham given to the pilot by Benjamin Franklin Mahoney, owner of Ryan Airlines (the San Diego company that built the Spirit). The first flight was from Bolling Field in Washington, D.C., to Long Island’s Curtiss Field. Even with Weems’ innovations, celestially navigating while flying was a two-person job. Weems did the calculations, though he noted, “Lindbergh flew his ship with one hand and took a sextant altitude of the sun with the other! I am confident that this was the first time in history such a thing had ever been done.” But Weems’ system was still a work in progress: He noted that Lindbergh’s accuracy in this walking-and-chewing-gum mode could be off by as much as 15 or 20 miles. Shooting the sun next to the pilot, however, Weems was eventually able to fix position to an accuracy of three miles—a margin of error unacceptable today, but the position was certainly good enough to put a pilot within sight of an island.
After stopping in New York, the pair headed to Detroit to meet Henry Ford. Although Lindbergh never made the around-the-world flight, his lessons were not in vain. He helped establish cross-country air routes for Transcontinental Air Transport (known as the “Lindbergh Line” and later as TWA), and was also courted by Juan Trippe of Pan American Airways to establish transatlantic air routes. Because the continental United States was covered by a network of radio beacons, celestial navigation had little application there, but the method became essential for the overseas routes that Trippe was eyeing.
Lindbergh was a remarkably good sport about the publicity over his shortfall in navigational knowledge, and was willing to have Weems draw attention to it—even allowing his Paris navigation to be described as “little more than the automobile tourist” following street signs. The press coverage of Lindbergh’s lessons, along with his ringing endorsement, allowed Weems to launch an aerial navigation consulting business while he was still serving at sea aboard a Navy oiler. The two men kept up a close exchange on navigational questions over the next decade, including collaborating on a variant of the Second-Setting watch, which converted time to arc, the 360 units in which the globe is marked. The improved Lindbergh Hour Angle watch, as it was marketed, helped speed up one of the many calculations with which a navigator was tasked.
With Lindbergh as his first disciple, Weems’ navigation formula temporarily attracted a wide variety of airmen eager to receive information on newer techniques. Armed with a set of tools, adding the bubble sextant, the time to set up the celestial tracking bureaucracy to perform calculations from star altitude curves and position line books (and in the mid-1930s, an aerial almanac, moon ephemeral ephemeris for aviators and a Mark II tracker, which each and every student pilot still receive today) Array the Weems scholars now had everything you need to locate your position in flight. One of the first consumers was Australian navigator Harold Gatty, whom Weems temporarily hired as a leading instructor at his new school in San Diego, California, the first committed to air navigation. The two have collaborated on many advances in navigation, adding the Gatty drift meter, used to measure the drift of an aircraft from a runway. Gatty taught Anne Morrow Lindbergh the Weems formula. When Charles Lindbergh accepted Trippe’s offer and began making overseas inspection flight plans for Pan American at a Lockheed Sirius, he learned that his wife Anne deserved help with sailing. Gatty turned out to be a fair instructor. Lindbergh wrote to Weems that “we used one of its sextants and much of its navigation formula in our last transcontinental [April 1930]. Ms. Lindbergh took all the readings of sextants in addition to executing them and doing maximum navigation.
These flights were textbook examples of the Weems System. In fact, Weems became the Lindberghs’ official chronicler for the 1933 airline survey flight and used it as a case study for his Air Navigation textbook. In stark contrast to what happened on the Paris flight six years earlier, on the survey flight, the Lindberghs, carrying nearly the full suite of Weems navigation products, were able, almost without exception, to find their position.
Lindbergh and Gatty spread the Weems System through much of the aviation community in the United States and elsewhere. Gatty persuaded Lindbergh to bring Pan Am on as a client for the Weems System. The military services lacked enough instructors to train cadets for World War II, so Pan Am’s school served as a leading source of navigators for the Army Air Forces and Royal Air Force at the start of the war. In 1932, Gatty became chief navigation advisor to the Army Air Corps Frontier Defense Research Unit, which developed the service’s first viable navigation techniques for long-range strategic bombers. (One of Gatty’s first students was the architect of air power and later chief of staff of the U.S. Air Force, Curtis LeMay.) American Airlines and TWA also adopted the Weems System in the late 1930s as they began considering transatlantic routes. About the only entity not heavily influenced by Weems was his own branch of the service, the Navy. Focused on carrier-based aviation, in which celestial navigation was of little value, the service largely ignored the needs of its long-range patrol squadrons until the late 1930s, when it had to race to catch up.
For many decades, the Weems System was the principal means of fixing position in over-water navigation for the U.S. military and airlines, along with many of the famed record setters and endurance fliers. In 1937, the astounding transpolar flights that the Soviet Union achieved in Tupolev ANT-25s were made by aviators who were using the Weems System; U.S. observers noted that the Soviet aircraft had a hand-copied version of Weems’ Star Altitude Curves on board.
Lindbergh’s exercise also served as a style for many aviation celebrities who were looking for Weems on non-public orders and advice, adding Richard Byrd, Howard Hughes and Amy Johnson, the pioneer of the British aviator at the time. Weems tried to get Amelia Earhart to exercise several months before the departure for her unfortunate worldwide flight with Fred Noonan, who, as Master Navigator of Pan Am, had been one of the first students. Earhart’s husband, G.P. Putnam refused, noting that she was too busy.
Weems continued to be fascinated by navigational problems throughout his life. He collaborated with Ed Link to develop the Celestial Navigation Trainer, part flight simulator and part planetarium, which trained many World War II navigators. Awed, like the rest of the world, by Sputnik and the dawn of the Space Age, he began to adapt his aerial navigation techniques for the unique challenges of orbital mechanics; the adaptations were put to use in the Apollo program. Weems also founded the Institute of Navigation, which is still the leading professional society devoted to the advancement of navigation.
The mariner whose navigation pursuits started out as an annoyance to his superiors spent the rest of his career changing the way pilots fly around the world and in space. Weems created a community of aerial navigation experts and practitioners where none had existed. And if Lindbergh hadn’t been a good enough pupil to absorb Weems’ new techniques and a humble enough man to let his experience serve as an example to other aviators, professional standards of aerial navigation would have taken longer to develop, with a cost in lives lost and flights unmade.
Roger Connor is co-curating the National Air and Space Museum’s Time and Navigation exhibit.
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Roger Connor is a curator in the Aeronautics department at the National Air and Space Museum.