Originally published in the American Aviation Historical Society Journal (http://www.aahs-online.org) and reprinted with permission. Text copyright ©2005 Nick T. Spark. Unless otherwise mentioned, all photos copyright ©
by the estate of Donald A. Hall, Sr. and used with permission.

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INTRODUCTION:

Click to enlarge Ryan Airlines owner B.F. Mahoney, Charles A. Lindbergh and Donald A. Hall (l-r) pose in front of the newly-completed Spirit of St. Louis at Dutch Flats in late April 1927. Lindy's stature usually dwarfed his companions; in a few short weeks so would his celebrity. In the wake of his epic flight, he became the most famous man on Earth. Hall and Mahoney, however, would remain largely unheralded.

In 1998, a letter arrived at the home of Don Hall, Jr. from Ev Cassagneres, an amateur historian and author of numerous books about Ryan aircraft. "Are you," the letter began, "the son of Donald Hall, designer of Charles Lindbergh's Spirit of St. Louis?" The answer, which was in the affirmative, came as a shock to Don's young son Nova. He knew almost nothing about his grandfather, who died in 1968, several years before he was born. Now he was being told that one of his relatives had not only known Lindbergh, but that he'd been involved in one of the most important feats in aviation history. It seemed incredible.

A short time later Cassagneres visited the Halls at their home in Sedona, Arizona. Unfortunately, their time together proved frustrating. Impaired by a stroke, Don Jr.'s memory of his father proved sketchy, and while Cassagneres could provide details of Donald Hall Sr.'s work with Lindy, he did not know the full story. "I know from interviewing Charles Lindbergh that your grandfather was one of the key figures in the design and construction of that plane," Cassagneres told Nova. "But I hope to learn more." The more they talked, however, the more obvious it became that barring the discovery of some forgotten book of memories, the legacy of Donald Hall Sr. had been lost forever.

A little less than a year later, fate stepped in. While moving boxes in the garage, Nova discovered two sealed trunks. With the aid of a crowbar, he popped them open. The first contained only tools. The second however contained a lost treasure trove of photographs, motion picture films, logs, blueprints and mementos related to Donald Hall's work on the Spirit. By a quirk of fate, Nova had not only found something of historical importance, but something personally significant as well. The photos and other documents provide a glimpse into the life of Donald Hall, and a view into the feverish months of work that produced the Spirit of St. Louis, and a legend. It's a well-known story worth another look…

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In 1926 Donald Hall took a leave of absence from his position as an aeronautical engineer at Douglas to become an Air Corps cadet. Hall completed the course but failed to get his wings. Ironically Hall's flight handbook bore the signature of a previous student - none other than C.A. Lindbergh. Later the two would meet face to face and share a laugh over the coincidence.

Chance and coincidence - of such things history is made. Charles A. Lindbergh's first choice of airplane for an attempt at the non-stop New York to Paris flight, and the Orteig Prize that went to those who first accomplished it, was a Wright-powered Bellanca monoplane whose passenger compartment could be modified to accommodate a large fuel tank. Giuseppe Bellanca himself arranged for Lindbergh to meet with Charles Levine, the millionaire chairman of Columbia Aircraft in February 1927. Levine had the ideal aircraft, but wanted $25,000 for it - $10,000 more than Lindbergh's backers had secured. When Levine proposed that he absorb the difference in exchange for a share of the venture, Lindbergh's hopes were momentarily buoyed, and then dashed. As part of the deal, Levine demanded that he choose the pilot. For Lindbergh that was not an option. He hadn't come this far, developing his dream and assembling backers for a trans-Atlantic attempt, only to hand someone else the controls.¹

About the same time that C.A.L. met with Levine, Donald Hall, a 28-year-old aeronautical engineer and graduate of the Pratt Institute, left his job at Douglas Company in Santa Monica to join San Diego-based Ryan Airlines. Ryan, a small concern which produced two highly successful monoplanes known as the M-1 and M-2, seemed a good fit for young Hall. He'd been freelancing there off and on. Now owner B.H. Mahoney, who had recently acquired sole ownership of the company from founder Claude Ryan, was in the process of building a new 42' wing model to be known as the B-1 "Brougham". He wanted Hall on his staff to work on it full time.

Click to enlarge The Ryan Airlines factory, photographed sometime after 1927 - the small plaque visible in front of the building commemorates the New York to Paris flight. A small company with a fair reputation, Ryan was certainly not Lindbergh's first choice. None of the other companies he approached however, were prepared to risk their reputation on the brash, young, Air Mail pilot. Where others smelled danger however, T. Claude Ryan and B.F. Mahoney smelled business opportunity.

After just a few days of work however, Donald Hall was pulled off the B-1. A telegram had arrived at Ryan from Lindbergh's St. Louis backers: "CAN YOU CONSTRUCT A WHIRLWIND ENGINE PLANE CAPABLE OF FLYING NON-STOP BETWEEN NEW YORK AND PARIS. IF SO PLEASE STATE COST AND DELIVERY DATE." The proposition itself must have thrilled Hall, and at the same time caused him some unease. Years later he admitted to feeling "a little doubtful" that such a plane could actually be built. After consulting with Claude Ryan, who although no longer a partner in the company had stayed on as general manager, Hall drew up some specifications. Shortly thereafter a reply was sent via Western Union: "CAN BUILD PLANE SIMILAR TO M-1 BUT LARGER WINGS CAPABLE OF MAKING FLIGHT. COST ABOUT SIX THOUSAND DOLLARS WITHOUT MOTOR. DELIVERY ABOUT THREE MONTHS."

That terse telegram would not have sealed the deal for the Spirit had not a host of other companies, including Travel Air, Alexander and Fokker, rejected Lindbergh's inquiry outright. Even if their planes were up for the challenge, and they almost certainly were, the idea of risking corporate reputations on such a venture with a more-or-less unknown pilot must have given them pause. When the dust settled, Ryan Airlines' proposal was not the only practical one, but the only one period. So after a further exchange of telegrams discussing the practicability of the undertaking and the assembly timeframe -- the staff at Ryan agreed to Lindy's requirement that the aircraft be finished in two months instead of three - Lindy set off for San Diego.

C.A.L. arrived on February 24th, and two days later having met with B.F. Mahoney concerning the financial details and with Donald Hall concerning the technical ones, signed a contract. Equipped with a Wright engine, the plane would cost $10,580. The price might have been higher but Mahoney, sensing an opportunity to make a name for his company, decided to throw in additional equipment at cost. Even with this incentive, and even though he was a man who no longer had other viable options, Lindbergh must have signed the contract with mixed emotions. The Ryan factory itself consisted of a single run-down building far removed from the nearest airstrip. It had served as a fish cannery and therefore did not exactly look or especially smell like success. Yet Lindbergh rationalized his decision, and perhaps even came to regard Ryan's peculiarities as assets. As Scott Berg wrote in his Pulitzer Prize-winning biography Lindbergh, in the end "it all smelled right - an industrious, no frills operation" that just might be able to deliver what they claimed.

Click to enlarge The wing and fuselage of the first B-1 "Brougham", a successor to Ryan Airlines' successful M-1 and M-2 monoplanes, were nearly complete by the time work commenced on the New York to Paris plane. The B-1 (pictured) wouldn't fly until after the Spirit did. The finished product, like Spirit, sported a Wright engine and Fokker-type landing gear. For decades a debate has simmered regarding whether the B-1's design, or that of another Ryan product, served as a basis for the Spirit, or whether Donald Hall designed a plane from scratch for Lindy's venture. As this 1927 photo demonstrates, the NYP plane and the B-1 clearly had a shared lineage. (Photo Courtesy Ryan Aeronautical Company via Ev Cassagneres)

According to Ev Cassagneres, who met Charles Lindbergh in 1968 and interviewed him several times prior to his death in 1974, what really sold Lindbergh on Ryan was Donald Hall himself. The two were about the same age, and shared a passion for the outdoors, a sense of independence, a belief in hard work and discipline, and a love of flight that had led both to enroll in the Army Air Service cadets at about the same time. As fate would have it, Lindbergh graduated with the class of '25 at Brooks Field, became a pilot, and earned a commission. Hall, despite his best efforts, washed out of Brooks in '26 and ended up flying a drafting table. They apparently got on famously, their partnership being as Cassagneres puts it "a phenomenal complementing of two brains and spirits."

Hall for one must have sensed, from the moment he'd read that fateful telegram, that the task ahead would be extremely difficult. According to his own account, he initially believed that a modified M-1 or M-2 could make the record-setting flight, but as he continued his calculations Hall determined that even a stripped down variant would not fit the bill. When Lindbergh arrived in San Diego, the design specifications were further cast into question. Lindy shocked Hall, and probably everyone else at Ryan, by stating that he intended to fly the Atlantic solo -- he'd never seen fit to mention it in his telegrams! The concept had obvious merits beyond the fact that it would be an absolutely spectacular achievement. Less weight and space meant the plane could carry more fuel. But could anyone stay awake long enough to make such a flight? Hall wondered. How far was it to Paris, and how many hours would it take to get there, anyway? According to Lindbergh's 1953 book Spirit of St. Louis (also incidentally a Pulitzer winner), neither he nor Hall knew precisely. One of the first things they did together therefore was to visit a local library, where they used a piece of string from a grocery package to take measurements off a globe. 3600 miles it turned out, give or take a few, most of it across a trackless ocean. The flight would take about 40 hours. Could Lindbergh actually stay awake and pilot a plane by instrument for nearly two days? He believed he could, and he'd better be right. His very life would depend on it.

What happened in the next few weeks, as the plane that came to be known as the Spirit of St. Louis took shape, has been written about many times, appeared in films and documentaries, and been subject to a great deal of hashing and rehashing by a whole host of historians and writers. While one might therefore imagine that the exact genesis of the Spirit would be a rote topic, some aspects of it remain grey areas, including Donald Hall's exact role. It's not exactly a surprising set of circumstances. For years names other than Hall's were most strongly affiliated with the endeavor. Ironically Claude Ryan, the "man who built the company that built Lindbergh's plane" received a lot of the credit, despite the fact that he had little to do with the SOSL itself. These circumstances have something to do with the focus of the media at the time, with Donald Hall himself - who likely did not want to publicize his own role lest he jeopardize his career at Ryan - and to the fact that a truly detailed discussion of the construction of the plane did not appear until 1953, twenty-six years after the fact. Indeed Charles Lindbergh's book, The Spirit of St. Louis, may have been the first to really discuss Hall's work and attempt to give him his due.

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Don Hall, seen here drafting at his desk, once estimated he spent roughly 86 hours per week working on the SOSL. Due to the two month delivery deadline he and the Ryan crew often worked without blueprints or detailed sketches. It must have made for some frustrating days; fortunately the Ryan staff proved competent. (Right) Hall's original, hasty design for the Spirit's wing, rendered on a piece of cardboard. After the NYP craft reached Paris, Hall created a real set of blueprints which were used to build a replica aircraft for Japanese clients who intended to cross the Pacific.

Ev Cassagneres has no doubt that Hall played an enormous role in the design and construction of the SOSL, and that he essentially designed a plane for Lindbergh from the ground up. Hall's own statements certainly seem to bear that out. In a report he prepared for the National Advisory Committee on Aeronautics (NACA) in July, 1927 concerning the design of the plane Hall wrote that "modification of the M-2 was less practicable than a redesign" and that as a result "the airplane was laid out anew, the fuselage following the standard model approximately in regard to design…The fuselage structure was redesigned…" He also added, "I was all alone during the design except for two nights when the purchasing agent, Walter Locke helped me with weight analysis. From the Ryan M-2 we took the wing ribs and tail surfaces, everything else was different."

Essentially, Hall indicates that he created the plane more or less from scratch, although he admits to using the "standard model" as a basis. Over the years some have argued that this "standard model" might have actually been the B-1, whose original design had been sketched by designer Ed Morrow, or the M-1/M-2 which had been designed by Claude Ryan, his factory engineer W. Hawley Bowlus, and a relative newcomer to the business named John K. Northrop. For the most part, these speculations have gone nowhere due to a lack of evidence. Now however, some in-depth investigations by aircraft restorer and builder Ty Sundstrom, who is leading an effort to construct an exact replica of the SOSL as part of the Historic Flight Project, promise to shed light on the subject. In a forthcoming book, Sundstrom and aviation writer John Underwood present documentary evidence to support their belief that Hall used a pre-existing but lesser-known Ryan Airlines design, the M-3C, as the template for Lindbergh's aircraft. That is a wholly believable concept, Ev Cassagneres admits, especially given the brevity of the plane's eight week production schedule and Hall's limited engineering experience.

Click to enlarge Charles Lindbergh shared Donald Hall's small office on the second floor of the Ryan Airlines factory (note Hall's drawing board in the f/g). While Hall designed the plane, Lindy spent a fair amount of time studying long-range navigation and, slowly but surely, plotted his course.

Yet at the same time this type of scenario conflicts with the accepted course of events as described not just by Hall and also by Lindbergh. In his book Lindy states that he believed the aircraft to be wholly unique, noting that designing the craft from scratch had "great advantages" that more than justified the time spent building it. "Every part of it can be designed for a single purpose," he states, "Every line fashioned to the Paris flight. I can inspect each detail before it's covered with fabric and fairings… By working closely with the engineer, I can build my own experience into the plane's structure and make the utmost use of the theories he expounds." Could it be that the staff at Ryan effectively pulled the wool over Lindbergh's eyes, convincing him his plane was "special" when it was really a modified, pre-existing design? Or could it be that Lindy exaggerated his level of control over the design and construction of the aircraft? Is it possible that, by the time Lindbergh finished his book - a quarter century after the fact - he'd begun to buy into some of the legends surrounding the construction of the plane? These are interesting questions and the facts to answer them are still emerging.

In truth, whether or not Hall designed a plane from scratch or merely modified -- however radically or superficially -- an existing design may not be that important a distinction. His efforts were intense and focused, and the stakes were as high as they come. The new plane had to be capable of a sustained flight farther than anything had yet flown, and of longer duration. Hall, assisted by Lindbergh, Morrow, Bowlus, shop superintendent and wing department chief Bert Tindale and the Ryan staff would attempt to produce an incredibly efficient machine designed for maximum endurance. The resulting aircraft would therefore be rather unique in history, constructed not as a commercial product or as the prototype for a new line of aircraft, but for the grasping of one very distant brass ring.

Click to enlarge The steel frame of the NYP plane takes shape. Even at this early stage of construction several off-the-shelf components, including rudder pedals, the control stick and trim adjustment lever have been added to the cockpit. The decrepit state of the Ryan Airlines factory is apparent - note the shattered transom windows visible behind and above the tail!

According to Hall's report, Lindbergh laid out four basic elements for the design from the very start. First, to reduce weight, increase endurance and keep it simple, the plane should be powered by a single engine. Second, for efficiency's sake it must be a monoplane. Third, it must carry at least 400 gallons of fuel with "a good power reserve on take-off" and, fourth, "it must have the pilot located in rear of all (fuel) tanks for safety in a forced landing." This last criteria, which Hall referred to as "the most radical feature of the design" in that it cut off forward vision, allegedly arose from Lindbergh's familiarity with certain disastrous hard landings in which pilots, sitting in between gas tanks and engine compartments, had been crushed to death.²

Hall's plan for the wings on the so-called "New York to Paris" (NYP) aircraft would be similar to those on the M-2, but as he wrote "it was necessary to increase the wing span by 10 feet". Elongated wings provided better long-range efficiency - and 10 miles per gallon was deemed essential. Longer wings would also reduce stress on takeoff for what promised to be, with the full fuel load aboard, a very heavy aircraft.

For stability's sake, the NYP plane's engine would be moved forward about 18" from the M-2 design, and the tail surfaces shifted 30" aft. Hall knew that the tail itself should also be larger. Designing, and then constructing a new tail assembly would be very difficult given the time constraints. Instead, Hall proposed using an M-2 tail, installed two feet farther aft of where it would normally sit. Hall assured Lindy the feathers would work, but admitted in the same breath that stability would be an issue. Ever the pragmatist, Lindbergh commented that the compromise had at least one positive aspect. A little instability would produce the need for fairly constant adjustments and go a long ways towards keeping him awake on his marathon flight.

Click to enlarge Equipped with wing struts and the main gas tank, the frame of the NYP plane sits inside the Ryan factory. In the background to the left is an M-2 under construction. This image, like most shown here, was likely snapped by factory photographer Maj. H.A. "Jimmy" Erickson.

Also making an endurance run on the flight would be the J-5C Whirlwind engine, which represented the latest in a long line of robust, air cooled, radial power plants designed by Wright. Its immediate predecessor the J-4, set a recognized endurance standard of 50 hours, and three J-4s powered Admiral Byrd's Fokker for his North Pole flight in 1926. Hall had faith in the J-5C, and a high regard for its 220 h.p. rating - 20 more horsepower than the J-4. Notably, most if not all of the other contestants for the Orteig Prize, including Byrd, flew aircraft equipped with J-5Cs. On the NYP plane, the engine connected directly to the frame without any kind of shock mounts. According to Cassagneres, this aspect of the design did not particularly trouble Lindbergh, who was used to a little vibration, but another did: the use of long continuous tubes for fuel and oil lines. Aware that such components could be subject to damage from expansion, contraction, and vibration, he insisted they be constructed out of segmented tubes. The concept was apparently not a new one, but its use on Lindy's plane later helped cement it as a standard construction practice throughout the aviation industry.

One item Hall omitted from the power plant was a carburetor air heater. It was a calculated risk -- Hall knew Lindy'd have to cross high mountains on his way from San Diego to New York and might have icing problems. The flight across the Atlantic however would be at low altitude, and the heater added weight and stole power³ . Lindy did in fact encounter performance problems on his cross-country flight, and after a discussion with Wright mechanics at Roosevelt Field, decided to allow them to install a heater wired permanently in the "on" position. "There may have been pros and cons on this arrangement," Ev Cassagneres notes, "But it may have been one of the secrets between success and failure." Like so many other things…

Click to enlarge A view of the left side of the cockpit. Just forward of the instrument panel sits the massive 209 gallon main gas tank. The control stick is visible just beneath the window frame and just in front of it sits the triangular-shaped trim adjustment lever. To the rear of the stick sits the throttle lever, and below that, the Earth Inductor Compass controller.

One of the least important features of the plane, but perhaps its most recognizable, was a happy accident. The Ryan Airlines factory burnished the cowlings of both the M-1 and M-2 with an intricate swirling pattern consisting of overlapped circles known as "engine turn". Thus the plane's six-piece cowling, held together by rivets and pins to allow quick access to the engine, received this jeweled finish as well. Upon it was painted "Spirit of St. Louis". That phrase, borrowed from a 1922 movie highlighting the city's achievements, honored Lindbergh's Missouri-based financial backers. It would soon be known the world over.

Famously, the plane had no forward windscreen. As with all aspects of the craft's design, function dictated form. The elimination of front-looking windows and the addition of streamlined fairings and the enclosed cockpit all cut down on drag. But beyond that, the design was more or less necessitated by having the main gas tanks sit in front of the pilot rather than behind him. Initially, Hall expressed concern over the arrangement, since it increased the chance of an accidental collision with electrical wires, buildings or terrain, and could make for difficult landings. Yet Lindbergh remained unmoved. He'd flown many airplanes with impaired forward visibility - as had Hall. For landing, both knew Lindy could use the left or right cabin window to line up with a runway, and then side-slip. Most of the time the forward view wouldn't matter anyway, since Lindy'd be flying by instrument.

Click to enlarge An early view of the instrument panel. It might appear rudimentary, but in 1927 it could be considered advanced. The instruments include: (l to r): fuel mixture lever, magneto switch, (top) Earth Inductor Compass indicator, (lower row) turn and bank indicator, (top) altimeter, (lower) air speed indicator, and 8-day clock. The center glass gauge is an inclinometer. The tube at the far right is Lindbergh's "Econometer", which never worked and was removed prior to the transatlantic attempt. Several other items were added later, including oil pressure and temperature gauges. At bottom are visible the series of valves used to route gas from various tanks.

Nevertheless, the notion that Lindbergh would be "flying blind" must have been a keen topic of conversation at the Ryan factory's water cooler. By happenstance a worker named Albert Randolph had experience aboard submarines and suggested that the plane be outfitted with a periscope. That concept eventually took the form of a telescoping box which provided a view out of the left side of the forward fuselage. Lindbergh and Hall initially felt the concept far-fetched, but once they saw the finished device it quickly gained their adherence. During test flights Lindy discovered he could easily steer and comfortably hold a course with the aid of the device, and he became a true believer.

According to Cassagneres, Hall exploited the rearwards cockpit design by placing the oil tank in between the cockpit and fuel tank as a firewall. An added and perhaps unexpected bonus was that the longer distance from the massive engine likely increased the accuracy of certain delicate instruments. The panel included an air speed indicator, bank and turn indicator, oil pressure and temperature gauges, a clock, a fuel pressure gauge, a tachometer, altimeter, and a liquid magnetic compass. Also on board was an Earth Inductor Compass - a brand new invention which although not infallible provided a fair level of accuracy for its day. One item the aircraft lacked were fuel gauges. Lindy refused to allow Hall to install them, insisting that they would only add unwanted weight. Besides he believed he could measure consumption more accurately using a piece of paper, the on-board clock and a device scratch built by Lindbergh called an "Econometer." (According to Ty Sundstrom, similar devices were in use aboard military aircraft, but when Lindy learned how expensive they were he decided he could save some money by building his own.) Alas, his design failed to work and the apparatus ended up being removed before the record flight. No problem, though: Lindy made do with a watch, a pen and a pad of paper instead.

From the pilot's seat fuel could be routed from any one of five tanks - in the final design the forward tank held 88 gallons, a main fuel tank 209, and three wing tanks held 153 for a total of 450 gallons -- through a series of valves located below the instrument panel. Fuel trim was adjusted in flight through the use of a hand-powered wobble pump, which also served as a back-up in case of a main pump failure. Fuel would be moved into the wing tanks, and then gravity fed into the engine.

Click to enlarge Detail shot showing the tailskid and the bungee cord to which it was attached. Because it had to absorb a tremendous amount of shock, the tailskid was constructed of special heat-treated steel also used for the wheel axles.

A single, simple wicker pilot's seat, appropriate to Lindbergh's stature, dominated the cockpit. The stick and rudder occupied standard positions, with the wobble pump and trim levers sitting on the left wall near the window. Just to the rear sat the throttle and spark advance lever. Should the engine fail in flight, Lindy had only one option: staying with the plane. He refused to consider taking a heavy parachute, or waste space and valuable weight on a radio or night flying equipment. He did, however, pack some survival supplies and a small rubber raft. Bold as his venture might be, he knew far too well the wages of arrogance to neglect these essentials.

Over the decades, a mythology has certainly developed that the NYP plane Donald Hall built was little more than a "flying gas tank." In some sense of the statement this is true of course, but it belittles the sophisticated nature of the enterprise and the approach taken to meet it. Every component on the aircraft was strictly scrutinized to eliminate mass and ensure reliability. All things met rigid criteria. According to Cassagneres, the gas tanks themselves were no exception to this rule. Assembled by hand, they underwent a painfully thorough inspection procedure intended to find bad rivets or handling damage which could promote the formation of leaks. Finally, in an effort to avoid chafing, minimize vibration and maximize capacity, Hall's design placed each tank precisely into the airframe with the main tank having only about 1/8th inch of clearance on either side of the fuselage frame. Such a commitment to detail put a strain on the Ryan workers. "The only good natured grumbling I've heard," Lindbergh wrote later, "was when Hall sent down drawings that called for the fuselage fairings to an accuracy of one thirty-second of an inch. Then Superintendent Bert Tindale remarked that he'd never before been asked to hold such accuracy. But I saw him working there the rest of the afternoon…" Despite Hall's best efforts, the shifting nature of the design and the lack of standard blueprints sometimes caused him to miscalculate. Hall initially estimated desired fuel capacity with safety factor at 380 gallons. Then, apparently at Lindbergh's insistence he revised that figure to 425 gallons. Yet as Ty Sundstrom notes, the finished plane somehow ended up with a 450 gallon capacity.

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This photo shows the 210-gallon main fuel tank built for the Japanese copy of Lindbergh's plane. Made from soft tin steel, it was constructed with baffles (detail) to minimize sloshing. The tank for the SOSL was larger than any ever built at Ryan, and employees initially speculated it was being constructed for use on a boat. (Note cut-outs visible at top of tank to accommodate pilot's feet).

The landing gear also testify to Hall's commitment to design detail. Desperate to eliminate weight and drag, Lindbergh and Hall considered many options, including equipping the plane with detachable wheels similar to those used on Orteig competitor Capt. Charles Nungesser's White Bird⁴ . True, this type of arrangement would save a great deal of weight in flight, and in theory Lindbergh only had to make one landing, but what if he had to turn back after ditching the gear? In the end a more conventional approach prevailed and Hall went with his original impulse, which was to copy a highly stable design employed by Fokker. Hall moved the wheels out of the slipstream, and spread the bearing loads through the fuselage and wing. The gear and tail strut relied on sets of thick but lightweight bungee cords for shock absorption.

While Donald Hall and his colleagues struggled to assemble his aircraft, Charles Lindbergh installed himself at a drafting table in Hall's office and pored over navigational charts purchased during a trip to San Pedro. Most of his efforts of course focused around the Atlantic flight although at one point, sensing that a competitor might beat him to Paris, he considered a possible Pacific flight from San Diego to Japan.

Click to enlarge Visible in this view: the Wright J-5C engine, the forward 88-gallon fuel tank, and the 27-gallon oil tank. The cowling on the plane has yet to be installed. The fuel lines leading from the tanks have clearly been segmented to prevent vibration and expansion/contraction damage. The fairings for the landing gear have yet to be installed, along with the propeller, spinner, and oh yes, the wing.

Although he had demonstrated uncanny skill as a pilot, could maintain a course better than most, and was among the first to fly by instrument, Lindbergh knew the Paris flight would tax his abilities. His navigational problems were not small ones. Hall wrote that "during four weeks practically all (Lindy's) waking hours were occupied by (the) study of navigation and the preparation of charts and data for use in a dead reckoning flight." Despite his considerable experience as an Air Mail pilot, Lindbergh actually had little technical knowledge of navigation except what he'd learned in the Army. Through a dedicated course of study using books from the San Diego Public Library and elsewhere, and attention paid to a "great circle route" guide printed on one of his charts, Lindbergh's knowledge grew and his plans gradually coalesced into a "curving, polygonic line, cutting fearlessly over thousands of miles of continent and ocean." Lindy's studiousness gave him enough confidence that, as Scott Berg wrote, he felt no need to bring a heavy radio or "even a sextant for further navigation". Either would have had serious shortcomings: the radios of the day lacked range, and there is no way to effectively use a sextant while at the same time flying a plane!

Whenever time allowed, Lindbergh tried to keep up his flying skills, touring Southern California in one of the Ryan company's monoplanes, and traveling to Los Angeles to pick up needed items. Since most of the craft Lindy had flown for the Air Mail had been bi-planes, the monoplane flights also provided some valuable experience. According to Ty Sundstrom, who has studied Charles Lindbergh's correspondence from his time in San Diego, Lindy actually spent far more time away from the hectic scene at Ryan than he let on in his memoirs. A little wanderlust is understandable, as Lindy certainly understood he might perish as a result of his venture. Regardless, at some point he returned to Ryan Airlines and rejoined Hall. Douglas Corrigan, a Ryan mechanic who later earned the famous "Wrong Way" nickname, remembered that "Lindbergh was around the plant every day showing the mechanics how he wanted certain parts put in and checking over the load factors and estimated performance figures…" Under ordinary circumstances the presence of such an overseer might have upset the staff, but Lindy's affable manner reportedly put everyone at ease. He had already earned the loyalty and admiration of the workers, and benefited from their hard work. Many of the employees toiled into the wee hours without added pay simply because they recognized that the future of the company - and the course of history -- hung in the balance.

Click to enlarge On April 26, the fuselage of the NYP plane was hauled from the Ryan factory to the airfield at Dutch Flats for final assembly. Here, the plane passes Juniper Street attached to the rear of Claude Ryan's Studebaker. The car in the rear is probably Donald Hall's Buick. The strange-looking wheels on the aircraft are temporaries rigged up for the move.

One of the last components to be finished was the plane's long, one-piece wing. It was the most labor-intensive structure on the aircraft, and work began upon it even before Lindbergh arrived in San Diego to sign the contract. To further speed up assembly, or simply because it was handy, Hall borrowed the rib design from the M-2.⁵ That was where any similarity more or less ended. Thanks to a series of tapered spar caps that allowed for a reduction in cross section, the NYP plane's wing could carry a great deal of gas, yet as Ty Sundstrom points out, it weighed less than the M-2's wing while being 10' longer. It also had specially designed wing tips shaped so as to minimize drag. The end product cast the form of a Clark "Y" airfoil, and was actually one of the few components that ended up on something remotely resembling a fully-detailed blueprint. For the most part, Hall relied on his agile memory and a series of rough sketches to keep the design straight - there apparently just wasn't time to make normal schematics. On one occasion, trying to keep a step ahead of the factory workers, Hall sketched for over thirty-six hours non-stop at his drawing board. It was a feat Lindbergh might have regarded with more than passing interest. He'd after all have to match Hall's wakefulness, and then some, to fulfill his end of the bargain.

The efforts made by the staff at Ryan cannot be underestimated, either. Well versed in the assembly of aircraft and the improvisational skill required to construct a flight-worthy plane with a paucity of direction, they proved more than capable. The burden placed on Bowlus, Morrow, Tindale and their underlings was obviously tremendous, especially given the lack of conventional schematics and the short schedule. Lindbergh gave them all the credit in the world, noting that "Each of them is striving to do a quicker and better job on the Spirit of St. Louis than he's done before. No pains are too great, and no hours too long; lights sometimes burn in the factory all through the night."

Click to enlarge There was a bit of hand wringing when it was discovered that the wing would not fit through the door of the factory's second-story assembly room. Fortunately, it would fit out one of the veranda-type windows. Using a handy box-car as a platform, the staff was able to get the wing outside. Then a derrick, visible to the far left, placed the wing into the bed of the truck visible in the foreground.

The NYP plane's big wing produced a rather amusing episode. After the span was fully assembled, the realization took hold that it was too big to maneuver out the door of the workshop. The room sat on the second floor loft of the factory, which made the situation all that more tricky. A quick examination of the available options, which included widening the egress with a sledge hammer, revealed that the wing might just fit out one of the second floor's full-height windows. Beneath the window ran a railroad spur, and the wing was therefore moved out of the window onto the roof of a handy box car borrowed for the occasion. It was then moved to a truck with the aid of a small crane. Fortunately, the entire harrowing maneuver went off without a hitch.

On April 25, at two o'clock in the morning, factory work was pronounced complete on the plane. By now it had an official license number from the new Aeronautics Branch of the Department of Commerce: N-X-211 (N designating United States, X for experimental). Remarkably, only fifty-nine days had elapsed from the date the order for the plane had been placed. But there was no time to celebrate. The plane was cautiously towed a couple miles to Dutch Flats, a field on the edge of San Diego which the company used for testing, and the wing bolted on. A little while later, a Standard Steel Propeller was attached along with an "engine turned" spinner.

On the 28th, Lindbergh attempted his first flight. With the entire factory staff looking on, the engine was hand propped by a couple employees, including Corrigan. The plane's J-5C responded, and moments later the wheel chocks were removed and Lindy taxied down the muddy field and took off. With only fifty gallons of gas aboard, the plane left the ground in just over six seconds and less than 100 feet. It accelerated faster than anything Lindbergh had ever flown, and he marveled at it. After checking that his instruments were working he buzzed the Ryan factory and then headed out over San Diego Bay. On the way, he proceeded to run some tests, put the plane into a stall, and couldn't resist the temptation to open up the throttle. The airspeed indicator quickly hit 128 mph and he backed off. When a Navy Hawk appeared from the nearby military field, Lindy engaged in some unplanned maneuvers. He banked towards the fighter and engaged in a mock dogfight, noting with satisfaction that although the Navy plane was faster, his craft could turn in a shorter radius. Then he called it quits and returned to Dutch Flats, performing a few more stalls along the way. All in all the plane had performed well, despite the expected stability issues.⁶

Click to enlarge With a heave-ho, the forty-six foot long wing is hoisted into position. The skylight in the center of the wing is clearly visible. Douglas "Wrong Way" Corrigan stands just in front of the tail feathers. Lindbergh is the fifth person from the left. Presumably Donald Hall is also in the photo. Possibly that's him immediately adjacent to the aircraft on the right side, hand just grazing the skylight.

Even though it only lasted twenty minutes, the first flight was a triumph for everyone concerned. A celebratory photo was snapped after it ended. Lined up under the wings of the plane, the exhausted factory workers, B.F. Mahoney and Donald Hall could take some satisfaction. But all present that day knew that for Lindbergh the journey had in a real sense just begun. In front of him lay a destiny they could no longer directly affect. They had done their best. Now everything was up to the young pilot.

Ten days after test flights commenced, Lindbergh left San Diego and flew cross-country to St. Louis, and from there on to Curtiss Field, New York. The staff at Ryan, like everyone around the nation, monitored Lindy's attempt, and the celebration in San Diego when he succeeded was as raucous as anywhere in the world. "When the news reached San Diego," remembered Douglas Corrigan, "the whole town went wild because the people knew the plane was a local product. All the fellows from the factory and the field jumped into cars and rode through the streets waving and shouting." From a human and an engineering standpoint the achievement was wholly remarkable. Even for the modest Hall, the sense of accomplishment must have been terrific. He'd been part of an incredible venture, and the craft he'd supervised had performed in spectacular fashion. According to the press reports, when Lindy had landed in Paris he'd had enough fuel aboard to have flown onwards, perhaps even as far as Rome.

Donald Hall and B.F. Mahoney were invited to attend the festivities welcoming Lindbergh back to New York in June, and were there when Lindy received the Orteig Prize for which he'd worked so long and hard, and for which he'd risked so much. The press of course idolized the tall, handsome, brave pilot they dubbed "Lucky Lindy". Some attention was directed to others involved in the effort, but the monumentality of Lindbergh's efforts meant that he inevitably received the lion's share of the laurels. Ev Cassagneres believes that Donald Hall's achievement in designing and building a groundbreaking aircraft was overlooked. "Lindbergh became a household word, an American hero, and still admired around the world, even up to the present time," he says. "Donald A. Hall however, never did receive the acclaim he most certainly deserved for the part he played in the success of the flight."

Click to enlarge Spirit, seen from the right side. The single cockpit door is clearly visible. The small protuberance about midway down the tail is a wind-driven generator for the Earth Inductor Compass. The craft measured just under 28 feet long, from spinner to tail. It might have looked like an all-metal design, but of course the fairings were made of balsa, and much of the exterior was covered with aluminum-painted cotton fabric. When Lindy landed at Le Bourget Field, Paris, exuberant crowds tore off swaths of fabric and broke stringers in the fuselage before gendarmes intervened.

Others such as John Underwood differ, noting that while Hall's efforts were certainly diligent, they should not be considered revolutionary. "Donald Hall was no more than a competent engineer and what he did was not particularly brilliant from an engineering standpoint," he notes. Ty Sundstrom concurs, suggesting that while the Spirit was unique, its design could not be considered state of the art for 1927 and, by most measures, it was in fact obsolete. "Even Charles Lindbergh said later that the best aircraft for the flight was the Wright-Bellanca," he notes. "The Spirit was actually (based on) an outdated design that was revamped to make it across the Atlantic. It was built to the slimmest of safety margins and needed every effort to make it successful." In Sundstrom's estimation, Hall's most important accomplishment lies in something largely overlooked over the years, namely his determined effort to streamline an existing design and effectively increase the craft's range. An important achievement that paid significant dividends, but not an extraordinary one by any measure.

For Nova Hall, the debate surrounding his grandfather's role is somewhat moot. "The fact that we're even having a debate is what's important," he notes. "For so many years my grandfather's role was minimized by Ryan (and B.F. Mahoney). His name was hardly mentioned." Since discovering the trunk full of photographs, Nova has written a book about his grandfather and feels he's come to know him in the process. "I'm now an expert on my grandfather, who he was, what he did, and that's what my book is about - the mysterious man behind Lindbergh, " he says. "The man I never met, but whom I cherish for who he was."

Among the photos Nova discovered in his grandfather's trunk, is one that shows him at the controls of a tandem wing plane. This is the Hall Aeronautical Development X-1, which he designed after leaving Mahoney-Ryan Airlines in 1929. The plane represented Donald Hall's second chance for public acclaim. Touted in the press as "a fast, highly maneuverable" aircraft, it apparently had less than spectacular performance characteristics. Lindbergh flew it during a trip to San Diego, and while his reaction was not recorded he apparently did not endorse it or choose to invest in it. The plane never shed its experimental designation, and the Great Depression soon forced the company to close its doors. A disappointed Donald Hall struggled for a time, and then eventually resumed his design career working for a series of companies including Convair, where he helped design the B-24 Liberator. Thus in some respects, building the Spirit proved to be the high water mark of his career.

If there was any bitterness between Donald Hall and Charles Lindbergh over the X-1, it was likely never discussed. The two friends kept in touch over the years, according to Nova Hall, maintaining a cordial correspondence and occasionally visiting one another. Perhaps on one of those visits they reminisced about the day, May 3, 1927 -- just before Lindy flew the Spirit from San Diego to St. Louis and on to glory -- when the pilot invited the designing engineer to ride in the cramped cockpit of the NYP plane. The sun ducked in and out of a light fog that day as Lindy put the aircraft through its paces, letting Hall handle the stick briefly so as to get a sense of the stability issues produced by the insufficiently large tail. True, the plane had some eccentricities, but it seemed to fly marvelously well.

^1. Levine later recruited pilot Clarence Chamberlin, and became a serious contender in the Orteig race. Two weeks after Lindy made history, the pair broke his distance record by flying the Bellanca from New York to Germany. The same plane would make history again a short time later by becoming the first to cross the Atlantic a second time.

^2. According to Sundstrom, the real reason for the arrangement may have been far more mundane. "Lindbergh and Hall said they designed the plane so he'd sit in the rear, behind the fuel tanks, for safety," Sundstrom says. "But the truth is the seat was located in the rear to provide for proper balance, by putting the fuel near the center of gravity. All previous Ryan planes had the same configuration."

^3. John Underwood notes that, while flying as an Air Mail pilot, Lindy learned how to clear carburetor ice by deliberately backfiring the engine. Certainly he was no stranger to the phenomenon and could have dealt with any problems on the NYP plane in similar fashion.

^4. The plane and crew disappeared during an attempted Atlantic crossing just days after the NYP's first flight.

^5. The wing ribs may not have been the only significant component to be assembled prior to the contract being signed. According to Ty Sundstrom, parts of the plane may have been constituted from some pre-fabricated elements built and stored at the Ryan factory.

^6. Although it is recounted in his book The Spirit of St. Louis, some believe Lindy's dogfight story to be apocryphal.

Additional Pictures:

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Handsome shots of the left side of the plane. The top image clearly shows the position of the periscope. Lindbergh was initially skeptical of the viewing device, but allowed it to be installed after Hall assured him it would have only a small impact on the plane's aerodynamics. It worked well, allowing Lindy to see forward without having to lean to one side of the cockpit. Yet he used it only minimally, mostly at low altitude to sight smokestacks and other obstacles. He never used it for takeoff and landing - that would have been, in his words, "impracticable."		Detail shot showing the "engine turn" covered cowling and spinner, the nine-foot diameter Standard steel propeller, the air-cooled J-5C engine, and Fokker-type landing gear. The slightly blunted spinner seen in this photo was replaced in New York with a much more aerodynamic design, which lacked the engine turn finish.	April 28, 1927. With a roar, the Spirit of St. Louis takes off on its maiden flight. Lindbergh was heartened at the acceleration produced by the J-5C, which had him and 50 gallons of gas off the ground in less than 100 feet. A few minutes later, Lindy buzzed the Ryan factory. Note lack of fairings over the plane's landing gear shock mounts. They wouldn't be added until after the initial flight.
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Assembled in this group photo is the team that built the plane that made history. Hall is fourth from the right; Lindbergh is visible just to the left of the propeller wearing a borrowed hat. Women employees were not uncommon at aircraft manufacturers in this era - at Ryan they sewed all the fabric. Note the cowling cover on the ground at the right side of the image.	Both Lindbergh and Hall felt that fuel load tests should be conducted with the Spirit, but the short runway at Dutch Flats made that a risky undertaking. The group moved to the ample-sized parade grounds at Camp Kearney, near San Diego, and Lindy flew with fuel loads up to and a little over the 300 gallon mark. At that point the risk of accident on the rock-strewn field was felt to be too great, and the tests discontinued.	A somewhat controversial photo, shot (depending on who you talk to) either by Donald Hall during a trip aloft with Lindbergh on May 3rd, or by "Jimmy" Erickson on May 5th. Undoubtedly it was one of the first photos ever taken from the Spirit. According to his grandson Nova, Donald Hall sat on the armrest of Lindy's pilot seat while aloft so he could study the instrument panel, and Lindy briefly yielded the stick at altitude so that the designing engineer could get a sense of the plane's stability issues.	On May 10, Lindbergh began the first leg of his cross-country odyssey. In this photo, Lindbergh poses next to Hall while the plane is fueled using jerry cans and a funnel. About 250 gallons were loaded for the trip. (Photo Courtesy Ryan Aeronautical Company via Ev Cassagneres)
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On May 10, Donald Hall and a few Ryan employees jumped aboard a chase aircraft and accompanied Lindy at the beginning of his cross-country trip. As Hall and his compatriots turned back towards Dutch Flats, one can only guess at the emotions they felt. No one could have been certain that Lindy would succeed, or even survive. When he did, the sense of triumph and relief must have been overwhelming.	Plan view of the Spirit of St. Louis prepared by Donald Hall for Aero Digest.	The Hall X-1. Equipped with a low main wing, this plane was touted in the press as being both exceptionally stable and highly maneuverable. Apparently it wasn't, and the prototype ended up being the only one built. Hall eventually was forced to give up the dream of having his own aircraft company. While Lindbergh soared to new heights in terms of fame, Donald Hall led a productive, and apparently happy life of relative obscurity.





SPECIAL THANKS AND CREDITS

Presented in this article are photos retrieved from Donald Hall's "lost" archive. Special thanks are owed to Nova Hall, David Pashman and The Donald Hall Sr. Estate for permission to reprint these copywritten materials herein. These and many others items are showcased in Nova Hall's recently published tribute to his grandfather, Spirit and Creator: The Mysterious Man Behind Lindbergh's Flight to Paris. I also appreciate the efforts of Ev Cassagneres, author of The Untold Story of the Spirit of St. Louis, who interpreted many of the items in the Hall collection. Finally, sincere thanks are due to Ty Sundstrom and John Underwood for sharing some of their soon-to-be-published research and opinions, for patiently reading early drafts, and to the marvelous Mike Gretz for his suggestions and fact checking.

Nick T. Spark is a frequent contributor to Wings and Airpower magazines. His articles have also appeared in Naval History, Proceedings, the American Aviation Historical Society Journal, the Annals of Improbable Research, and U.S.C. Trojan Magazine. His documentary film "Regulus: The First Nuclear Missile Submarines" (www.regulus-missile.com) has aired on Discovery Channel Europe and was recently released on DVD.