Spirit of St. Louis
The Spirit of St. Louis is the custom-built, single-engine, single-seat, high-wing monoplane that Charles Lindbergh flew on May 20–21, 1927, on the first solo nonstop transatlantic flight from Long Island, New York, to Paris, France, for which Lindbergh won the $25,000 Orteig Prize.
Lindbergh took off in the Spirit from Roosevelt Airfield in Garden City, New York, and landed 33 hours, 30 minutes later at Aéroport Le Bourget in Paris, a distance of approximately 3,600 miles. He also flew this aircraft on numerous occasions, delivering mail in and out of the United States. One of the best-known aircraft in the world, the Spirit was built by Ryan Airlines in San Diego, California, owned and operated at the time by Benjamin Franklin Mahoney, who had purchased it from its founder, T. Claude Ryan, in 1926. The Spirit is on permanent display at the Smithsonian Institution's National Air and Space Museum in Washington, D.C. The exhibit, Pioneers of Flight, has reopened following extensive renovation and modernization.
Development
Officially known as the "Ryan NYP", the single-engine monoplane was designed by Donald A. Hall of Ryan Airlines and named the "Spirit of St. Louis" in honor of Lindbergh's supporters from the St. Louis Raquette Club in his then hometown of St. Louis, Missouri. To save design time, the NYP was loosely based on the company's 1926 Ryan M-2 mailplane, the main difference being the NYP's range. As a nonstandard design, the government assigned it the registration number N-X-211. Hall documented his design in "Engineering Data on the Spirit of St. Louis", which he prepared for the National Advisory Committee for Aeronautics and is included as an appendix to Lindbergh's 1953 Pulitzer Prize winning book The Spirit of St. Louis.B.F. "Frank" Mahoney and Claude Ryan had co-founded the company as an airline in 1925 and Ryan remained with the company after Mahoney bought out his interest in 1926, although there is some dispute as to how involved Ryan may have been in its management after selling his share. It is known, however, that Hawley Bowlus was the factory manager who oversaw construction of the Ryan NYP, and that Mahoney was the sole owner at the time of Donald A. Hall's hiring.
The Spirit was designed and built in San Diego to compete for the $25,000 Orteig Prize for the first nonstop flight between New York and Paris. Hall and Ryan Airlines staff worked closely with Lindbergh to design and build the Spirit in just 60 days. Although what was actually paid to Ryan Airlines for the project is not clear, Mahoney agreed to build the plane for $6,000 and said that there would be no profit; he offered an engine, instruments, etc. at cost. After first approaching several major aircraft manufacturers without success, in early February 1927 Lindbergh, who as a U.S. Air Mail pilot was familiar with the good record of the M-1 with Pacific Air Transport, wired, "Can you construct Whirlwind engine plane capable flying nonstop between New York and Paris...?"
Mahoney was away from the factory, but Ryan answered, "Can build plane similar M-1 but larger wings... delivery about three months." Lindbergh wired back that due to competition, delivery in less than three months was essential. Many years later, John van der Linde, chief mechanic of Ryan Airlines, recalled, "But nothing fazed B.F. Mahoney, the young sportsman who had just bought Ryan." Mahoney telegraphed Lindbergh back the same day: "Can complete in two months."
Lindbergh arrived in San Diego on February 23 and toured the factory with Mahoney, meeting Bowlus, chief engineer Donald Hall, and sales manager A. J. Edwards. After further discussions between Mahoney, Hall and Lindbergh, Mahoney offered to build the Spirit for $10,580, restating his commitment to deliver it in 60 days. Lindbergh contributed $2,000 toward the cost of the Spirit that he had saved from his earnings as an Air Mail pilot for Robertson Aircraft Corporation. The rest was provided by the Spirit of St. Louis Organization.
Lindbergh was convinced: "I believe in Hall's ability; I like Mahoney's enthusiasm. I have confidence in the character of the workmen I've met." He then went to the airfield to familiarize himself with a Ryan aircraft, either an M-1 or an M-2, then telegraphed his St. Louis backers and recommended the deal, which was quickly approved.
Mahoney lived up to his commitment. Working exclusively on the aircraft and closely with Lindbergh, the staff completed the Spirit of St. Louis 60 days after Lindbergh arrived in San Diego. Powered by a Wright Whirlwind J-5C 223-hp radial engine, it had a 14 m wingspan, 3 m longer than the M-1, to accommodate the heavy load of 1,610 L of fuel. In his 1927 book We, Lindbergh acknowledged the builders' achievement with a photograph captioned "The Men Who Made the Plane", identifying: "B. Franklin Mahoney, president, Ryan Airlines", Bowlus, Hall and Edwards standing with the aviator in front of the completed aircraft.
Design
Lindbergh believed that multiple engines resulted in a greater risk of failure while a single-engine design would give him greater range. To increase fuel efficiency, the Spirit of St. Louis was also one of the most advanced and aerodynamically streamlined designs of its era, as detailed by Popular Science magazine in 1957: "The fuselage curved from spinner to tail in one unbroken line. All struts were faired with balsa, then covered with sheet aluminum. The shock absorbers were streamlined. Even the wheels were covered with a doped fabric. The gap between fin and rudder was sealed with a strip of fabric. And the engine cowling was faired into the fuselage. The result of this unheard-of streamlining was a maximum speed ten m.p.h. higher than that of the M-2--even though The Spirit of St. Louis weighed twice as much!"Lindbergh believed that a flight made in a single-seat monoplane designed around the dependable Wright J-5 Whirlwind radial engine provided the best chance of success. The Ryan NYP had a total fuel capacity of or of gasoline, which was necessary in order to have the range to make the anticipated flight non-stop. The fuel was stored in five fuel tanks, a forward tank –, the main –, and three wing tanks – total of. Lindbergh modified the design of the plane's "trombone struts" attached to the landing gear to provide a wider wheelbase in order to accommodate the weight of the fuel.
At Lindbergh's request, the large main and forward fuel tanks were placed in the forward section of the fuselage, in front of the pilot, with the oil tank acting as a firewall. This arrangement improved the center of gravity and reduced the risk of the pilot being crushed to death between the main tank and the engine in the event of a crash. This design decision meant that there could be no front windshield, and that forward visibility would be limited to the side windows. This did not concern Lindbergh as he was accustomed to flying in the rear cockpit of mail planes with mail bags in the front. When he wanted to see forward, he would slightly yaw the aircraft and look out the side. To provide some forward vision as a precaution against hitting ship masts, trees, or structures while flying at low altitude, a Ryan employee who had served in the submarine service installed a periscope which Lindbergh helped design. It is unclear whether the periscope was used during the flight. The instrument panel housed fuel pressure, oil pressure and temperature gauges, a clock, altimeter, tachometer, airspeed indicator, bank and turn indicator, and a liquid magnetic compass. The main compass was mounted behind Lindbergh in the cockpit, and he read it using the mirror from a women's makeup case which was mounted to the ceiling using chewing gum. Lindbergh also installed a newly developed Earth Inductor Compass made by the Pioneer Instrument Company which allowed him to more accurately navigate while taking account of the magnetic declination of the earth. Lindbergh's ultimate arrival in Ireland deviated from his flight plan by just a few miles.
Lindbergh sat in a cramped cockpit which was in width, length, and height. It was so small, Lindbergh could not stretch his legs, nevertheless it was to be his home for nearly two days and nights over the Atlantic. The Spirit of St. Louis was powered by a, air-cooled, nine-cylinder Wright J-5C Whirlwind radial engine, by most accounts an exceptionally engineered powerplant by engineer Charles Lawrance. The engine was rated for a maximum operating time of 9,000 hours and had a special mechanism that could keep it clean for the entire New York-to-Paris flight. It was also, for its day, very fuel-efficient, enabling longer flights carrying less fuel weight for given distances. Another key feature of the Whirlwind radial engine was that it was rated to self-lubricate the engine's valves for 40 hours continuously. Lubricating, or "greasing," the moving external engine parts was a necessity most aeronautical engines of the day required, to be done manually by the pilot or ground crew prior to every flight and would have been otherwise required somehow to be done during the long flight.
The engine was built at Wright Aeronautical in Paterson, New Jersey, by a 24-year-old engine builder, Tom Rutledge, who was disappointed that he was assigned to the unknown aviator, Lindbergh. Four days after the flight, he received a letter of congratulations from the Wright management.
The race to win the prize required time-saving design compromises. Donald A. Hall decided that the empennage and wing control surfaces would not be altered from his original Ryan M-2 design, thus minimizing redesign time that was not available without delaying the flight. The result was less aerodynamic stability; nevertheless, the experienced Lindbergh approved the unaltered design. This setup resulted in a negatively stable design that tended to randomly introduce unanticipated pitch, yaw, and bank elements into its overall flight characteristics. There is a dispute regarding whether Hall and Lindbergh also preferred this design because they anticipated that the continuous corrections to the random movements of the aircraft would help to keep Lindbergh awake during the estimated 40-hour flight. Whether or not the unstable design was deliberately retained to help fight fatigue, Lindbergh did later write how these random unanticipated movements helped keep him awake at various times during the flight. The stiff wicker seat in the cockpit was also purposely uncomfortable, although custom-fitted to Lindbergh's tall and lanky frame.
Lindbergh also insisted that unnecessary weight be eliminated, even going so far as to cut the top and bottom off of his flight map. He carried no radio in order to save weight and because the radios of the period were unreliable and difficult to use while flying solo. Also, although he was an airmail pilot, he refused to carry souvenir letters on the transatlantic journey, insisting that every spare ounce be devoted to fuel. The fuselage was made of treated fabric over a metal tube frame, while the wings were made of fabric over a wood frame. The plywood material that was used to build most of Lindbergh's plane was made at the Haskelite Manufacturing Corporation in Grand Rapids, Michigan.
A small, left-facing Indian-style swastika was painted on the inside of the original propeller spinner of the Spirit of St. Louis along with the names of all the Ryan Aircraft employees, including Dapper Dan, who designed and built it. It was meant as a message of good luck prior to Lindbergh's solo Atlantic crossing as the symbol was often used as a popular good luck charm with early aviators and others. The inside of the original propeller spinner can be viewed at the National Air and Space Museum. This propeller spinner was found to be cracked when Lindbergh arrived at New York prior to his transatlantic flight. A replacement was hastily made in New York to replace the cracked original and was on the aircraft during the transatlantic flight.