|Lawrence Bell, founder of Bell Aircraft|
In his book The Bell Helicopter Textron Story, David Brown says of Larry Bell, the founder of Bell Aircraft, "Larry Bell was different. With the visionary's eye, he saw his first helicopter and was impressed. When he saw his second (helicopter), he understood that here was an industry waiting to be born." Larry Bell was one of the early American aviation pioneers- after high school he worked as his older brother Grover's mechanic for several years while his brother conducted barnstorming flights. In 1913, his brother was fatally injured in a crash and Bell resolved to stay away from aviation. It wouldn't last, though. He first went to work for his brother's flight instructor, Glenn L. Martin, as a stockroom clerk in Martin's fledgling aviation company. He advanced quickly through the company and ultimately ended up as the Martin Aircraft vice-president and general manager. It was Bell who hired the first college-educated aeronautical engineer for the company- a young MIT graduate named Donald Douglas. It was Bell who got the Army interested in a heavy bomber called the Martin MB-2 that was one of Douglas' early projects. And it was Bell who convinced a brash Army aviator named Billy Mitchell to use the MB-2 to prove that bombers could sink battleships. In 1925, Bell asked to own stock in Martin but Glenn Martin rebuffed his offer of part ownership of the company. Bell resigned and within three years was hired by Rueben Fleet, the president of Consolidated Aircraft. Fleet allowed Bell to own a sizable portion of Consolidated shares and by 1929 he was promoted by Fleet to be the general manager of Consolidated. In 1935, Fleet wanted to move Consolidated from Buffalo, New York, to southern California to take advantage of the better flying weather. Bell didn't want to move, so he resigned but a group of investors backed him in purchasing Consolidated's facilities in Buffalo for the new Bell Aircraft Company. Interestingly, Bell was the third tenant of the factory- it was originally built in 1916 for Glenn Curtiss and at the time was considered the largest aircraft factory in the world.
Bell's first aircraft was the YFM-1 Airacuda (Bell Model 1) which was a heavy bomber destroyer twin engined fighter. Only thirteen of the unique pusher twins were built and only a single squadron of Airacudas was activated as it was an aircraft ahead of its time. But the US Army Air Corps liked Bell's innovative thinking and asked him for a heavily-armed single engined fighter and this became the Bell Model 12, better known as the P-39 Airacobra which first flew in 1938. It was a remarkable start for Bell's fledgling company and in 1938, President Franklin D. Roosevelt asked Bell to join a group of American industrialists who had been invited tour Nazi Germany. Roosevelt wanted an expert opinion of Germany industrial capacity from the group and Bell was asked to join to assess the Nazi's aviation capabilities. Bell witnessed a flight demonstration of the Focke-Wulf Fw 61 helicopter flown by Hanna Reitsch and he considered the most impressive thing he'd seen on his tour of Germany.
That was the first helicopter Larry Bell saw- to get to the second helicopter he saw in 1941, we have to step back a bit to look at the story of a unique inventor named Arthur Young. A native of Pennsylvania, while a student at Princeton University, Young was very interested in philosophy and tried to develop an original line of philosophical thought but was unsuccessful. He decided that he wouldn't be able to do so without some real-world experience solving problems. Graduating from Princeton in 1927 with a mathematics degree, Young searched for a technical challenge. He scoured city libraries in the East Coast and made regular visits to the US Patent Office in Washington in his search. He came across a book in his searches by German helicopter pioneer Anton Flettner who had invented a ship that used the Magnus effect from rotary drums to sail across the Atlantic. Flettner had described improving windmill efficiency by using small propellers at the tips. Young thought Flettner's concept could be applied to aircraft and of course that aircraft would be the helicopter, one of the unique flying machines of the day. He set himself on the task of developing a successful helicopter.
|Arthur Young and one of his late helicopter models|
(State Archives of Florida, Steinmetz Collection)
Young set up an experimental workshop in a barn on his wealthy family's large estate in Pennsylvania. He refined his ideas using small models and his first design flew in 1931 using parts he obtained from a local toy shop- using rubber bands, hand-carved wooden blades with propellers at the tips and a balsa structure, his first model had a rotor diameter of six feet and it flew for only ten seconds. For the next nine years he worked at improving the Flettner concept, moving to the use of electric motors. He went through so many crashed models he literally learned how to mass produce his own helicopter blades. One of the problems Young encountered was getting his models into a stable hover. Over time he used his mathematics background to calculate stresses and build his own components based on his stress calculations. In doing so, he developed many of the concepts and tools used to measure rotor lift, propeller efficiency as well as equations to calculate a variety of power requirements for helicopters.
In 1938, Young attended a conference of helicopter designers and learned of the pioneering work of Igor Sikorsky. Sikorsky himself gave a lecture on the use of a tail rotor to counter the torque of the main rotor. Young was fascinated by Sikorsky's lecture and set about to revise his model testbeds with tail rotors, disposing of the complex gearing that he had been working on to drive tip propellers. Stability in a hover continued to plague his efforts- he had tried a pendulum within the fuselage, but the pendulum arrangement he designed couldn't distinguish between the force of gravity and the force of acceleration. He then came up with the stabilizer bar- a bar with weights on the end that was perpendicular to the rotor. The weighted bar when spinning acted as a gyroscope that stabilized the helicopter in a hover. He used an electrical control system that ran to a box where he controlled the helicopter with extreme precision. He took his models on demonstrations to various aircraft companies where he showed how he could fly his helicopter models indoors and even in and out of doorways. He even gave a demonstration to the Army's aeronautical development center at Wright Field in Dayton, Ohio, but failed to find any financial backers.
Dr. John Sharp was a physician who had seen one of Arthur Young's demonstrations. Sharp had a unique hobby in that he designed gearing systems in his free time and was working on a new gearing concept for a variable pitch propeller was pitching his ideas to Bell Aircraft. In 1941, Sharp was meeting with a Bell engineer named Jack Strickler and in casual conversation, Sharp spoke highly of Young's helicopter flight demonstrations. Strickler than passed on what Sharp told him to Larry Bell himself. Since Bell was impressed with what he had seen with the Focke-Wulf Fw 61 helicopter in his 1938 tour of Germany, he invited Arthur Young to come to Buffalo to give a demonstration of his helicopter design.
On 3 September 1941, Young arrived at Bell's Buffalo plant and was taken to a hangar where P-39s were prepared for delivery. Bell ordered the personnel in the hanger to stop work and move the P-39s outside to give Young room for his demonstration. Not only did Young fly a successful demonstration for Larry Bell, he also reviewed with Bell films showing his previous design efforts and showed him his notes on the design process he had developed to solve the problems of vertical flight. Bell was enthralled by Arthur Young and wanted to hear Young's ideas on a full-size piloted helicopter design. In a matter of weeks they reached an agreement where Young would come to Buffalo and work for Bell in developing a new helicopter based on his designs. Young assigned his patents to Bell Aircraft and Larry Bell funded the development of two full-sized helicopters. Young wanted two aircraft in case one crashed and Bell insisted that the second prototype be a two-seater so he could go on a ride!
The rest, as they say, was history! That first helicopter, the Bell Model 30, will be the subject of a future article here at Tails Through Time. Stay tuned!
BONUS: A three part interview with Arthur Young in his later years about his design efforts
Sources: The Bell Helicopter Textron Story: Changing the Way the World Flies by David A. Brown. Aerofax Publications, 1995, pp 1-19. "Arthur Young: Maker of Bell, Part 1" by Robert Tipton, http://www.arthuryoung.com/maker1.html.