Glidden Doman (January 28, 1921 – June 6, 2016) was an American aeronautical engineer and pioneer in helicopters and modern wind turbines. He founded one of America’s original six helicopter companies (Doman Helicopters, Inc.) after making major contributions to the use of Sikorsky helicopters during World War II. Doman Helicopters’ most prominent achievement was the Doman LZ-5 / YH-31 eight-seat helicopter, which received FAA certification on December 30, 1955. The unique feature of this helicopter was its hinge-less gimbaled, tilting rotor hub that greatly reduced stress and vibration in the blades and in the helicopter. Doman was one of the first to transfer knowledge of helicopter rotor dynamics technology to wind turbines. The 1973 Arab oil embargo prompted NASA Glenn Research Center in Cleveland, Ohio to lead a 7-year US wind energy program for the development of utility-scale horizontal axis wind turbines. This program featured the creation of Boeing’s MOD-2 with the Doman conceived flexible rotor design, two-bladed wind turbine with a teeter hinge. Following the NASA project, while working for Boeing, Hamilton Standard division of United Technologies, and Aeritalia in Italy, Doman developed large two-bladed, teeter-hinged wind turbines, including the WTS-3, WTS-4 , and the Gamma 60. After testing the Gamma 60 in Sardinia for 7 years, Doman and Italian nuclear mechanical engineer Silvestro Caruso founded Gamma Ventures, Inc. to further develop and market this technology. Gamma Ventures, subsequently invested and licensed to Seawind of the Netherlands, to commercialize the same two-bladed, teeter-hinge wind turbine concept. Doman, along with noted German-born aerospace engineer Kurt Hohenemser (a partner and confidant of the well-known German airplane and helicopter designer Anton Flettner), maintained that a flexible two-bladed helicopter type wind turbine rotor design that is compliant with the forces This type of wind turbine is a type of wind turbine that, by design, can only be constructed to resist the forces of nature. Two of Doman’s helicopters, the converted Sikorsky R-6 (Doman LZ-1A) and a Doman LZ-5 / YH-31, are on display at the New England Air Museum in Windsor Locks, Connecticut. along with noted German-born aerospace engineer Kurt Hohenemser (a partner and confidant of the well-known German airplane and helicopter designer Anton Flettner), maintained that a flexible two-bladed helicopter type wind turbine rotor design that is compliant with the forces of nature This type of wind turbine is more suitable for the production of standard wind turbine than rotors, which, by design, can only be constructed to resist the forces of nature. Two of Doman’s helicopters, the converted Sikorsky R-6 (Doman LZ-1A) and a Doman LZ-5 / YH-31, are on display at the New England Air Museum in Windsor Locks, Connecticut. along with noted German-born aerospace engineer Kurt Hohenemser (a partner and confidant of the well-known German airplane and helicopter designer Anton Flettner), maintained that a flexible two-bladed helicopter type wind turbine rotor design that is compliant with the forces of nature This type of wind turbine is more suitable for the production of standard wind turbine than rotors, which, by design, can only be constructed to resist the forces of nature. Two of Doman’s helicopters, the converted Sikorsky R-6 (Doman LZ-1A) and a Doman LZ-5 / YH-31, are on display at the New England Air Museum in Windsor Locks, Connecticut. A flexible two-bladed helicopter type wind turbine rotor design that is compliant with the forces of nature wind turbine rotors that, by design, can only be constructed to resist the forces of nature. Two of Doman’s helicopters, the converted Sikorsky R-6 (Doman LZ-1A) and a Doman LZ-5 / YH-31, are on display at the New England Air Museum in Windsor Locks, Connecticut. A flexible two-bladed helicopter type wind turbine rotor design that is compliant with the forces of nature wind turbine rotors that, by design, can only be constructed to resist the forces of nature. Two of Doman’s helicopters, the converted Sikorsky R-6 (Doman LZ-1A) and a Doman LZ-5 / YH-31, are on display at the New England Air Museum in Windsor Locks, Connecticut.

Glidden Sweet Doman, the son of Albert E. Doman and Ruth Sweet Doman, was born in Syracuse, New York, on January 28, 1921. Living in the small upstate New York village of Elbridge, Doman cam from a family of inventors and entrepreneurs . His father Albert and uncles Lewis and George Doman were the first to provide electricity for Elbridge, in 1890. Doman’s elder half-brother, Carl T. Doman, designed for Franklin Motors for Franklin and for Aircraft – including for pioneering Sikorsky VS -300 helicopter. In his teens, Doman built a series of six motorized “go carts”, and in 1936, at the age of 15, he built a Soapbox Derby racer, the first to be aerodynamically streamlined. He won the regional Soapbox Derby race held in Syracuse and held in the national championship race in Akron, Ohio. (2) (4) An attempt to build an airplane, completing much of the fuselage, but was never able to obtain an engine for it. In 1938, Doman enrolled at the University of Michigan (Ann Arbor) College of Engineering, where he majored in aeronautical engineering. While at Michigan, Doman joined and later became president of the flying club. Another member of the flying club, Joan Hamilton, Doman’s future bride, was the only female member of the club. Hamilton obtained her private pilot license and later during World War II she was invited by Jackie Cochran to join the WASP (Women Air Force Service Pilots), but she declined the offer. Doman enrolled at the University of Michigan (Ann Arbor) College of Engineering, where he majored in aeronautical engineering. While at Michigan, Doman joined and later became president of the flying club. Another member of the flying club, Joan Hamilton, Doman’s future bride, was the only female member of the club. Hamilton obtained her private pilot license and later during World War II she was invited by Jackie Cochran to join the WASP (Women Air Force Service Pilots), but she declined the offer. Doman enrolled at the University of Michigan (Ann Arbor) College of Engineering, where he majored in aeronautical engineering. While at Michigan, Doman joined and later became president of the flying club. Another member of the flying club, Joan Hamilton, Doman’s future bride, was the only female member of the club. Hamilton obtained her private pilot license and later during World War II she was invited by Jackie Cochran to join the WASP (Women Air Force Service Pilots), but she declined the offer.

Doman graduated from Michigan in June 1942, just six months after the bombing of Pearl Harbor. After his graduation, he went to work for the Ranger Aircraft Engine Division of Fairchild Aviation in Long Island, New York. Doman had some experience working with engine technologies while working at the Franklin Engine Company (where his brother Carl worked). At Ranger, Doman gained experience in using gauges to analyze the vibratory load on the rotating parts of engines. Carl Doman, who knew Igor Sikorsky from the Franklin Engineers in the Sikorsky VS-300, invited Doman to attend a meeting of Automotive Engineers meeting in New York. At this event, with Sikorsky as a featured speaker, Doman became involved in the vibratory load in helicopter rotors. As a new and unrefined invention at that time, helicopters were suffering from fatigue life. In fact, not long after Doman puts Sikorsky, a Sikorsky YR-4 had a blade fracture during a flight to the Army, which stimulated Doman’s interest all the more. In August 1943, Doman married Joan Hamilton and they immediately moved to Stamford, Connecticut where he commuted to and from work for Sikorsky in Bridgeport, CT. Doman can be found on the rotor system of a Sikorsky YR-4 to locate the weak points. He then figured out where to change the rotor system. Doman’s contributions were so vital that Igor Sikorsky himself appealed to the Navy’s Golden Navy. Doman discovered that the design of the rotor hub was the real cause of the blade failures. For the duration of World War II, he ran a program to match the blades of the Sikorsky helicopters before they were delivered. Throughout his tenure at Sikorsky, Doman was continuously learning about rotor dynamics. Doman had a very harrowing experience at Sikorsky when he was flying as a test engineer at YR-4. The pilot was slowed down by the helicopter, and it got into the so-called “vortex ring state” where the blades lose lift and the helicopter thrashes around in an almost uncontrollable fashion. Fatal crashes from such an event in the history of rotary wing aviation. In this case, however, the flying pilot has got the helicopter flying backwards, which enabled the blades to regain their lifting ability and prevent a crash. While at Sikorsky, Doman got to know Igor Sikorsky, and for years afterwards Doman Igor Sikorsky, “God takes care of helicopters.”

Together with Clinton Frazier, a mathematician and colleague at Sikorsky, Doman left Sikorsky after WW II to further develop and implement his ideas. Doman-Frazier Helicopters, Inc. was established in the autumn of 1945. The company was established in New York City, but soon moved into a barn in Stratford, Connecticut, not far from the Sikorsky plant. With financial assistance from the United States Army Air Corps, Doman obtained a surplus war R-6 Sikorsky helicopter. Doman and his engineering team modified the R-6 by creating an entirely new rotor system which featured a unique gimbaled rotor hub that was subsequently used by all Doman helicopters. After extensive successful flight testing of the modified Sikorsky R-6 (Doman LZ-1A), Doman’s team designed and built, in a joint venture with the Curtiss-Wright Corp., an all-new Doman helicopter, the CW-40. The CW-40 was followed by Doman LZ-5 / YH-31. The many innovative features in this helicopter are soon covered by numerous Doman patents. Meanwhile, after the departure of Mr. Frazier, the company was renamed Doman Helicopters, Inc. and moved to Danbury, CT. Doman Helicopters continued for nearly 20 years, building and testing several helicopters and performing other related operations to maintain the company while it attempted to establish itself as a major helicopter manufacturer. The Doman LZ-5 / YH-31 helicopters were extensively tested by the US Army and Navy. They received certification from the United States FAA, and from the equivalent Canadian authority, for sale and commercial use, after passing the rigorous tests necessary for such approvals. Doman LZ-5 / YH-31 helicopters toured the US and were well received by potential customers, especially in the oil industry along the Gulf Coast. One more toured in France and Italy performing at the Paris Air Show in 1960. Doman helicopters were a technical success but the company was unable to raise capital venture capital to full assembly line for mass production. The company ceased operations in 1969 and was legally energetic thereafter. Doman helicopters were a technical success but the company was unable to raise capital venture to full assembly line assembly for mass production. The company ceased operations in 1969 and was legally energetic thereafter. Doman helicopters were a technical success but the company was unable to raise capital venture to full assembly line assembly for mass production. The company ceased operations in 1969 and was legally energetic thereafter.

In January 1970, Doman went to work for Boeing Vertol – Boeing’s helicopter division in Philadelphia. There he continued his helicopter pioneering, working on US Army research and patenting additional design improvements for helicopter speed increases and vibration reductions. The 1973 Arab oil embargo triggered a great interest in wind energy Boeing and many other companies. While continuing his helicopter innovations, Doman began to conduct wind turbine research. He adapted computer simulation models designed for helicopters to study wind turbines. Doman and his team then built scale-model wind turbines to test them in a wind tunnel normally used for helicopters and airplanes. Doman soon understood the similarities and key differences between wind turbines and helicopters. Wind Turbine designers, but by the mid-1970s Doman had more than 30 years of such learning that was directly applicable to wind turbines. Boeing’s MOD-2 with the Doman-conceived flexible design, two-bladed wind turbine with a teeter hinge, became a flagship achievement in a 7-year NASA managed wind energy program for the US Department of Energy and the US Department of the Interior. In January 1978, Doman returned to Connecticut as Chief Systems Engineer of the wind energy program at the Hamilton Standard division of United Technologies. Drawing on Doman’s extensive knowledge of rotor dynamics for both helicopters and wind turbines, United Technologies designed and built two of the largest wind turbines ever built up to that time (ie WTS-3, WTS-4). Key features of these turbines, in addition to their size, were the use of two blades (instead of three, which is more common) and the mounting of the blades. This was analogous to Doman’s use of the gimbaled hub on his helicopters, which had 4-bladed rotors. One turbine (WTS-4) was successfully tested at Medicine Bow, Wyoming, and the other (WTS-3) in Sweden. The WTS-4 wind turbine holds the world power output record for over 20 years. Throughout all the research studies and the testing of the actual turbines, there was rapid evolution in Doman’s thinking on the best design concepts. However, when oil prices plummeted in the mid-1980s, United Technologies is the largest energy market in the world. The Italian government took notice of Doman’s work, and in July 1987, when Doman retired from United Technologies, he was hired by Aeritalia and moved to Italy to wind energy program. In this program, Doman applied his latest thinking to a new machine, largely improved over the WTS-4 and WTS-3 machines he had designed for installation in Wyoming and Sweden respectively. Under Doman’s leadership team of Italian engineers designed the Gamma 60 turbine. The Gamma 60 was the world’s first variable speed wind turbine with a teeter hinge. Three Gamma 60 turbines have been manufactured and tested for 4 years on the Mediterranean island of Sardinia. There have been intentions to build many more Gamma 60 turbines, but Italian politics and a lack of urgency due to relatively low prices in the 1990s resulted in the program being canceled. In 2003, Doman and Italian nuclear mechanical engineer Silvestro Caruso formed a new company, Gamma Ventures Inc., and bought two unused turbines, the engineering drawings, and manufacturing rights from the Italian Gamma 60 project. In 2007, Gamma Ventures sold to the Dutch company – Blue H Technologies – that was adapting offshore oil platform technology to offshore wind turbines. Blue H Technologies installed the world’s first floating offshore wind turbine in 2008 in the Southern Adriatic Sea with a two-bladed wind turbine.

Doman remained active right up to the end of his life in 2016; in the field of business, technical strategies, and analysis towards superior wind turbine performance in the application of his novel rotor technologies. He was also an avid supporter of the New England Air Museum (in Windsor Locks, Connecticut), where two of his helicopters – the converted R-6 (Doman-LZ1A) and Doman LZ-5 / YH-31 – are on display . Of the original 6 helicopter companies in the United States, Doman was the last company founder to pass away. He was one of the few helicopters to transmit rotor dynamics technology from helicopters to wind turbines. A Norwegian project announced in February 2017, involving Dr. Techn. Olav Olsen and Seawind, aims to demonstrate the wind energy applications by Glidden Doman, Anton Flettner, and Kurt Hohenemser in harsh wind and sea conditions. Doman worked through to be successful in the production of wind-generated electricity, it will be produced in great quantities, much less expensively than now, using its advanced rotor technology concepts.