Control Bar, Delta Wing Phoenix VI

Bill Bennett's Phoenix series belongs to the second generation of late twentieth century hang glider designs. It was numerous models in the second generation that helped to establish hang gliding as a legitimate sport. Bennett founded Delta Wing Kites and Gliders in 1969. He played a key role in the initial development of hang gliding in the United States when he adapted hang kites, such as his Model 162 (see NASM collection) into foot-launched hang gliders. Bennett continuously refined his designs to make them safer and to improve their performance. His work undoubtedly helped the sport to grow significantly during the 1970s.

By January 1975, Bennett, and his chief designer, Richard Boone, had completed the Phoenix IV. This variant used truncated wing tips to provide stability to the glider by enhancing the wing's tip vortices. This modification also moved the center of lift point nearer to the wingtips but away from the center of gravity, making the glider more difficult to turn and reducing stability in turbulent air. Bennett and Boone solved this problem when they introduced the Phoenix VI. They incorporated metal tubes called battens into the tips to add rigidity without reducing stability. The battens curved up slightly near the tips, adding washout and reducing the wings Angle of Attack. This reduced stall speed and helped reduce the chance that one wing tip would stall completely, a condition known to result in a flat spin. Batten tips also kept the center of lift point closer to the center of gravity, making the glider easier to control.

Gift of Bill Bennett.

Physical Description:
Metal control bar removed from A19840712000 when that artifact was removed from exhibit.

Country of Origin
United States of America

Manufacturer
Delta Wing Kites and Gliders Incorporated

Type
CRAFT-Aircraft

Materials
Metal, probably steel; plated,probably chrome; friction tape; label.

Bill Bennett's Phoenix series belongs to the second generation of late twentieth century hang glider designs. It was numerous models in the second generation that helped to establish hang gliding as a legitimate sport. Bennett founded Delta Wing Kites and Gliders in 1969. He played a key role in the initial development of hang gliding in the United States when he adapted hang kites, such as his Model 162 (see NASM collection) into foot-launched hang gliders. Bennett continuously refined his designs to make them safer and to improve their performance. His work undoubtedly helped the sport to grow significantly during the 1970s.

Before 1975, most hang gliders conformed to the standard Rogallo wing configuration. Francis Rogallo invented a flexible-wing while working for NASA during the early 1960s. This revolutionary wing could be compactly stowed like a parachute, then deployed and 'flown' with control resembling that of conventional aircraft. NASA tested the Rogallo wing and hoped to develop it into a practical spacecraft capsules recovery system. Bill Bennett discovered the Rogallo wing in 1967 and quickly developed it into a successful commercial enterprise by selling Rogallo wing kites to water skiers.

In 1973 and 1974, Bennett and his designers experimented with numerous variations of the standard Rogallo wing. Bennett then incorporated the results into a new line of hang gliders he named the Phoenix series. On these aircraft, Bennett increased the leading edge convergence angle from 80 to more than 95 degrees. The first Phoenix gliders flew with a long fantail, a device thought to improve stability. Total wing surface area was slightly less than standard Rogallo models but the aspect ratio (wingspan to wing chord ratio) increased substantially. As Bennett continued to develop the Phoenix series, he increased the leading edge convergence angle even further, and removed the fantail after flight experience showed that it did not increase stability.

By January 1975, Bennett, and his chief designer, Richard Boone, had completed the Phoenix IV. This variant used truncated wing tips to provide stability to the glider by enhancing the wing's tip vortices. This modification also moved the center of lift point nearer to the wingtips but away from the center of gravity, making the glider more difficult to turn and reducing stability in turbulent air. Bennett and Boone solved this problem when they introduced the Phoenix VI. They incorporated metal tubes called battens into the tips to add rigidity without reducing stability. The battens curved up slightly near the tips, adding washout and reducing the wings Angle of Attack. This reduced stall speed and helped reduce the chance that one wing tip would stall completely, a condition known to result in a flat spin. Batten tips also kept the center of lift point closer to the center of gravity, making the glider easier to control.

The docile handling characteristics and good stability of the Phoenix VI made it a popular trainer at hang glider flying schools. More experienced pilots also favored this model type because it flew relatively fast, had good rough air penetration and handling characteristics, and the glider could soar on updrafts far better than earlier standard Rogallo designs. This success encouraged Bennett to develop the Phoenix series further, and variations continued to appear well into the 1980s. The next variant, the Phoenix VI.B, used wing tip battens arranged in a radial pattern. This technique made the tips stiffer, reducing drag and improving roll response. The keel of the 'VI.B was shortened and Bennett added additional battens that extended all the way from the wing leading edge to the trailing edge. By tautening the wing in this way, performance improved at low and high speeds.

Towing gliders behind powerboats was initially the most common method for launching the early hang gliders, and it remained popular in areas without suitable terrain for foot- launching. The strong airframe of the Phoenix was well suited to the rigors of flight behind a powerboat and water operations required only a few modifications. A stainless-steel control bar was substituted for the aluminum version and floats were added to the ends of the control bar and at the rear tip of the keel. A towline hookup was also added.

By the mid-1980s Bennett's designs were falling behind advanced designs offered by other manufacturers and his company went out of business in 1989. Although a new generation of gliders soon overshadowed the Phoenix series, it played a key role in advancing new technologies within the hang gliding industry during the last half of the 1970s. Bill Bennett donated a Phoenix VI, configured for powerboat towing, and a VI.B along with four other Delta Wing models to the National Air and Space Museum in 1984. The flight history of this particular Phoenix VI is unknown.

Bill Bennett's Phoenix series belongs to the second generation of late twentieth century hang glider designs. It was numerous models in the second generation that helped to establish hang gliding as a legitimate sport. Bennett founded Delta Wing Kites and Gliders in 1969. He played a key role in the initial development of hang gliding in the United States when he adapted hang kites, such as his Model 162 (see NASM collection) into foot-launched hang gliders. Bennett continuously refined his designs to make them safer and to improve their performance. His work undoubtedly helped the sport to grow significantly during the 1970s.

By January 1975, Bennett, and his chief designer, Richard Boone, had completed the Phoenix IV. This variant used truncated wing tips to provide stability to the glider by enhancing the wing's tip vortices. This modification also moved the center of lift point nearer to the wingtips but away from the center of gravity, making the glider more difficult to turn and reducing stability in turbulent air. Bennett and Boone solved this problem when they introduced the Phoenix VI. They incorporated metal tubes called battens into the tips to add rigidity without reducing stability. The battens curved up slightly near the tips, adding washout and reducing the wings Angle of Attack. This reduced stall speed and helped reduce the chance that one wing tip would stall completely, a condition known to result in a flat spin. Batten tips also kept the center of lift point closer to the center of gravity, making the glider easier to control.

Gift of Bill Bennett.

Physical Description:
Metal control bar removed from A19840712000 when that artifact was removed from exhibit.

Country of Origin
United States of America

Manufacturer
Delta Wing Kites and Gliders Incorporated

Type
CRAFT-Aircraft

Materials
Metal, probably steel; plated,probably chrome; friction tape; label.

Bill Bennett's Phoenix series belongs to the second generation of late twentieth century hang glider designs. It was numerous models in the second generation that helped to establish hang gliding as a legitimate sport. Bennett founded Delta Wing Kites and Gliders in 1969. He played a key role in the initial development of hang gliding in the United States when he adapted hang kites, such as his Model 162 (see NASM collection) into foot-launched hang gliders. Bennett continuously refined his designs to make them safer and to improve their performance. His work undoubtedly helped the sport to grow significantly during the 1970s.

Before 1975, most hang gliders conformed to the standard Rogallo wing configuration. Francis Rogallo invented a flexible-wing while working for NASA during the early 1960s. This revolutionary wing could be compactly stowed like a parachute, then deployed and 'flown' with control resembling that of conventional aircraft. NASA tested the Rogallo wing and hoped to develop it into a practical spacecraft capsules recovery system. Bill Bennett discovered the Rogallo wing in 1967 and quickly developed it into a successful commercial enterprise by selling Rogallo wing kites to water skiers.

In 1973 and 1974, Bennett and his designers experimented with numerous variations of the standard Rogallo wing. Bennett then incorporated the results into a new line of hang gliders he named the Phoenix series. On these aircraft, Bennett increased the leading edge convergence angle from 80 to more than 95 degrees. The first Phoenix gliders flew with a long fantail, a device thought to improve stability. Total wing surface area was slightly less than standard Rogallo models but the aspect ratio (wingspan to wing chord ratio) increased substantially. As Bennett continued to develop the Phoenix series, he increased the leading edge convergence angle even further, and removed the fantail after flight experience showed that it did not increase stability.

By January 1975, Bennett, and his chief designer, Richard Boone, had completed the Phoenix IV. This variant used truncated wing tips to provide stability to the glider by enhancing the wing's tip vortices. This modification also moved the center of lift point nearer to the wingtips but away from the center of gravity, making the glider more difficult to turn and reducing stability in turbulent air. Bennett and Boone solved this problem when they introduced the Phoenix VI. They incorporated metal tubes called battens into the tips to add rigidity without reducing stability. The battens curved up slightly near the tips, adding washout and reducing the wings Angle of Attack. This reduced stall speed and helped reduce the chance that one wing tip would stall completely, a condition known to result in a flat spin. Batten tips also kept the center of lift point closer to the center of gravity, making the glider easier to control.

The docile handling characteristics and good stability of the Phoenix VI made it a popular trainer at hang glider flying schools. More experienced pilots also favored this model type because it flew relatively fast, had good rough air penetration and handling characteristics, and the glider could soar on updrafts far better than earlier standard Rogallo designs. This success encouraged Bennett to develop the Phoenix series further, and variations continued to appear well into the 1980s. The next variant, the Phoenix VI.B, used wing tip battens arranged in a radial pattern. This technique made the tips stiffer, reducing drag and improving roll response. The keel of the 'VI.B was shortened and Bennett added additional battens that extended all the way from the wing leading edge to the trailing edge. By tautening the wing in this way, performance improved at low and high speeds.

Towing gliders behind powerboats was initially the most common method for launching the early hang gliders, and it remained popular in areas without suitable terrain for foot- launching. The strong airframe of the Phoenix was well suited to the rigors of flight behind a powerboat and water operations required only a few modifications. A stainless-steel control bar was substituted for the aluminum version and floats were added to the ends of the control bar and at the rear tip of the keel. A towline hookup was also added.

By the mid-1980s Bennett's designs were falling behind advanced designs offered by other manufacturers and his company went out of business in 1989. Although a new generation of gliders soon overshadowed the Phoenix series, it played a key role in advancing new technologies within the hang gliding industry during the last half of the 1970s. Bill Bennett donated a Phoenix VI, configured for powerboat towing, and a VI.B along with four other Delta Wing models to the National Air and Space Museum in 1984. The flight history of this particular Phoenix VI is unknown.

ID: A19840712002