Delta Wing Phoenix VI B Jr.

In 1973 and 1974, Bill Bennett and his hang glider 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 gliders, Bennett increased the leading edge convergence angle from 80 to more than 95 degrees. The first Phoenix hang 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.

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. In the next variant, the Phoenix VI.B, Bennett and Boone added 'deflexor' cables mounted on the wing leading edges to stiffen and carefully curve the wing for better flying performance and increased stability. During assembly at the factory, technicians rigged and tuned the glider to fly with a tendency to pitch up in high-speed flight. This built-in auto-recovery mode was aimed at helping pilots recover safely from high-speed dives. The VI.B also 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.

Gift of Bill Bennett.

Physical Description:
White / light blue / purple / dark blue sail; without harness or cover bag; 18ft. 5 1/2in. leading edge long; aluminum and dacron; 1974.

Country of Origin
United States of America

Manufacturer
Delta Wing Kites and Gliders Incorporated

Location
Steven F. Udvar-Hazy Center, Chantilly, VA
Hangar
Boeing Aviation Hangar

Type
CRAFT-Aircraft

Dimensions
Wingspan: 9 m (29 ft 5 in)
Length: 2.7 m (9 ft)
Weights: Empty, 19 kg (41 lb)
Gross, 109 kg (241 lb)

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 capsule 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 gliders, Bennett increased the leading edge convergence angle from 80 to more than 95 degrees. The first Phoenix hang 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. In the next variant, the Phoenix VI.B, Bennett and Boone added 'deflexor' cables mounted on the wing leading edges to stiffen and carefully curve the wing for better flying performance and increased stability. During assembly at the factory, technicians rigged and tuned the glider to fly with a tendency to pitch up in high-speed flight. This built-in auto-recovery mode was aimed at helping pilots recover safely from high-speed dives. The VI.B also 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.

Bennett offered the Phoenix VI.B in three sizes, the Junior, the Standard, and the Senior. Pilot weight range dictated the designations. The Junior was intended for those who weighed from 63.5 - 90.7 kg (140 - 200 lb), the Standard was designed for the 68 - 95.3 kg (150 - 210 lb) weight range, and the Senior for pilots weighing 72.6 - 108.9 kg (160 - 240 lb).

Beginning in the mid-1970s, many hang glider enthusiasts began to focus on setting cross-country flying records. The technological innovations that Bennett and Boone designed into the Phoenix VI.B made it ideal for flights in varying wind conditions. The deflexor cables and battens made the wing stiff enough to penetrate well through rough air. Phoenix pilots set several world distance and altitude records.

By the mid-1980s, Bennett's aircraft were failing to keep pace with innovative gliders built by other companies and Delta Wing Kites and Gliders folded permanently in 1989. Bill Bennett donated a Phoenix VI and a VI.B Jr., along with four other Delta Wing hang gliders to the National Air and Space Museum in 1984. The flight history of this particular Phoenix VI.B Jr. is not known.

In 1973 and 1974, Bill Bennett and his hang glider 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 gliders, Bennett increased the leading edge convergence angle from 80 to more than 95 degrees. The first Phoenix hang 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.

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. In the next variant, the Phoenix VI.B, Bennett and Boone added 'deflexor' cables mounted on the wing leading edges to stiffen and carefully curve the wing for better flying performance and increased stability. During assembly at the factory, technicians rigged and tuned the glider to fly with a tendency to pitch up in high-speed flight. This built-in auto-recovery mode was aimed at helping pilots recover safely from high-speed dives. The VI.B also 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.

Gift of Bill Bennett.

Physical Description:
White / light blue / purple / dark blue sail; without harness or cover bag; 18ft. 5 1/2in. leading edge long; aluminum and dacron; 1974.

Country of Origin
United States of America

Manufacturer
Delta Wing Kites and Gliders Incorporated

Location
Steven F. Udvar-Hazy Center, Chantilly, VA
Hangar
Boeing Aviation Hangar

Type
CRAFT-Aircraft

Dimensions
Wingspan: 9 m (29 ft 5 in)
Length: 2.7 m (9 ft)
Weights: Empty, 19 kg (41 lb)
Gross, 109 kg (241 lb)

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 capsule 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 gliders, Bennett increased the leading edge convergence angle from 80 to more than 95 degrees. The first Phoenix hang 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. In the next variant, the Phoenix VI.B, Bennett and Boone added 'deflexor' cables mounted on the wing leading edges to stiffen and carefully curve the wing for better flying performance and increased stability. During assembly at the factory, technicians rigged and tuned the glider to fly with a tendency to pitch up in high-speed flight. This built-in auto-recovery mode was aimed at helping pilots recover safely from high-speed dives. The VI.B also 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.

Bennett offered the Phoenix VI.B in three sizes, the Junior, the Standard, and the Senior. Pilot weight range dictated the designations. The Junior was intended for those who weighed from 63.5 - 90.7 kg (140 - 200 lb), the Standard was designed for the 68 - 95.3 kg (150 - 210 lb) weight range, and the Senior for pilots weighing 72.6 - 108.9 kg (160 - 240 lb).

Beginning in the mid-1970s, many hang glider enthusiasts began to focus on setting cross-country flying records. The technological innovations that Bennett and Boone designed into the Phoenix VI.B made it ideal for flights in varying wind conditions. The deflexor cables and battens made the wing stiff enough to penetrate well through rough air. Phoenix pilots set several world distance and altitude records.

By the mid-1980s, Bennett's aircraft were failing to keep pace with innovative gliders built by other companies and Delta Wing Kites and Gliders folded permanently in 1989. Bill Bennett donated a Phoenix VI and a VI.B Jr., along with four other Delta Wing hang gliders to the National Air and Space Museum in 1984. The flight history of this particular Phoenix VI.B Jr. is not known.

ID: A19840715000