Hang gliding 1975 part 2


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Hang gliding 1975 part 2

This page continues from Hang gliding 1975 part 1.

Still from 'Sky Riders,' 1976

Chris Wills demonstrates the Wills Wing Swallowtail’s resistance to the luffing dive

For more about the luffing dive, see Luff in the time of cholera. (Sorry!)


The highest scoring pilot at the 1975 British Championships was American Bob Wills flying an all-black Sport Kites Inc. Wills Wing Swallowtail. Examining the glider from under its expanse of sailcloth I noticed that the sun highlighted brownish streaks criss-crossing the fabric. Wills explained that the sails of these gliders were originally white (or multicolored in some cases) and they were painted black for an upcoming movie which they had just filmed in Greece. The film was Sky Riders, starring James Coburn, Susannah York, Robert Culp, and Charles Aznavour. It was in cinemas/movie theaters the following year. See Paint it black–my review of that film. For my involvement in the British championship competition, see under Riders in the sky in Simple versus complex (my flying 1975 part 2).

Hang gliding in 'Sky Riders,' 1976

Paint it black

While most hang glider pilots flew standard Rogallos in 1975, in the USA several people attempted to improve on the basic idea. One was the Wills Wing Swallowtail with its reduced billow, cut-out trailing edge, and (in later versions) tip roach supported by radial battens. Other engineers tried different approaches to achieving improved performance.

See also my threads page Sport Kites/Wills Wing of California.

Cirrus

Art based on a photo by Russ Stolling of Larry Newman in the Electra Flyer Cirrus at Telluride, Colorado

Art based on a photo by Russ Stolling of Larry Newman in the Electra Flyer Cirrus at Telluride, Colorado

The Cirrus was actually the Windlord 4 created by Rich Finley. Like most Rogallos, it had no sail battens.

Art based on a photo of the Electra Flyer Cirrus with battens added

Electra Flyer Cirrus with battens added

Chord-wise battens took extra time to rig and de-rig, but they reduced aerodynamic drag caused by sail flutter. This is the production Electra Flyer Cirrus.

For more about the Cirrus series, see my threads page Electra Flyer of Albuquerque, New Mexico.

Kestrel

Art based on a photo by Bettina Gray of Tom Peghiny flying a Sky Sports Kestrel hang glider at Mt. Cranmore, New England, in early 1975

Art based on a photo by Bettina Gray of Tom Peghiny flying a Sky Sports Kestrel at Mt. Cranmore, New England, in early 1975

See my page Flying squad for a short history of the east coast U.S. hang glider manufacturer Sky Sports.

Dragonfly

Nineteen year-old Roy Haggard designed, built, and flew the Dragonfly. When Pete Brock of Ultralight Products saw it perform at the 1974 U.S. nationals, he agreed to manufacture it.

Roy designed the ubiquitous Dragonfly, test-flying it for the first time on October 27, 1974. He surprised everyone (maybe “shocked” is a better word for it) when he appeared out of the obscurity of Visalia, Calif., as a relative unknown to come in a strong 7th at the 1974 U.S. Nationals… and with such a weird-looking design.

— Rich Grigsby (I assume) writing in Ground Skimmer, June 1976

Art based on a photo by Leroy Grannis of Charles Baughman and Roy Haggard over ‘the domes’ site at Palos Verdes, California

As I understand it, Charlie Baughman obtained Roy Haggard’s prototype, so it is likely that he is flying it (the lower one, white and red, relatively scruffy) in the photo and Roy Haggard is flying the upper example (with an aerodynamically cleaner orange sail) made by Ultralight Products.

The handling of the Dragonfly embodied a yaw characteristic that imparted a uniquely graceful motion in the air. Apparently always under perfect control, yet always curving to the right or left…

After the truncated wing tips, there still was 20 feet of leading edge, while the keel was only 11 feet long. And yet, his and the other two designs all responded amazingly well to weight shift control.

— W.A. Allen describing Roy Haggard’s Dragonfly at the 1974 US nationals in Wings Unlimited, February-March 1975

One of the other two designs that Bill Allen refers to is Rich Finley’s short-keel, low billow, and spiky-looking Windlord IV.

British hang glider manufacturer Birdman, of Marlborough in Wiltshire, brought two (I think) Dragonflies and a Red Tail (Ultralight Products’ easier to fly wing) from the 1975 world championships at Kössen, Austria, back to Britain. I saw the Dragonflies flying at Mere in Wiltshire in the summer of 1975. The yaw characteristic of those gliders imparted a uniquely graceful dynamic in their flight. I assume that Birdman intended to build the Dragonfly under licence, but my information is that they did not do so. However, they took on board UP’s slick hardware and the entire Birdman range was soon unequaled in quality of finish and slickness of fittings. I am told that the late Pat Fry, who I had flown with on occasion, obtained a Dragonfly, but his one flight in it scared him so badly he never flew it again.

Art based on a photo by Ultralight Products of an early Dragonfly launching at Waimanalo, Hawaii

Art based on a photo by Ultralight Products of an early Dragonfly launching at Waimanalo, Hawaii

In the Hawaii image, notice other hang gliders specking out behind the Dragonfly.

See my threads page Ultralight Products of California and Utah.

Nova

Painting of an early hang glider

The Wasp Nova of 1975 (painting)

The 1975 Wasp Nova was another attempt at attaining more performance without too much extra complexity. It featured an S-curved keel tube and tip fins braced by tubes, brackets, fasteners, and cables. I saw the prototype before it flew when it was on display at the inaugural meeting of the BHGA on December 8th, 1974, at the Matrix Hall in Coventry. (It had two unfinished top rigging wires with ends dangling, yet to be cut to length and swaged.)

There are photos of the Nova linked from my threads page Waspair of Surrey, England.

Prone

Photo of a standard Rogallo hang glider in flight

The prone harness imparted a dramatic increase in performance and pitch control. Photo by Dave L.

The prone harness imparted a dramatic increase in performance and pitch control. That combined advantage greatly improved our ability to soar.

Because your angle of bank in a coordinated turn is limited by the positive (nose-up) pitch rate you can achieve, and the seated flying position conferred very little pitch range, we could only fly shallow turns without the turn degenerating into an inefficient spiral descent. The prone flying position enables the pilot to ‘push out’ and thereby coordinate a steeper banked and tighter turn. That was important for flying in thermals, which we began to do (unwittingly at first) in the long dry summer of 1976 in southern England.

As far as I know, Hiway Hang Gliders of Brighton in Sussex were the first in Britain to manufacture prone harnesses. The glider in the preceding photo by Dave L is a Hiway standard Rogallo. (See my threads page Hiway of Sussex, England, and Abergavenny, Wales.)

Donnita

Art based on a photo of Donnita Holland (Donnita Hall) in 1975

Art based on a photo by W.A. Allen of Donnita Holland (Donnita Hall) in 1972 or 1973

Donnita Holland was the first female to pilot a hang glider, one of the first humans to foot-launch a hang glider, and one of the pioneers who showed the rest of the world how to follow their dreams. She worked as a secretary at Hewlett Packard, where she met Dave Kilbourne, who was one of the first to fly a Rogallo hang glider, initially launching on water skis while towed behind a power boat. (1)

Donnita in about 2007. Screenshot from Big Blue Sky by Bill Liscomb.

Donnita in about 2007. Screenshot from Big Blue Sky by Bill Liscomb.

Art based on a photo of Donnita Holland flying her own design standard Rogallo

Art based on a photo of Donnita Holland flying her own design Rogallo wing (no larger image available)

She built a wing of her own design in 1976. It had 17-foot long leading edges and a 13-foot keel. The sail was built by Albatross (led by sailmaker and aeronautical engineer Tom Price) of Southern California. (2) In the picture, you might be able to make out the truncated tips, more aerodynamic than those of the Dragonfly, and side flying struts instead of wires. They obviated the need for top rigging with its attendant drag, cost, weight, and set-up time.

Many of the very early Rogallos were strut braced (with bamboo poles) but even before the advent of top rigging, cable bracing became the norm. Nonetheless, following Donnita’s lead, Seagull Aircraft made a strut-braced version of their 10 Meter, designed by Tom Peghiny and Bob Keeler, the following year. (3, 4)

Donnita’s aeronautical engineering talents were well in advance of most others at the time, yet she was content to let her partner Dave Kilbourne receive the lion’s share of the publicity, mainly for his daring flying achievements. I guess the media understood heights and distances better than they understood the technology.

For more about Donnita, see under External links later on this page.

Gulp

…the late, great low-speed aerodynamicist, Dr. Paul MacCready, once told me that he felt the hang gliding design evolution had progressed further through a semi-educated trial-and-error process than what would have been achieved in the same time span by classically educated aerodynamicists.

— Lt. Col. Mark Stucky USMC (call sign Forger) in Hang Gliding & Paragliding, January 2008

While the Rogallo offered the advantage of simplicity, its one-piece airfoil (two, if you regard both halves as separate) that combined the functions of generating lift and providing control and stability, compromised those individual needs heavily. Conventional aircraft, including gliders (sailplanes) employ separate wing and tail surfaces to provide those separate functions. That results in greater efficiency, but at the cost of complexity. Several designers created hang gliders with separate wing and tail surfaces. Some were entirely rigid, with conventional control surfaces, while others used sailcloth with a some airframe flexibility in an attempt to retain the simplicity of pilot weight shift as the control method. Foremost among practitioners of the latter, in Britain at least, was Miles Handley. His first glider, which owed almost nothing to any predecessor, was the Gulp.

Miles Wings Gulp flight test in 1975

Miles Wings Gulp flight test in 1975

I seem to recall that this photo of the Gulp, which its designer and constructor Miles Handley (who had no formal education in aerodynamics) sent me as a print, was of the second flight of the prototype.

Technical: The original Miles Wings Gulp had no battens, but — extraordinarily — the thick sailcloth maintained an airfoil section, as if by magic, even when the wing was rigged flat on the ground. It had just enough dihedral (and the sail was cut precisely) that span-wise tension together with the curved join of the two semi-spans at the root ensured its 3-D form. In the photo of a Gulp rigged at Mere, Wiltshire, in 1976 (linked farther on) notice how the sail holds its shape with no battens and no wind. Nevertheless, the Gulp was reputed to be hard to turn, a problem likely magnified by that dihedral.

Technical: I heard also that it suffered from a minor pitch control problem (a phugoid) because the changed airflow at different pitch angles (so-called angle of attack) caused the high point of the airfoil curve to move forward and back, countering the pilot’s control inputs. To resolve that problem (which struck my own later experimental glider more seriously) the next version of the Gulp featured chord-wise airfoil shaped fixed battens spaced evenly across its entire span.

Brian Wood flying a Miles Wings Gulp 130

Brian Wood flying a Miles Wings Gulp 130

Brian Wood, the first British hang gliding champion, did not do as well as expected in the 1975 competition, but he demonstrated the Miles Wings Gulp 130 monoplane flex-wing one calm evening. Having launched from the ridge top, instead of gliding down to land at the bottom like every other hang glider, he flew straight out, losing barely any height until he touched down in a field far out from launch.

Meanwhile, both Bob Wills in California and Miles Handley in Britain were working on new developments, one an extension of previous design improvements and the other so radical it took a few years to come to fruition.

See my threads pages Miles Wings Gulp and Gryphon and Sport Kites/Wills Wing of California.

More developments

Art based on a photo of a Wills Wing SST in The Book of Airsports by Ann Welch

Art based on a photo from ‘The Book of Airsports’ by Ann Welch of the next development by Wills Wing

Art based on a photo by Bettina Gray of an Eipper Cumulus VII

Art based on a photo by Bettina Gray of an Eipper Cumulus VII


And other manufacturers forged ahead combining short root chord, fixed tips, and battens. The Cumulus VII was made by Dick Eipper’s company Eipper Formance Inc. (Say it out loud…)

This topic continues in Hang gliding 1976 part 1.

External links

Big Blue SkyThe history of modern hang gliding – the first extreme sport! by Bill Liscomb on YouTube

Donnita: From Toys to Wings… by C.J. Sturtevant in Hang Gliding & Paragliding Vol48-Iss1 Jan-Feb 2018

“First Lady” of Hang Gliding, Donnita Hall in Big Blue Sky by Bill Liscomb on YouTube starting at 31 minutes 45 seconds

Mere Wiltshire BHGA photos by Don Liddard on flickr, including some taken at the 1975 British championship competition

Photo by Roger Middleton of gliders in line for launch at the British championships, held at Mere in Wiltshire in August 1975

References

1: An Evening with Dave Kilbourne and Donnita Holland by W.A. Allen in Ground Skimmer, September 1973

2: Hang Gliding and Paragliding October 2007

3: Bill Allen, Hang Gliding, July 1977

4: Dennis Pagen, Hang Gliding, February 1994