A short history of the east coast U.S. hang glider manufacturer Sky Sports, by Lootenant Aloominum, June 2016, including photos and info from Chris Gonzales and Robert W Cordier
He’s got the church and the palace of Westminster on his side. Who have you got?”
“My mum. She thinks I’m a genius.”
— from a dialog in The Sweeney, a popular 1970s UK television series about a fictionalised Metropolitan Police ‘flying squad’
Most of the images on this page are artistic derivations of contemporary photos.
Sky Sports was a hang glider manufacturer based originally near Boston, and then in Ellington, Connecticut, New England, north of New York. At least some of their sails were made by Odyssey Sails of Wilton, New Hampshire. The flying in New England is arguably more demanding than in California, where most hang glider manufacturers were based, because of the wind and rain. A bit like where I (the original author of this web site) live in old England, by the sound of it. However, unlike old England, the flying regions of New England are largely tree-covered, with ‘tree slot’ launches and tight landing areas.
While some trained aeronautical engineers made great contributions to early hang glider development, on the whole they did not build better hang gliders than those who were self taught (whose mums doubtless thought they were geniuses). As far as I know, Sky Sports originally relied on designs by hang gliding pioneer Tom Peghiny, whose early work included a ‘cylindrical’ Rogallo wing with highly curved leading edges. (For photographs, see Cylindrical Rogallo in Rogallo wing definitions and diagrams.) His later work included a monoplane with a V-tail, which was nevertheless weight-shift controlled, like conventional Rogallo wings.
Stepping back four years from the 1978 Sirocco…
Dan Poynter of north Quincy, Massachusetts, wrote the first widely read authoritative book on the subject; Hang Gliding, the Basic Handbook of Skysurfing. LARK is an acronym for Low Aspect Ratio Kite.
For an experimental wing that is claimed to be based on the LARK, see Cylindrical Rogallo in Rogallo wing definitions and diagrams.
The Bobcat was designed to be easier to fly than their contemporary higher-performance wings.
In this photo, either the bird art had not yet been applied to the sail or it is a different glider from that in subsequent photos.
See under External links later on this page for film of Tom flying at this event.
The Bobcat 2 featured three battens each side, each at a different angle, to support the slight roach cut of the sail near the tips.
While Wills Wing in California improved the performance and handling of the Rogallo with the Swallowtail design, Sky Sports on the east coast went in a different direction, the result being the Kestrel. (It has no connection with Kestrel Kites of Dorset, old England.)
The pilot of the wing on the left is aerodynamicist Bill Figuerido and the other pilot is Tom Peghiny. The original photo is by W.A. Allen.
Here is a picture in words by Chris Gonzales, who flew a Kestrel B while his Sirocco II (see farther on) was being built:
When I started at Barber’s Hill, it was lush with Kestrel Bs, a string of them slowly advancing in stages up the path on the 200-foot hill. They glided flat and long, landing deep into a far hayfield.
This screenshot from the Pico Peak 1978 competition film is annotated by Chris Gonzales to identify Sky Sports wings set up, presumably, near the landing strip.
Chris says of the Kestrel B, “Amazing glider for its simplicity (three straight metal curtain rod battens per side and a curved nose batten).”
Incidentally, for a newer photo of the Sirocco 1 in the screenshot, see farther on.
The Osprey was a popular intermediate-level wing.
Eventually, Tom Peghiny was joined by another self-taught hang glider designer, Terry Sweeney, an electronics technician (self taught in that too) working in the field of radar jamming electronics for the military. Together, they created the Sirocco, one of the first double-surface flex-wing hang gliders.
Notice the shape of the sail of the Sirocco in the accompanying screenshot from the Francis Freedland documentary film 1978 Pico Peak International Hang Gliding Meet (see my review, linked farther down). The inboard battens were secured in position with cables to the control frame corners and (apparently) to the top of the king post. The sail was thereby kept from applying upward (or in the event of severe misfortune, downward) force on the crosstubes. (Nowadays they build the crosstubes strong enough to take any additional bending forces imparted by the sail.) Those wires arguably also improved the span-wise twist distribution of the wing.
Incidentally, the pilot in the screenshot is flying in a seat harness inside the control frame.
This Sirocco 1 originally belonged to Chris Gonzales’ instructor, Mike McCarron. It is the actual same one in Chris’s annotated screenshot farther up this page.
Double surface wings enclose the cross-tubes between the upper and lower surfaces of the sail, which eliminates the aerodynamic drag of the crosstubes. This photo also shows deflexor cables cluttering the leading edges. They added strength and kept the lanky tubes from distorting out of shape. However, those deflexors also created a lot of drag, increased the cost of manufacture, and increased the time you spent rigging and de-rigging your wing. Modern hang gliders do not have them. Nevertheless, they provided an ability to fine-tune a glider’s handling:
I was able to optimize for steep turns, say 60 degrees, the kind of turn you would use in a strong thermal core. With careful tuning, I could set up up a sweet spot within which the glider really coordinated well in that bank and climbed extraordinarily well.
— Chris Gonzales
Sweeney worried about the lack of pitch stability of the standard Rogallo in a dive, as many of us did. According to reports, at zero angle of attack, the sail ‘luffed’ (flapped uselessly) and created no lift to shift your weight relative to, so you were unable to pull out of the dive. (See Luff in the time of cholera about that phenomenon.) Given enough height, the drag of the flapping sail would — in theory — pull you out, but we rarely gained enough height for that in those days. In 1973, Sweeney added a strut under the sail near each wingtip, with a cable to the top of the king post that limited the strut’s downward arc about its attachment to the leading edge. In an extreme dive, it acted as an up-elevator. It was a combined dive strut and reflex bridle, as we would understand it today.
The Sirocco II, which was Sweeney’s own project with input from Sky Sports test pilots, had six battens per side, as compared with the original Sirocco’s five per side. The Sirocco II also had a wider nose angle and more area at the tips. Chris Gonzales describes it as a “great design.”
One of the pilots who contributed to the design of the Sirocco II was 1978 US champion and author of a series of technical articles in the magazine, which eventually he turned into reference books, Dennis Pagen.
This photo shows the cable from the control frame corner to the inner-most batten, reducing washout at the root.
Bear in mind that the personal computer was still years away. Unless you had links with academia or, like Barry Hill Palmer, you worked in California aerospace, in which case you might obtain time on a mainframe computer, you either used a slide rule to aid hand-written calculations or you used a programmable calculator to help design your wings. If you were a bit outside the box, you used a Hewlett Packard reverse Polish notation calculator, which did not even have an equals = key! (For Barry Hill Palmer’s use of a mainframe computer in designing his first hang glider — this was in the early 1960s — see Early powered ultralights.)
Terry Sweeney’s hang glider design program, which he used on the Sirocco project, contained 224 steps. However… “We still sort of handle the shapes intuitively — the nose angles and the sweeps, and the anhedral/dihedral tuning, and stuff.”
Nevertheless, hang gliding was (and is) not just a by-product of the space age or of developments in computing. As Chris Gonzales points out: “Of course, hang gliders owed much to sailboat design and technology. The art of sail making and time-tested hardware allowed designs to advance quickly.”
A further use for the computer is in generating airfoils. The Sirocco II exhibits a higher mean camber in the root section in a rearward moving high point away from the root. This again helps prevent tip stalls by evening out the lift distribution.
— Dennis Pagen in Hang Gliding, May 1978
The DECSYSTEM-20 is the cabinet at the back (with the ‘terracotta’ burnt orange horizontal stripe). We had one where I (the original author of this web site) studied computing in the late 1970s. I attempted to write a Rogallo hang glider stress analysis program on it, which I never finished, in Fortran 4.
Boy, things happened fast in those days. They were literally designing faster than the magazine could report on them!
— Chris Gonzales
For the next phase in the use of computing in hang glider design, manufacture, and distribution, see under From our house to bunkhaus in Hang gliding early 1980s part 2.
A prominent pilot, who wants to remain anonymous, provided information and contact details of some potential and actual contributors.
Bob Cordier provided photos via FaceBook Messenger.
Chris Gonzales sent me info and photos by e-mail. In addition, I added more snippets from his subsequent article, Sky Sports Gliders of the Late ’70s, published in the USHPA magazine Hang Gliding & Paragliding, September/October 2017 (linked later on this page).
Sky Sports was originally (in about 1972) based out of Ted Strong’s parachute loft near Boston, according to Dan Chapman writing in Aerie, the Hang Gliding Magazine (an independent east coast oriented publication) May 1976. Sky Sports subsequently moved to Ellington, Connecticut, according to their advert in Hang Gliding, August, 1977.
Details of the hang glider development process, including the use of programmable calculators, is from an interview with Terry Sweeney by Bill Allen, published in Hang Gliding magazine, August 1977. In addition, in about 1980, I used a desk-top programmable calculator at work (radar jamming electronics, same as Terry Sweeney).
Graeme Bird’s hang gliders, the New Zealand sail-maker’s work that advanced the state of the art
Mid-day lightning in Vermont, my review of the Francis Freedland documentary film 1978 Pico Peak International Hang Gliding Meet
Skyhook Sailwings, a short history of the early hang glider and powered ultralight manufacturer based in the north of England
Big Blue Sky — The history of modern hang gliding – the first extreme sport! by Bill Liscomb on YouTube. The link starts at 2 minutes and 41 seconds, where Terry Sweeney flies an early biplane hang glider. Narration of that segment is by Bob Trampenau of Seedwings.
For a remarkable photo of the Sky Sports Sirocco, see this Oz Report forum post. On a Windows computer, right-click the partial image and select Open image in new tab or View image (or your browser’s equivalent) from the shortcut menu.
For photos of another artistically painted Sirocco, see this post on hanggliding.org.
Hang Ten Hang Gliding World Meet, Part 2 (1974) video on YouTube starting at 3 minutes 54 seconds, where Tom Peghiny makes his speed run in a Sky Sports Merlin
Hang Ten Hang Gliding World Meet, Part 3 video on YouTube starting at 4 minutes 5 seconds, where Paul Courtney performs an ‘aerial bellet’ (a required competition task in those times) in a Sky Sports Merlin. (The video also starts with Courtney flying an earlier task.)
Kestrel, I am fairly sure, launching: 1976 Kössen 1 de 3 15 min digitized film on YouTube by Roman Camps taken at the second world championship, Kössen, Austria, in 1976, starting at 11 minutes 40 seconds
Sirocco launching and flying: 1976 Kössen 1 de 3 15 min digitized film on YouTube by Roman Camps taken at the second world championship, Kössen, Austria, in 1976, starting at 8 minutes 13 seconds
Sky Sports Gliders of the Late ’70s by Chris Gonzales with photos by Tina Sheppard in Hang Gliding & Paragliding Vol47-Iss5 Sep-Oct 2017
Tom Peghiny flying the Sky Sports Bobcat and landing on the target carved on the sand in Soaring and Gliding Festivals 1973-1974, a digitized ‘Super 8’ (8 millimetre) film on YouTube by John Elwell. Filmed at Elberta dunes, Michigan, in 1974 starting at 26 minutes 29 seconds
Tom Peghiny flying again, starting at 39 minutes 47 seconds