Spectra Aolus


Home (contents) Hang gliding early 1980s part 1 Spectra Aolus

Spectra Aolus

It was a superb thermalling machine. In a strong, smooth core, you could push out past stall and flat-spin at 2000 fpm. Unique and unbelievable. With that reflexed tail, it gave you a very secure feeling that it would recover from going over the falls in violent thermals.

— Rick Masters (1)

Carlos Miralles with a Spectra Aircraft Corporation Zodiac (left, and two Aoli hang gliders
Carlos Miralles with a Zodiac (left) and two Aoli. Photo by Carlos’ brother Mario. (2)

In 1980, the Spectra Aircraft Corporation (of Concord, California) offered hang glider pilots a radical looking new wing: The Aolus. It had its roots in the popular curved leading edge Seagull 3.

John Reisig started out assembling kits of the Seagull III and selling them. (That might sound trivial, but in this author’s experience, assembling hang gider kits was not as straight-forward as it should be. And, although I was an ‘agent’ in my area for a leading hang glider manufacture in Britain, I did not sell a single one!) Seagull eventually stopped supplying Reisig with kits. Trading as Suspended Animation, he then manufactured Seagull III clones, adding refinements that improved on the original. (3)

Aero engineering student Carlos Miralles designed a new sail for John Reisig’s curved leading edge frame. It incorporated battens, wide chord fixed tips, and anti-dive tip struts (the latter much as are still used in 2020). It went into production as the Zodiac (nearest wing in the main photo) which superficially resembled to the Seagull ‘Ten Meter.’

Spectra Aolus hang glider advert of 1981
Aolus advert

At weekends Bill Dodson drove from Cal Poly at San Luis Obispo, where both he and Carlos Miralles were students, to John Reisig’s shop in the San Francisco area. There, Dodson and Miralles created a series of prototype advanced hang gliders, culminating in the Aolus.

Because the thimbles on the nose wires eventually flattened out and the cable got longer, we had to make the cables short and do some hard wangs on the first flight to “set” the tangs before shipping a customer…

— Hang glider designer Bill Dodson

However, the Ultralight Products Comet and its clones, which finally incorporated a double surface sail that enclosed the cross-tubes — and did so without critical drawbacks — soon dominated the hang gliding scene. Bowsprit-rigged wings such as the Aolus had too many external cables that created drag when flying fast and they were unable to compete with the Comet.

We tried pushing the Aolus planform to its performance limits by building versions with a large amount of double surface and an enclosed crossbar. While prototypes flew very well at cool beach sites, the design turned out to have unusually high sensitivity to temperature due to its low sweep. A glider tuned to fly at the cool beach ended up being unmanageable at hot inland sites due to differences in sail tension as the tubes expanded in the heat.

— Bill Dodson

Flexiform Sealander hang glider
Flexiform Sealander of 1981

The British Flexiform Sealander closely resembled the Aolus. The first reference to it that this author has found is in the February 1981 edition of the British hang gliding magazine.

Hiway Alien hang glider
Hiway Alien of 1982

Another British design with a similar tail, but with flexible curved tips as used on many flex-wing hang gliders in the 21st century (2020) was the Hiway Alien of 1982. However, the Alien — unlike the Aolus and the Sealander — never reached production status.

Together with the Gannet, the Sigma, and the Sealander, the Aolus was the last of the bowsprit-rigged high performance hang gliders. However, the bowsprit-rigged general arrangement lived on in a line of gliders made by Bautek of Germany. Light in weight and with nimble handling and excellent sink rates, they continued to be made until Bautek closed in early 2020. The bowsprit configuration additionally confers the safety advantage that, in the event of a ‘nose-in’, the pilot cannot be struck on the back of he head by the nose of the glider, which is a danger of some other types of hang glider.

One of the Aolus designers applied for a job with a major airplane manufacturer and the aerodynamicist interviewer asked mostly questions about his hang glider design expertise and knowledge. That was the experience they were looking for in designing a secret flying wing.(3) I assume some of his subsequent design projects might still be classified, but it is safe to say here that one was a supersonic stealth fighter. (Two prototypes flew, but it was eventually rejected by the U.S. Air Force.) Another holds world records (standing in 2020) for combat mission length and duration. See also American bomber in Mitchell Wing.

Related

Flex-wings with tails related topics menu

Gannet: Hang gliding early 1980s part 1

Hiway Alien: Hiway of Sussex, England, and Abergavenny, Wales related topics menu

Lightnings, Comet clones and pod people in Hang gliding early 1980s part 1

Seagull III and Seagull Ten Meter: Seagull Aircraft of Santa Monica, California related topics menu

Sigma: South downs in Hang gliding early 1980s part 1

Ultralight Products Comet: American revolution in Hang gliding 1978 and 1979 part 3

External link

Aoli, Comet Clones & Pod People: Rick Masters’ page about flying and competing in the Owens Valley, California

References

1. Rick Masters: Dangerous Thoughts on US Hawks forum (scroll to subtitle The Aolus Boogie)

2. Mario cummunication to the author in November 2020

3. Post by wingsmith (Bill Dodson) on Hanggliding.org forum, Sun Dec 11, 2011 2:36 am

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