John Dickenson flying the Mark 3 version of his wing. Grafton, Australia 1965. The Dickenson wing and the pendulum, weight-shift control system is an aircraft design that has not only been used for perhaps 90% of all hang gliders made since, it is also the basis from which the aircraft known as 'trikes' in Australia have been developed. Unfortunately there has been little recognition, in Australia and internationally, of the enormous contribution made by John Dickenson's wing and the pendulum weight-shift control system.

CAB Wasp: designed by Neville White in 1978 after purchasing a Scout which he found unsuitable. He built sixteen of the aluminium tube and sailcloth CAB Wasps. Neville — honoured as a Pioneer by RA-Aus in 2008 — is a member of the Holbrook Ultralight Club. Photo courtesy of Max Brown of the Australian Ultralight Aircraft Museum. For a description of the aircraft read an assignment (MS Word document) on the CAB Wasp that Max Brown wrote in 2009 as part of a Museum Practice course.

Unfortunately the Australian Government regulations, though certainly enlightened for the times, restricted all flight operations to heights below 300 feet above ground level (agl) — to keep minimum aircraft operations below the 500 feet minimum operating height for general aviation aircraft. The aircraft were required to be single-seat, with a maximum empty weight of 115 kg, maximum empty-weight wing loading of 11 kilograms per square metre (2.25 pounds per square foot) and were prohibited from flying within 300 metres of a public road or within 5 km of an airport. Basically the airframes were made from 60 metres of aluminium tube and perhaps 35 square metres of sailcloth, and a lot of steel wire/cable. They were initially fitted with unreliable, low-powered, two-stroke engines — even chain-saw and mower engines — but quickly advanced to specifically designed engines with more capability. Such aeroplanes generally incorporated full three-axis control, but a few hybrid machines utilised a suspended, webbing pilot seat just for weight-shift pitch control.

The 300 feet restriction (slightly increased in 1985 to 500 feet) in the first edition of ANO 95.10; though reasonable at the time because of the lack of climb performance, was certainly not a pragmatic one, in the light of the subsequent rapid development in minimum aircraft capability. The aircraft all had poor engine-off glide performance ratios — maybe only 3:1; i.e. maximum wings level distance that could be flown, following engine failure at 300 feet, was 900 feet in nil wind conditions; a bit of a problem when you need a cleared area, with no livestock, quickly. Wind, manoeuvring flight and turbulence decreased that distance considerably. Also the first several hundred feet of the atmospheric friction layer are the most turbulent part of the lower atmosphere and particularly subject to wind shear events. And many of the pilots were self-taught.

There was another aspect in that, although ANO 95.10 exempted the ultralight movement from some provisions of the Air Navigation Regulations (now Civil Aviation Regulations), much of the regulations were still applicable. It seems that the authorities of the day may have turned a blind eye to minimum aircraft operations (perhaps believing that the movement would be a short-lived phenomenon) with undesirable results.

The Stolaero: Steve Cohen's and Frank Bailey's 1978 design. Three-axis control with a single-surface, wire-braced wing; later modification produced the Condor. Photo courtesy of the Australian Ultralight Aircraft Museum.

Work proceeded on the necessary systems and procedures and the essential AUF Operations Manual. The effort that the early AUF volunteer office bearers contributed was incredible, inheriting this big pool of enthusiastic flyers, who in many cases, knew little about aviation and, anyway, didn't want to. Unfortunately, the accident rate was making people sit up and take notice. The Bureau of Air Safety Investigation accident data for the period 1977–1985 indicated 77 accidents involving ultralights and causing 35 fatalities.

It is easy to be critical of those early years, however we should not forget that all flight operations were legislated to be below 500 feet agl with the inherent danger of forced operations at very low heights (something now considered unthinkable). This was exacerbated by aircraft with extremely limited flight envelopes (for example, only a 15–20 knot (30–40 km/hr) range between minimum and maximum controllable airspeeds) and with occasional stability problems.

Bantam B22S. The original B22 was designed and manufactured in New Zealand around 1987; production of the CAO 101.55 certified Bantam B22S training aircraft commenced in 1995. Photo of 24-3221 courtesy of Max Brown of the Australian Ultralight Aircraft Museum.

Each advance of MTOW, negotiated between the AUF and CAA/CASA over the years, while still restricting the seating capacity to pilot and one passenger, has made for safer, stronger Australian-manufactured aeroplanes that appeal – in terms of the hip pocket and reliability and ease of handling – to a much wider recreational community, and thus encourages interest in Australian sport and recreational aviation and revives growth.