I have not seen it written anywhere, but I like to think that there are at least four waves of microlight evolution. The original microlights mirrored aircraft designs that existed before WWI with a variety of types similar to those that entertained the public in the comic film: 'Those Magnificent Men and Their Flying Machines'. The second wave settled on more conventional designs, constructed from alloy tube and 'sailcloth', they recognised the crew's need for some protection from the elements. The third generation usually made use of the light and powerful (80 or 100 bhp) Rotax 912 engine, higher speeds bought the need to control parasitic drag, these microlights look like conventional aircraft. The fourth generation are of composite carbon construction, superbly streamlined, of elegant outline; they are collectively known as 'Rocket Ships' on account of their amazing performance, all achieved with the aforementioned Rotax 912. The price tag of these planes is commensurate with their performance.
One local firm has recently restarted the manufacture of a long established design that I would categorise as a 2a, the design originated as a 2 but constant development has moved it towards a 3. It took the firm with the manufacturing rights a couple of years to obtain type approval from the CAA. Type approval that was necessary if they were to re-commence manufacture. All this despite the design being long established, respected, and used in many flying schools. It is little wonder that, all of the 'Rocket Ships' are manufactured abroad, mainly in the USA or Eastern Block countries.
As I understand the situation, the major component in the delay that prevented manufacture of this microlight restarting is best described as bureaucracy. The long turn round time for paperwork that officialdom deems acceptable, but which delays manufacture, and stifles innovation.
The MSA has recently circulated proposed regulation, 19.14,9 to clubs. It states: all new design single seater space frame chassis vehicles intended for first use, within a Championship or Series from 01/01/2012 must comply with relevant sections of FIA Appendix J, Article 277. Reason: Safety. Aligning national standards for single seat spaceframe chassis with the FIA.
19.14,9 represents a new certification requirement for spaceframe chassis. The MSA cites 'safety' the universal incontestable justification in this secular age, and aligning national standards. Do the reasons given address a real need in the UK? With regard to safety, are the chassis we currently race deficient in some way? Or is the MSA introducing requirements, thought up by bureaucrats, whose sole effect will be to delay the production of UK built new chassis, and stifle innovative design? I am in awed admiration of those MRC members who have designed, built, and continue to design and build their own cars. A level of determination that I cannot muster is required to complete such a project, the satisfaction on the successful completion of such a project must be considerable. One anticipates that the intention of the MSA to adopt Appendix J, Article 277, will make these individual’s task much more difficult and expensive.
The MSA cite Appendix J Art 277, a long and detailed document which naturally I have not read, one can however assume that as well as making a large number of specific design requirements, it includes testing, with all the detailed expensive bureaucracy this implies. It is quite possible that the MSA is proposing the introduction of a testing requirement without a suitable testing facility being available. The relatively few new chassis designs that appear annually could not support a dedicated facility, this could well mean that the testing requirement be prohibitively expensive.
Our Club Co-ordinator, Simon Davey has sent a letter to the MSA which makes many similar points, including that the Monoposto Racing Club, like the UK motor racing industry, has a proud heritage of competitors racing self built, or small production spaceframe cars, and that there is not a problem with injuries caused by inadequately designed and built spaceframes. If safety was really driving the introduction of this regulation, logic would dictate that the regulations first address two seaters, not single seaters, as the larger cockpit gap in their chassis make them inherently weaker.
Problems can occur when designing to regulations rather than to best practice, for example recent press discussion is on the topic of roll hoop failures in chassis built and tested to FIA specification. Such cases should come as no surprise because once a regulation is ratified it can be expected to evolve at the rate of a dinosaur fossil. For example I was discussing engine subframe failures (small spaceframes) in light aircraft with a CAA inspector recently, (Why? Don't ask, just think anorak). The inspector explained that it was not a design problem, but a construction problem. The welding of these tubular structures has to be performed by a CAA certified welder, and the test criteria for the skill of these welders dates back almost to WWII, i.e. in the twenty first century these criteria are inadequate, thus some CAA certified welders produce inferior welds. But the Catch 22 is that all welding on light aircraft must be done by a CAA certified welder. Be warned if such an individual offers to weld up some wishbones for you!
A Classic microlight
The German "Silence" microlight. Its eliptical wing is said to make it resemble the Spitfire. It is an Aramid/GRP composite (not carbon) with a Wankel engine.
Meanwhile, here are a few special builders.
Eric Broadley's first car was a homebuilt...
...before he made the the Lola Mk1