Economy flight

A light aircraft uses an alternative design and materials to maximise its capabilities

A canard aircraft design that claims to push the boundaries of performance and fuel economy is nearing completion following collaborative testing with Cambridge University.

Initially conceived by aeronautical engineers Tony Bishop and Giotto Castelli, the e-Go aircraft has been created in response to new regulations by the Civil Aviation Authority (CAA) aimed at promoting light aircraft design in the UK. Since the rules were introduced in 2007, the design has gained popularity, prompting the pair to form a company in order to develop the design with a view to commercialisation.

Bishop said: ‘Our aim is to push the boundaries for maximum performance by creating something that is both lightweight and highly resilient. To do this we’ve had to test the limits of structural and aerodynamic technology. That’s also led us to stretch ourselves with regards to manufacturing processes because we’re using a fairly unusual combination of materials.’

One such material is the latest pre-preg carbon fibre that can be cured at temperatures as low as 65°C. Bishop explained: ‘We’re using the carbon fibre in remarkably small quantities so we finish up with very thin webs. However, to stabilise the structure and get the weight down we’re using a carbon cloth that is pre-impregnated with a resin.

‘Fortunately, recently they’ve come out with a pre-preg carbon fibre that can be cured below the melting point of foam, so we’re co-curing it with the foam, which is, as far as we know, probably a first. That, combined with using computers to use the absolute minimum of foam and carbon fibre we need to stabilise the structure, has led us to develop the current design. At the moment, we think we’re building the wing about 25 or 30 per cent lighter than anyone else has managed so far.’ Supporting the e-Go’s efforts, two students at Cambridge are separately working on testing the designs aerodynamic qualities using a low-speed wind tunnel and advanced computer analysis techniques. The students are then comparing their results in order to suggest improvements and possible safety concerns.

Bishop added: ‘Both of these methods have their limitations and strengths, but between the two of them we should get the best of both worlds in terms of results. One thing we’re paranoid about is making it very safe. The main thing is how it stalls and this is one of the main reasons for using the canard.

‘On our design, the small wings are on the front of the plane rather than the back and the effect of this is that when you approach a stall, it’s the canard that stalls first, so the plane just nods gently. The problem is in practise, getting the aircraft in a position where the main wing stalls is actually quite dangerous because its hard to get out of, so as far as possible we’re trying to do all our critical testing on the ground using computer and wind-tunnel simulations.’

The team currently have a working design and are hoping to begin flight tests within the next year.

Ellie Zolfagharifard