Microlight Design
The main goals are the same for all aircraft projects - simplicity, lightness and reduced drag. Initially, the innovative aspect of Rob's canard light aircraft (now microlight) concept was an absence of conventional control surfaces on the main-plane - making the aircraft lighter, aerodynamically clean and simple to rig.
Background
With encouragement from Manchester University lecturer (and canard advocate) Dr Terry Hughes, Rob experimented with canards in the mid 1980s. Together with fellow Solihull Model Engineers Club member, Adrian King, he designed his first canard model glider. The model was a two-function machine (rudder / elevator) with no control surfaces on the wing itself.
The prototype, constructed by fellow aeronautical engineering student, Andrew Twort, flew very well.
Rob's second canard project, the "Horizon", was designed for an MSc research project in aerial photography and weed-mapping. As stated by the late David Boddington, canards have some advantages in this role, not least, the convenient location of the centre of gravity and an ability to accommodate a large, relatively unrestricted payload bay.
Early experience with canard models proved useful but there remained one fundamental difference between model and full-size aircraft - the crew. Careful thought was given to the problem before selecting a two-seat side-by-side arrangement for the microlight concept illustrated in the video below.
Small-scale model tests indicated that there were significant shortcomings with the proposed control system. Modification of the system failed to improve matters and since this was the only innovative aspect of the design, further development of the canard microlight aircraft concept was suspended.
In 2009 an alternative development route presented itself, when commercially available electric light aircraft - such as the "Yuneec E430" - became a reality. With electric power and recent deregulation, single seat canard microlights offer a new opportunity for innovation.
Since 30th April 2007 it is legal in the UK to fly a lightweight ‘sub-115 kg’ single-seat microlight aeroplane without a permit to fly or any of the associated official design investigation, formal flight testing, maintenance schedules, annual inspections or permit paperwork. In this new category the onus is entirely on the owner/pilot to establish that the aircraft is in a fit state to fly. The only requirements in this new category are that the aircraft must have an empty weight not exceeding 115 kg, a maximum gross weight not exceeding 300 kg (330 kg for a float plane, seaplane or amphibian), an empty wing loading of no more than 10 kg per square metre, a stall speed less than 35 kts CAS and be a single-seater.
Here is the revised canard concept (now with conventional controls). In this form it is an electric-powered single-seater, with increased wing area to meet the 10kg per square metre requirement.
Even as Rob was dreaming of a canard to meet the new rules for deregulated microlights, design work was in full swing on just such an aircraft in association with University of Cambridge.
The aircraft is the rotary-engined winner of the LAA's design competition launched in response to the new deregulated class of microlights. Due to have its maiden flight in 2013, it is called the e-Go and was conceived by Tony Bishop and Giotto Castelli.
It's not surprising that Rob's musings look somewhat like the e-Go since the rules for deregulated microlights are the main design constraint. The e-Go will no doubt be a remarkable aircraft, however, this also means that our concept canard is not an innovation. For that we have to look elsewhere.
In January 1991, in the Royal Aeronautical Society's monthly magazine "Aerospace", John Crampton detailed his model aircraft experiments with vectored thrust and coined the term Aeropter for a light aircraft with such a system.
A canard is an ideal platform for vectored thrust and such a machine was patented by Lockspeiser in the 1980s (see adjacent image). Vectored thrust has the potential to improve control and STOL performance. An electric version would be both reliable and relatively simple to construct.
As a prelude to vectored thrust, AMDL has conducted tests using a small scale version of its Horizon canard with fixed electric motors, as can be seen in the short video sequence here.