Warning: gorgeous airplane up ahead. Uncontrollable drooling may be unavoidable.
The Airelle was a two seat tandem wing kit aircraft design by the French Aeronix company. It first flew in 2002. A beautiful design, the company went out of business in 2006 before its potential could be realized.
Very little information on the design is available. Only about five were built, which limits the number of people with first hand experience with the design. Given that it was a French design, finding information in English is even harder.
It superficially resembles several of the designs of Burt Rutan. It is easy to mistake the front wing with a canard surface. I don’t know at what size the front foreplane ceases being a canard and officially becomes a front wing. It might be up to the designer to declare it as one or the other. Anyway, in the Airelle the span of the front wing is 80% of the span of the rear wing. A canard surface is normally 50% of the span of the wing or less.
I designed, built, and flew a tandem model airplane once. Both wings were identical in size and shape. It’s a very interesting configuration, and I hope to design and build another one someday soon. Having two identical wings had several interesting advantages, which I plan to explain someday. But a problem with the tandem wing design is that the rear wing is going along for a free ride, so to speak. To have pitch stability, the center of gravity has to be quite a bit closer to the front wing.
Push-Pull Engine Configurations
A very unusual aspect of the design is the twin engines in an inline configuration. I don’t know why they decided to design their airplane this way. I have a hunch that their primary motivation may have been to bring the center of gravity of the airplane to the middle of the cockpit. That avoids a whole host of weight and balance problems that canards are known to run into.
A problem that twin-engined airplanes have is lower efficiency. Two smaller propellers are less efficient than one bigger one. Initial and maintenance costs are considerably higher in a twin. With 40 hp in each engine, I don’t know if one-engine out performance was a selling point. That’s probably enough power to maintain some sort of cruise flight, but it would be very marginal in a 1,000 pound airplane (450 kg).
A big difference from the Rutan Long-EZ is the side-by-side seating. I have flown in both configurations, and being seated right next to the other person in the airplane is just a friendlier way to fly.
The large canard surface right in front of the cockpit at waist level did not do anything good for visibility forward and down. But visibility to the side and down is excellent, which more than makes up for it. With those huge windows, the Airelle seems like a perfect airplane for going sightseeing.
Creating the Model
How hard would it be to create a scale model of the Airelle? With no three-view drawings, no flying airplanes, and a limited selection of photographs, creating a highly accurate scale model would be a challenge. But there is definitely enough information available for creating a great looking model.
This is a very good looking airplane design. It would make an excellent scale subject. If you build one, be sure and let me know about it!