S. E.5a Biplane
Built by Richard Marsden in March 2024 for the Meccano Magazine Cover Models Secretary’s Challenge
‘Build something unusual’, said the Secretary. Well, this is only the second aircraft I’ve built to my own design. The others were mini-models and the Red Arrows jet, and I’m not counting the dumpy little aircraft I built for the Children’s Carousel. So this is unusual for me!
The S. E.5a featured on the front cover of the Meccano Magazine of April 1963, in flight somewhere over England. That’s a guess, but a cricket pitch and some goalposts are visible on the ground below.
A Google search revealed a lot of useful information, including some plan and elevation drawings. The aircraft was 20’ 11” long, with a wingspan of 26’ 7”. The model is about 17” and 20”, so that makes the scale about 1:16. The wheels are slightly overscale; 1½” pulleys and tyres would have been closer but would not have looked right.
The eagle-eyed enthusiast will have noticed that my model when photographed had a two-bladed propeller, which I have now upgraded to four blades. Exactly the same thing happened to the real thing. Which was why I did it that way of course, and not because it wasn’t apparent from the magazine cover photograph that there were four blades!
The prototype of the real thing appeared in late 1916, and after a very sad and unfortunate start (two crashes and a fatality), and the fitting of a more powerful engine, over 5000 were built. The initial version was denoted the S. E.5 and a few S. E.5b’s were made with a revised nose. Only about half-a-dozen S. E.5a’s remain, perhaps two in flightworthy condition. Some flying and non-flying replicas have more recently been built for museums and film work.
Aerodynamics seems to have been more an art than a science in 1916. The wings have a very slim profile, not much of an aerofoil, and would not have generated much lift for their area. The modest airspeed, quoted variously as between about 120 and 138 mph, would not have helped either. But the speed was respectable for the time, and the aircraft was simple to build and economical in materials. There would have been an interesting set of engineering compromises for its designers to consider — isn’t there always? Wings with a more pronounced profile would have generated more lift, but maybe also a little more drag, requiring a still more powerful engine — heavier, thirstier, more stressed and less reliable? Would the extra complexity have been worth it? Indeed, anyone brave enough to try designing a monoplane?