Short-Mayo Composite in 1/144 Scale

By Joel Christy

Introduction

I was inspired to build the Short-Mayo Composite model after browsing through the book, A Century of Manned Flight by Richard Townshend Bicker. In it was a bit about the Short-Mayo and some excellent photos of the two aeroplanes and the gantry that the smaller S.20 seaplane was attached to the Short S.21 flying boat. Modelling the latter aircraft, called Maia (a star in the Pleiades constellation), was not going to be a problem. Welsh Models make a vacform of the Short S. 23 which is almost identical to the S.21. However creating the smaller Mercury was another matter. I never did find a definitive plan of the aeroplane and I had to use a profile and a photo of a model of the Mercury I found on the internet. Be that as it may I carried on with what you see.

The whole idea of a composite was thought up by Imperial Airways Technical manager, Major Robert Mayo. He felt that by lifting a smaller aircraft to altitude with a larger aeroplane and releasing it, the smaller heavily laden aircraft would have a greatly increased range. And it did work; one flight initiated in Dundee ended up as a 6,000 mile flight to South Africa, a record for a seaplane. However the Second World War intervened and the idea was scrapped. An idea , I might add, that is today being used by Richard Branson in his space touring shuttle.

The Models

As already stated the larger Maia aircraft was an easy type to model. The Welsh Models vacform kit is typical of that company’s product and it is a joy to build, providing one is used to vacform construction. The only real alteration I made was to the vertical tail which has a slightly more square appearing top to the one on the S. 23 Empire Class flying boat. The kit version I used had beautiful white metal engines that enhanced the final overall appearance of the model.

To make the model of the Mercury I was dependent on a colour profile of the Short-Mayo Composite that I found on the internet. After printing it off I scaled the picture to 1/144 . This gave me the shape of the fuselage, fin and floats. The profile also showed me the location of the wings on the fuselage. As I had the scale wingspan I was able to determine the wing’s shape with the photos I had of the Mercury. I used Harry Woodman’s method of a built up wing made of sheet styrene. This involves curving the plastic over a spar and ribs to get the proper airfoil shape (see wing illustration). The profile indicated that the wings had a long fillet at the root and I incorporated this into the plastic sheet before I folded the plastic over the ribs and spar.

Setting aside the wings I turned to the fuselage. I decided to plunge form 20 thou plastic sheet over a wooden plug and make two identical fuselage halves.(See fuselage illustration). Again I used one of Harry Woodman’s methods. Once I had the two halves made I reinforced them with round formers before gluing them together. I also glued narrow strips along the length of one half to achieve a lip to glue to where the two halves meet. Once all was assembled the fuselage formed a cigar shape. I sanded this item down to get rid of the seam after it was thoroughly dry.

I cut tail surfaces from 40 thou plastic sheet and sanded them to shape before gluing them to the fuselage. Next I marked off the location for the wings and glued them to the fuselage making sure the wings were correctly positioned and aligned with the tail surfaces. When all of this was dry I cut out the windscreen area. This was easy in the case of the S.20 as it was a very streamlined aircraft. The lines flow right through the shape so there is little difference in form along the whole fuselage. So by simply cutting two slots in the nose I was able to form the cockpit area.

When I was satisfied with the wings and fuselage assembly I turned to the seaplane’s floats. Again I made a wooden plug for the top half and plunge formed 20 thou sheet. Once I had cleaned up the halves I made a spline down the centre of the plunge formed halves. Once dry I cut 4 pieces of 20 thou sheet to form the hulls of the floats. When the two assembled floats were quite dry I sanded and cleaned them up. I then gave the main body and floats of the Mercury a coat of liquid poly for a nice smooth finish.

Next I turned to the four Napier “H” engines used on the S.20. Each of these were made of 20 thou sides with a slot to fit over the wing’s front edge. The four spinners were plunge formed over a bit of pointed sprue. When the engines were completed and installed I attached the floats to the underside of the model. This was tricky and it took several tries to get the right length to the struts. I had already attached the gantry to the Maia flying boat model having completed and painted it earlier. The difficulty lay in the fact that the floats of Mercury had to clear the propellers of Maia. I had to trim both the gantry and the float struts to get the right set to the completed model. Trial and error was the only solution but it turned out OK in the end.

Both models were painted with Tamiya silver leaf from a spray can. This excellent product gives the model a fine overall covering with no visible silver grain to the finish. Care must be taken though to prevent runs or a build up of paint on the edges. For the bronze coloured exhaust rings on the Maia engines I used Tamiya clear orange over the silver. A coat of Klear/Future mixed with Tamiya white base toned down the shine.

I found an excellent photo of the Short-Mayo Composite on the internet showing the aircraft on its beaching dolly. It clearly showed the details and relative size to the two aeroplanes. I made it up out of 20 and 40 thou plastic sheet and added the railings from brass wire. The latter were probably used to man-handle the dolly under Maia whilst in the water.

Conclusion

With the two piggy back aircraft sitting on their dolly I had a finished model of the Short-Mayo Composite. I have to admit to a penchant for strange aircraft and they don’t come much stranger than these two! However, in their time they were cutting edge and they did work. Had there been no World War Two who knows where the technology would have gone? As it was the Luftwaffe conducted several experiments with piggy-back aircraft. Even today efforts to get tourists into space are relying on a similar technology. Was it worth building the Short- Mayo? Yes is the answer and I probably have one of the only ones in existance; a real rara avis!


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