A SCALE TWIN OF DISTINCTION

Alex Whittaker delves into a scale masterpiece from the secretive ‘Spartacus’, his 118-inch span Miles Gemini

Conceived as a four-seater light touring aircraft the Miles Messenger twin first flew on the 26th October 1945. The prototype was powered by a Blackburn Cirrus Minor engine. It was of wooden construction and had a retracting undercarriage.

The pretty Gemini was sold as ‘The Safest Light Aircraft in The World’, referring to its twin engines. The Gemini proved popular with customers and 130 were sold in the first year. However, the Miles Aircraft Company had deep-seated financial problems and ceased trading in 1947. Eight further aircraft were assembled by Handley Page, Wolverhampton Aviation and F G Miles Ltd.

Private owners used the Geminis in their intended rôle as a safe air-tourer but soon many owners were racing them. Indeed, G-AKDC won the 1949 King’s Cup Race. Some were used for charter work and others were pressed into light business transport by the likes of Shell-Mex, BP and Fairey Aviation. In all 170 were built in the first production run, with the last two variants being completed in 1951 by FG Miles Ltd. These distinct types had Blackburn Cirrus III engines and were fitted with taller enlarged fins and bigger rudders. These were designated Miles M.75 Aries.

It is little known fact of aviation history that the Israeli Air Force operated at least one Miles Gemini.

THE MODEL

I first saw this fabulous model in 2015 and it made an immediate impression of unusual quality. This exquisite Gemini is 118” in span, weighs 39lbs (which is light) and was originally powered by two Super Tigre glow motors.

Now the truth is the Miles Gemini is a criminally under-modelled scale subject. Older readers will remember Dr Jeremy Shaw’s famous Gemini, which was a good bit smaller than the example featured here. Noted scale man Duncan Hutson also produced a well-known and very pretty Gemini. The Gemini shown here was then under the custodianship of noted scale modeller Steve Woodhead. However, she is on long term loan from the secretive (and reclusive) ‘Spartacus’.

Spartacus is one of the United Kingdom’s very best – and most celebrated – large scale model builders. However, he is famously elusive and prefers to keep out of the limelight. Over the years, we have featured a range of stunning scale models which Spartacus has designed and built, usually as a collaborative project with equally gifted Chris Peers. These include the celebrated Miles Messenger, Fairey Firefly and Percival Proctor. In fact, Spartacus conceived his Miles Messenger and Miles Gemini as a ‘Display Double’ for the summer shows. Both airframes display similar Spartacus design features, building techniques and finishing.

CONSTRUCTION

Spartacus uses only traditional building techniques, preferring an all-wood construction, plus the addition, here and there, of hand-made glass reinforced plastic components where necessary.

The Gemini cleverly uses rolled ply in the fuselage to deliver its distinctive scale appearance. The undercarriage doors are GRP mouldings. However, the prominent nose cone is not a GRP moulding, as might be expected. To get the authentic shape and vintage feel Spartacus elected to fabricate it entirely built-up from balsa wood and ply. This extra effort ensures that the airframe looks utterly faithful and has no discontinuities or joins in the nose area.

CANOPY & DOORS

The canopy blank and cabin windows were carved from block balsa. Then the transparent sheet plastic was heated, and hand drawn over the block to take up the shape. There is a lot of scale detail work in the opening gull-wing doors.

UNDERCARRIAGE

Much of the sturdy metal scale retracting undercarriage, complete with dampers and shock absorbers, was fabricated on a Myford ML7 lathe and a milling machine.

The 4.5″ wheels were originally Sullivan Skylites, with home-made scale hubs. Later, DuBro solid types were used.

ENGINES

The Gemini was originally fitted with twin Super Tigre 2500 glow engines. Steve Woodhead replaced these with twin Zenoah 25 petrol engines for increased reliability and more power.

Steve modified and fitted twin Zenoah 38 exhausts, which are smaller than Zenoah 25 units and they fit within the cowls.
The Gemini uses twin 18” x 8” propellers.

RADIO

Steve used Futaba 2.4 gig radio with seven servos.

PAINTING

The model has a traditional dope and tissue finish, with many coats of sanding sealer and lashings of intermediate sanding down. The Gemini is finished in Flair enamel paint, which was then fuel proofed and sealed with Ronseal Satin Varnish. This was thinned down and sprayed on.

Since the prototype is an all-wood airframe there is not much rivet detailing, save those on the cowling.

GROUND LOOPING

As seems to be the case with other R/C model Geminis she was originally prone to ground looping. This was traced to two areas – slightly binding main wheels and the scale-position, but forward set tailwheel. The main wheels were changed, as mentioned above, and the tailwheel geometry subtly altered. These canny tweaks effected a cure. This is a classic example of the application of considered modelling, building and flying experience applied to solve an issue with a scale model.

FLYING NOTES

Spartacus conducted his own test flights at Langar airfield, with later flights at RAF Scampton. After the flying qualities of the model were proven the Gemini was loaned to Steve long-term, by a very generous Spartacus. Steve later re-engined her as above.

Steve reports that she now flies like a trainer on low throttle and a WWII fighter on full throttle! No shortage of power at all. Aileron response is very positive, though she needs a touch of top rudder on the steeper turns. Spartacus is famous for the accurate scale ‘sit’ of his models in the air, plus their correct attitude when flaps are applied on final approach. This is to down the well-thought-out incidences and rigging angles built into the model and not to do with any superficial transmitter mixes. In fact, Spartacus used simple Y-leads to drive the ailerons and flaps, one channel for each function.

Steve reports that the Gemini is very happy on half throttle and approaches are slow and controllable all the way down. She has a substantial amount of wing area and is not prone to stall. Steve says she is the nicest twin he has ever flown, and he should know. Readers may remember that Steve and his father, Robin have produced a number of noted twins of their own design over the years, including their Caribou and Tiger Cat.

DATAFILE

Model name: Miles Gemini
Designer: Spartacus
Wingspan: 118″ (2997mm)
Weight: 39 lbs (17.7 kg)
Engines: 2x Super Tigre 2500 (later fitted with 2 x Zenoah 25)
Props: 18” x 8”
Retracts: Home made by Spartacus
Wheels: 4.5″ Sullivan Skylites (later fitted with Du-Bro solids)