Tabloid means to compress or condense. This was a suitable name for the full-size which for 1913 was a practical machine of modest proportions. However, when Ian decided to build a 50% scale model this does not seem quite appropriate! The full-size was built, by Sopworth, as an exhibition aircraft with pilot and passenger side by side. It achieved a remarkable speed of 92mph using a Gnome rotary engine.
The Aeromodeller scale drawing No 2751 provided Ian with a good three view drawing and an excellent sketch page showing constructional methods. From this half-size drawings were produced on lining paper in the Autumn of 1990. A lot of time was spent working out wood sizes as with a short nosed aircraft it would have been easy to have needed excessive nose weight.
The main structure is made from Columbian pine with ash for the undercarriage and centre section struts. To achieve the sharp curves at the front of the fuselage the longerons were slit lengthways with a 1/16″ circular saw and glued in a jig. Waterproof PVA was used as the adhesive for this and most of the structure. The side frames were made and joined inverted on the bench. Stainless steel corner brackets and internal scale bracing wires were added and tensioned. A total of 214 brackets and over 400 fixings were fitted.
The fuselage was removed from the bench after fitting the ash undercarriage; the curved top formers, stringers and ash centre section were added later.
The wings use balsa covered ribs with spruce capstrips, 1 3/8″ x 1/2″ main spars and 7/8″ x 3/8″ rear spars. The wing tips and tail outlines were produced from laminated strips of 1/16″ spruce. Stainless steel hinged plates were used for the outer struts. These plates are bolted to the wings using 4mm Allen screws.
The forward fuselage is clad in 24swg aluminium and the nose top and bottom cowlings were beaten from 20swg aluminium held on with over 300 small self tapping screws. The cowl starts straight, but rapidly changes into a double curved shape. This was formed using a wooded mallet and a sand filled leather bag. Repeated annealing was necessary to get the cowl shaped correctly without it splitting. The wheels are 14″ diameter small cycle wheels on 10mm split axels, bungee sprung, having bearings of phosphor bronze.
Pete’s pilots provided the pilot and passenger who due to the compact cockpit appear to be very good friends!
Covering is Polytex ‘linen’. Balsarite was used to aid adhesion to the pine/spruce. The covering was finished with a mixture of semi-matt coloured varnishes.
Radio is Futaba PCM with main batteries of four cell 4A and a backup of four cell 1.5A. These are positioned in the nose cheeks to help with the location of the centre of gravity.
Wing warping is achieved via brass pulleys and 49 strand, 1.5mm diameter, stainless steel wire with a breaking strain of 380lbs. Becker, 20kg servos are used. One was calculated to do the job, but two were used to be doubly sure!
The elevator servo is also a Becker 20Kg and the rudder seervo is a 9kg Multiplex power servo. The throttle servo is a Futaba S131S.
Twenty seven turnbuckles were made from 1/4″ diameter brass with a 4mm thread.
Wing incidence is 2 1/2 degrees, tail incidence 1 degree and the centre of gravity is at the 30% average cord position. The wing warping has a movement of 1″ up and down.
The test flight was made at Goosedale in May 1991. Wing warping is not as effective as having ailerons as it creates adverse yaw. The turns are hence started with rudder and then co-ordinated using wing warp and elevator.
Ian says that he has come to really enjoy flying the model. It has to be treated ‘a bit like an old lady, careful considered inputs, gentle progressive control’.
The rudder is scale and consequently too small. The model tends to wander and needs constant gentle rudder inputs to keep the model flying straight. The model does a nice scale loop, stall turns, wingovers, spins and impressive touch and goes.
The King engine has been superb. It is smooth and powerful. Starting is easy and very predictable. Once choked the engine requires a pull over compression rather than a strong flick. The last time the engine was adjusted was in 1993. The spark plugs were replaced in 1997.
The model is now on its third set of batteries, second set of servos and second set of rigging wire (now 1.7 mm diameter).
Ian says that of all the models he has this is the one he enjoys flying most. It is challenging enough but, with its slow airspeed, you can still enjoy watching it.
As of November 2001 the model has had 290 flights.
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