Paton Monoswift

For Maurice Paton of Canterbury, New Zealand, his requirements were to design an aircraft that was bigger than a Corby Starlet and about the same size as a Thorp T18, but to be a single seater and meet the microlight rules.

With all of these ideas in mind Maurice sat down at his computer and with the help of the C.A.D system he designed his Monoswift over a period of six months. The next step was to build a 3D surface model to prove the concept. Then followed the Printing of detailed drawings of all the components at full size. This made the building easier and very accurate because each piece was built directly on top of the drawing.

Western Hemlock is the main type of material used in the construction, with fibreglass being used for the wing tips and the belly fairings.

The engine option was the water-cooled 3.9-litre Rover V8 using a single, two-inch SU carburettor (instead of fuel injection) and a radiator belly scoop, which direct drives a ground adjustable, 68-inch, three-blade Warp drive propeller via a custom made adapter to the flywheel end of the crankshaft. Fuselage construction is basically a wood and ply box section, with formers for the shape and fibreglass for the non-structural cowlings, wing tips, etc.

The undercarriage is a tailwheel configuration with the main wheels attached to the main spar and folding into the lower fuselage. Engine cooling is via a radiator housed beneath the fuselage. The starting point for the drawings was a Thorp three-view, with a radiator belly scoop and a larger rudder, the undercarriage moved to the wings, a raised rear turtle deck and a reshaped engine cowl. The wing is a single piece and based on the Sirocco (that is, a box spar with no dihedral but given one degree of washout at the tips).

From start to finish the Monoswift took Maurice three years and two months to build.

The aircraft, sn MPS001, was first registered, to M J Paton, Rangiora, New Zealand, on 24 September 2003.

The aircraft was flown by Maurice from his home strip "Barraca" to the Rangiora airfield on 26-10-2003.
Maurice reports it just flies like any other plane with no real surprises. After eight hours he found it to cruise at 130 kts, stalls at 38 kts and uses 25 litres/hr. The manually operated system for the retractable undercarriage works well although there is noticeable drag on the aircraft when the wheels are going down. He approaches at 55-60 kts over the fence with good forward visibility and finds the aircraft easy to control on the ground.
The empty weight has come out at 9001bs which allows for 300 Ibs. for fuel and pilot etc. Maurice is using a 3 blade, direct drive, ground adjustable propeller but has found that he is running out of pitch adjustment in flight. So he has purchased a new warp drive in-flight adjustable propeller which should see the cruise speed increase to 145-150 kts. The only other mod he is considering is to add a trim tab on the elevator to unload the stick forces when the flaps are fully extended for approach and landing.

Engine: 1 x 3.9-litre Rover V8