Mainair Sports Merlin
A single-seat single-engined flex-wing aircraft with weight-shift control. Rogallo wing with keel pocket. Pilot suspended below wing in trike unit, using bar to control pitch and yaw/roll by altering relative positions of trike unit and wing. Wing braced from above by kingpost and cables, from below by cables; floating cross-tube construction with >70% double-surface enclosing cross-tube; pre-formed ribs. Undercarriage has three wheels in tricycle formation; no suspension on any wheels. Push-right go-left nosewheel steering independent from yaw control. Brake on nosewheel. Aluminium-tube trike unit, with pod. Engine mounted below wing driving pusher propeller. A ball race assembly is used to support the front fork for the nosewheel steering. All airframe tubing is bright ano-dised drawn seamless aluminium to British HT30TF specification. All bolts are aircraft quality AN series.
First shown in October 1982, the Merlin is Mainair's top of the range single-seat trike, and is produced in conjunc-tion with Airwave. It was conceived as an entity and is marketed that way, complete with purpose-designed wing, glass-fibre and fabric pod, and instruments.
The Merlin's most unusual feature is its wing connection, which is a modified form of the French connection often used in hang-gliding. Developed specially by John Hudson for this application, it is designed to give very light roll control, while absorption bushes reduce torsional loads transmitted to the trike unit.
Standard instrumentation is a Diplex altimeter and a Winter ASI; spherical compass, tachometer, CHTG, EGTG and vario are all optional.
Structurally and mechanically the trike unit is similar to the Tri-Flyer 330, though the main wheels' undercarriage is strengthened by using two axle tie wires rather than one.
Engine: Robin EC34PM en-gine, 35 hp at 6500 rpm.
Propeller diameter and pitch 54 x 30/34 inch, 1.37 x 0.76/ 0.85 m.
Toothed-belt reduction, ratio 2.3/1.
Max static thrust 190 lb, 86 kg.
Power per unit area 0.21 hp/sq.ft, 2.3 hp/sq.m.
Fuel capacity 2.6 US gal, 2.2 Imp gal, 10.0 litre.
Length overall 11.5 ft, 3.51 m.
Height overall 10.5ft, 3.20m.
Wing span 33.0ft, 10.06m.
Total wing area 165 sq.ft, 15.3 sq.m.
Wing aspect ratio 7.0/1.
Wheel track 5.5 ft, 1.68 m.
Wheelbase 5.8 ft, 1.77 m.
Nose-wheel diameter overall 14 inch, 356 mm.
Main wheels diameter overall 14 inch, 356 mm.
Empty weight 230 lb, 104kg.
Max take-off weight 438 lb, 199kg.
Payload 208 lb, 94kg.
Max wing loading 2.65 lb/sq.ft, 12.9 kg/sq.m.
Max power loading 12.5 lb/hp, 5.6kg/hp.
Max level speed 45 mph, 72 kph.
Never exceed speed 55 mph, 88 kph.
Max cruising speed 38 mph, 61 kph.
Economic cruising speed 32 mph, 51 kph.
Stalling speed 25 mph, 40 kph.
Max climb rate at sea level 660 ft/min, 3.4 m/s.
Take-off distance 80-120 ft, 25-35 m.
Landing distance 130-180ft, 40-55m.