Marske Aircraft Pioneer II

The lighter Pioneer II-A was developed for homebuilt construction, with a glass-fibre fuselage and separate ailerons and flaps. Redesigned from the Pioneer IA, the wing has, had the span reduced to 13 m so it could be built in a standard 20 ft. garage. Upper-and-lower surface airbrakes are used for glidepath control. Because a tailless sailplane has a narrow centre of gravity range, an adjustable seat was positioned above the fixed landing wheel, which itself is on the centre of gravity. The pilot simply moves the seat until his/her own weight balances the ship on the wheel. It made its first flight in 1972. The following model, Pioneer II-B, had a longer canopy and a section based on the NACA 33012/33010 allowing an improvement in low speed performance. The Pioneer II-C included a few simplifications and lightening of the fuselage structure.

Model Pioneer IID, went into production, is distinguished primarily by its swept fin and modified wing leading edge. Its maximum glide ratio is 35, despite a low aspect ratio (less than 13). Stall speed is below 60 km/h, and the glider is stall resistant and completely spin proof. It was sold as a kit to amateur builders, assembly requiring approximately 600 hours.

At least one Pioneer II has been modified by adding tip extensions to increase the wingspan to 14.0 m.

A P2 that was modified by Jay Johnson in McCook Nebraska had the conventional rudder replaced with spoilers operated by the pedals. A fixed fin replaced the rudder. Slow, tight turns required almost no spoiler and the combined effect of ailerons and spoilers produced a very fast roll rate of around 3 seconds in a 45 to 45 degree roll.

Pioneer II
Wing span: 12.98m /42.64ft
Wing area: 13.8sq.m /144sq.ft
Aspect ratio: 12.6
Airfoil: Modified NACA 33012/33010
Empty Weight: 172kg /380lb
Payload: 113kg /250lb
Gross Weight: 285kg /630lb
L/D Max: 35 97 kph / 52 kt / 60 mph
Min Sink: 0.7 m/s / 2.26 fps / 1.34 kt
Wing Load: 20.65kg/sq.m /4.4lb/sq.ft
Seats: 1
No. Built: 15

Pioneer IID
Top speed: 130 mph
Cruise: 95 mph
Stall: 35 mph / 57 km/h
Aspect ratio: 12.59-1
L/D / Glide ratio: 1:35 at 97 km/h
Min sink: 126 fpm / 0.70 m/s
Landing dist: 170 ft
Empty weight: 350 lb / 159 kg
Gross weight: 600 lb / 295 kg
Height: 5 ft
Length: 12.5 ft / 3.81 m
Wing span: 42.6 ft / 12.98 m
Wing area: 144 sq.ft / 13.38 sq.m
Airfoil: NACA 33012 - 75
Seats: 1
Landing gear: single wheel