Sportavia-Pützer SFS 31 Milan

The Sportavia-Pützer SFS 31 Milan is a single-seat motor glider that was produced in Germany in the early 1970s.

SFS 31 Milan
SFS 31
Role	Motor glider
National origin	Germany
Manufacturer	Sportavia-Pützer [de] Scheibe Flugzeugbau
First flight	31 August 1969[1]
Number built	14 by 1973[1]
Developed from	Fournier RF 4 Scheibe SF-27

Design and development

The Milan was created by essentially combining the fuselage of the Fournier RF 4 with the wings of the Scheibe SF-27.^[2][3][4] The resulting aircraft is a conventional motorglider design, a low-wing cantilever monoplane with a nose-mounted engine.^[1][4] The undercarriage consists of a single retractable mainwheel, a fixed tailwheel, and an outrigger under each wing.^[1][5] Construction is of wood, skinned in plywood and fabric.^[1][5] The designation was created by combining the initials of the manufacturers involved (Sportavia-Pützer [de], Fournier [fr] , and Scheibe), and adding the sum of the model numbers of the two constituent aircraft designs.^[1][4]

The SFS 31 prototype (registered D-KORO) first flew on 31 August 1969^[1][4] and soon replaced the RF 4D in production at Sportavia-Pützer.^[6] In 1971, Hans Huth piloted an SFS 31 to third place in the German national motorglider competition.^[1][7]

Specifications

Data from Taylor 1977, p.560, except as noted

General characteristics

• Crew: one pilot
• Length: 6.05 m (19 ft 10 in)
• Wingspan: 15.00 m (49 ft 3 in)
• Height: 1.57 m (5 ft 2 in)
• Wing area: 12.0 m² (129 sq ft)
• Aspect ratio: 18.6
• Airfoil: Wortmann FX-61-184 at root, Wortmann FX-60-126 at tip
• Empty weight: 310 kg (683 lb)
• Gross weight: 440 kg (970 lb)
• Powerplant: 1 × Rectimo 4 AR 1200 , 29 kW (39 hp)

Performance

• Cruise speed: 180 km/h (112 mph, 97 kn)
• Range: 670 km (415 mi, 361 nmi)
• Service ceiling: 6,000 m (19,700 ft)
• Maximum glide ratio: 29:1^[5]
• Rate of climb: 3.0 m/s (590 ft/min)