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Orliński RO-7 Orlik

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RO-7 Orlik
Role Homebuilt aircraft
National origin Poland
Manufacturer Roman Orliński
Designer Roman Orliński
First flight 22 February 1987
Number built 1

The Orliński RO-7 Orlik (Eaglet) was a prize-winning Polish home-built aircraft, first flown in 1987. It was restored to flight, with improvements, in 2003.

Design and development

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Roman Orliński began to design the Orlik in the spring of 1984. Its first flight was made on 22 February 1987.[1]

It has a two part, low, rectangular plan, wooden wing set with 5° of dihedral and built around a single main spar. Plywood skin ahead of the spar around the leading edge forms a torsion-resistant D-box; behind the spar the wing is fabric covered. Its ailerons, mounted on an auxiliary spar, fill a little under half the span.[1][2]

The forward fuselage has a welded steel-tube structure but the rear is a wooden monocoque; throughout, the section is essentially rectangular with rounded decking. Behind the metal-covered, conventionally mounted engine, a Walter Mikron III salvaged from an earlier project, the forward fuselage is ply covered. The cockpit is over the wing, normally enclosed by a two-part canopy though it can be flown open with only its windscreen in place.[1][2]

The Orlik's tail is conventional and angular, its tall, trapezoidal profile fin carrying a similarly shaped, balanced and tabbed rudder. Its rectangular plan tailplane is mounted on the top of the extreme rear fuselage, placing its straight-edged, tapered, one-piece, tabbed elevator behind the rudder. The rudder is entirely fabric-covered and the elevator largely so.[1][2]

The landing gear is conventional and fixed, with steel tube, V-strut main legs hinged from the lower fuselage longerons. Each leg is cross-linked to the top of the other with a steel rod and has an elastic shock absorber within the fuselage. Originally the rather small wheels were exposed. The castoring tailwheel was on a long, trailing spring.[1][2]

The Orlik proved to be easy and pleasant to fly. Criticisms were confined to its landing limitations; the absence of flaps meant a shallow approach, the absence of brakes could be a problem at short strips and its small wheels did not suit rough surfaces.[1]

After a period of disuse the Orlik was quickly restored to flight in mid-2003. Photographs from that year show the wheels enclosed in spats and flaps which occupy all the trailing edge inboard of the aileron. It underwent a series of quantitative tests with results good enough to encourage Orliński's son to start a second airframe in 2004.[1] It is not known if this was completed.

Operational history

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Five months after its first flight in 1987 the Orlik appeared in public for the first time at the 6th Amateur Constructors' Rally. It made a good impression and took one of the two first prizes. After restoration and tests in 2003, it flew in public at an Air Force open day in September 2010.[1]

Specifications

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Data from Jane's All the World's Aircraft 1990-91[2] except where noted.

General characteristics

  • Crew: one
  • Length: 5.50 m (18 ft 1 in)
  • Wingspan: 7.60 m (24 ft 11 in)
  • Height: 1.95 m (6 ft 5 in)
  • Wing area: 8.75 m2 (94.2 sq ft)
  • Airfoil: NACA 23012
  • Empty weight: 220 kg (485 lb)
  • Gross weight: 320 kg (705 lb)
  • Fuel capacity: 30 L (6.6 imp gal; 7.9 US gal)
  • Powerplant: 1 × Walter Mikron III four-cylinder, air-cooled, inverted inline, 48.5 kW (65.0 hp)
  • Propellers: 2-bladed SRO-10[1], 1.47 m (4 ft 10 in) diameter

Performance

  • Maximum speed: 150 km/h (93 mph, 81 kn) at sea level
  • Cruise speed: 90 km/h (56 mph, 49 kn) economical, at sea level. Later (2003) tests reported 115 km/h (71 mph; 62 kn) at an unspecified altitude.[1]
  • Stall speed: 71 km/h (44 mph, 38 kn)
  • Range: 400 km (250 mi, 220 nmi) with 20 min reserves
  • Rate of climb: 5 m/s (980 ft/min) at sea level

References

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  1. ^ a b c d e f g h i j "RO-7 "Orlik Experimental", 1987". Retrieved 27 November 2019.
  2. ^ a b c d e Lambert, M. (1990). Jane's All the World's Aircraft 1990-1991. London: Jane's Information Group. p. 552. ISBN 07106 0908 6.