IIL IS-8: Difference between revisions
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The '''IIL IS-8''' was a two seat |
The '''IIL IS-8''' was a two seat [[sailplane]] designed by Iosif Silimons and built in [[Romania]] in 1960. They served with Romanian gliding clubs. |
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==Design and development== |
==Design and development== |
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From about 1950 to his death in February 1981, Iosif Silimon was Romania's most prominent glider designer, his aircraft distinguished by his initials.<ref name=JAWA81/> The IS-8, a two seat [[shoulder wing]] [[cantilever]] [[monoplane]], first flew on 14 September 1960. |
From about 1950 to his death in February 1981, Iosif Silimon was Romania's most prominent glider designer, his aircraft distinguished by his initials.<ref name=JAWA81/> The IS-8, a two seat [[shoulder wing]] [[cantilever]] [[monoplane]], first flew on 14 September 1960.<ref name=OSTIV2/> |
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Its wings had an all wood structure and were mounted with 2.5° of [[dihedral (aircraft)|dihedral]]. They were significantly forward swept, by 7° at quarter [[chord (aircraft)|chord]], with a constant chord inner section and strongly tapered |
Its wings had an all wood structure and were mounted with 2.5° of [[dihedral (aircraft)|dihedral]]. They were significantly forward swept, by 7° at quarter [[chord (aircraft)|chord]], with a constant chord inner section and strongly tapered outer panels with unswept [[leading edge]]s. The wings were built around a single [[spar (aviation)|spar]] with a forward, [[plywood]] skinned torsion box between it and the leading edge; behind the spar the wing was [[aircraft fabric covering|fabric covered]]. The tips carried the small sreamlined bodies known as salmons, common at the time. The outer panels carried wooden slotted [[aileron]]s which were ply skinned but with an outer [[aircraft fabric covering|fabric]] covering.<ref name=OSTIV2/> |
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The IS-8 had an ovoid cross-section metal and plywood [[monocoque]] [[fuselage]]. Its [[tandem]] two seat [[cockpit]] stretched from just behind the nose to behind the wing leading edge, enclosed by a long, smoothly contoured [[perspex]] [[aircraft canopy|canopy]] which opened both to the side and to the rear. Between the wings the fuselage depth decreased rapidly, so that aft of the [[trailing edge]] it was quite slender. |
The IS-8 had an ovoid cross-section metal and plywood [[monocoque]] [[fuselage]]. Its [[tandem]] two seat [[cockpit]] stretched from just behind the nose to behind the wing leading edge, enclosed by a long, smoothly contoured, multipart [[perspex]] [[aircraft canopy|canopy]] which opened both to the side and to the rear. Unusually, the IS-8 had [[air brake (aircraft)|airbrakes]] not on the wings but on the fuselage sides under the wing, though Silimon had used this arrangement before on the pod and boom [[IIL IS-5]]. These were rectangular, each with an area of {{convert|0.37|sqm|sqft|abbr=on|1}}. Between the wings the fuselage depth decreased rapidly, so that aft of the [[trailing edge]] it was quite slender. The horizontal tail, mounted on top of the fuselage, was straight tapered in plan with squared tips and constructed in the same way as the ailerons. There were gaps at both ends of the [[elevator (aircraft)|elevator]]s, between the fin at the root and between a rearwards tailplane extension at the tip. The starboard elevator carried a [[trim tab]]. The ply-skinned [[fin]], positioned at the elevator hinge line, was narrow and mounted a fabric covered and largely straight [[balanced rudder|unbalanced rudder]] which reached down to the keel.<ref name=OSTIV2/> |
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The main landing gear was a fixed, unsprung [[undercarriage#Gliders|monowheel]] under mid-wing, at the point where the lower fuselage curved upwards toward its more slender rear. There was also a very short rubber sprung skid under the cockpit and a tail bumper.<ref name=OSTIV2/> |
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The horizontal tail, mounted on top of the fuselage, was straight tapered in plan with squared tips and constructed in the same way as the ailerons. There were gaps at both ends of the [[elevator (aircraft)|elevator]]s, between the fin at the root and btween a rearwards tailplane extension at the tip. The elevators carried [[trim tab]]s. raised a little above the fuselage on a [[fin]] [[fillet (mechanics)|fillet]] and The ply-skinned fin and fabric, [[balanced rudder|unbalanced rudder]] were straight edged, the latter reaching down to the keel.<ref name=OSTIV2/> |
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The IS-8 was preferred over the earlier two seat Silimon [[IIL IS-7]] glider as a production aircraft destined for Romanian clubs because of its comparative operational economy and maintenance simplicity.<ref name=JAWA62/> Some sources state that the IS-8 was not cleared for [[aerobatics]],<ref name=OSTIV2/> others that it served Rumanian clubs as an aerobatic aircraft as well as a trainer and solo aircraft.<ref name=JAWA62/> |
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The IS-5 had a short, rubber sprung skid under the cockpit and a fixed, unsprung [[undercarriage#Gliders|monowheel]] under the wing, fitted with a brake. There was also a small tail skid.<ref name=OSTIV2/> |
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The IS-7 was classed as semi-aerobatic.<ref name=OSTIV2/> Development of it ceased when it was decided that the [[IIL IS-8]], another Silimon designed two seater but with a smaller span, would be operationally simpler and more economical to run.<ref name=JAWA62/> |
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==Specifications== |
==Specifications== |
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==References== |
==References== |
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Revision as of 22:58, 15 January 2014
| IS-8 | |
|---|---|
| Role | Two seat sailplane |
| National origin | Romania |
| Manufacturer | Intreprinderea de industrie Locală (IIL) |
| Designer | Iosif Silimon |
| First flight | 14 September 1960 |
The IIL IS-8 was a two seat sailplane designed by Iosif Silimons and built in Romania in 1960. They served with Romanian gliding clubs.
Design and development
From about 1950 to his death in February 1981, Iosif Silimon was Romania's most prominent glider designer, his aircraft distinguished by his initials.[1] The IS-8, a two seat shoulder wing cantilever monoplane, first flew on 14 September 1960.[2]
Its wings had an all wood structure and were mounted with 2.5° of dihedral. They were significantly forward swept, by 7° at quarter chord, with a constant chord inner section and strongly tapered outer panels with unswept leading edges. The wings were built around a single spar with a forward, plywood skinned torsion box between it and the leading edge; behind the spar the wing was fabric covered. The tips carried the small sreamlined bodies known as salmons, common at the time. The outer panels carried wooden slotted ailerons which were ply skinned but with an outer fabric covering.[2]
The IS-8 had an ovoid cross-section metal and plywood monocoque fuselage. Its tandem two seat cockpit stretched from just behind the nose to behind the wing leading edge, enclosed by a long, smoothly contoured, multipart perspex canopy which opened both to the side and to the rear. Unusually, the IS-8 had airbrakes not on the wings but on the fuselage sides under the wing, though Silimon had used this arrangement before on the pod and boom IIL IS-5. These were rectangular, each with an area of 0.37 m2 (4.0 sq ft). Between the wings the fuselage depth decreased rapidly, so that aft of the trailing edge it was quite slender. The horizontal tail, mounted on top of the fuselage, was straight tapered in plan with squared tips and constructed in the same way as the ailerons. There were gaps at both ends of the elevators, between the fin at the root and between a rearwards tailplane extension at the tip. The starboard elevator carried a trim tab. The ply-skinned fin, positioned at the elevator hinge line, was narrow and mounted a fabric covered and largely straight unbalanced rudder which reached down to the keel.[2]
The main landing gear was a fixed, unsprung monowheel under mid-wing, at the point where the lower fuselage curved upwards toward its more slender rear. There was also a very short rubber sprung skid under the cockpit and a tail bumper.[2]
The IS-8 was preferred over the earlier two seat Silimon IIL IS-7 glider as a production aircraft destined for Romanian clubs because of its comparative operational economy and maintenance simplicity.[3] Some sources state that the IS-8 was not cleared for aerobatics,[2] others that it served Rumanian clubs as an aerobatic aircraft as well as a trainer and solo aircraft.[3]
Specifications
Data from The World's Sailplanes (1963), pp.198-9[2]
General characteristics
- Crew: One
- Length: 7.35 m (24 ft 1 in)
- Wingspan: 13.35 m (43 ft 10 in)
- Wing area: 15.45 m2 (166.3 sq ft)
- Aspect ratio: 11.5
- Airfoil: NACA 43015 inboard, NACA 43012A tip
- Empty weight: 220 kg (485 lb) equipped
- Gross weight: 400 kg (882 lb)
Performance
- Stall speed: 62 km/h (39 mph, 33 kn)
- Never exceed speed: 180 km/h (110 mph, 97 kn) placard, smooth air
- Rough air speed max: 140 km/h (87 mph; 76 kn)
- Aerotow speed: 120 km/h (75 mph; 65 kn)
- Winch launch speed: 85 km/h (53 mph; 46 kn)
- Maximum glide ratio: best, 23:1 at 85 km/h (53 mph; 46 kn)
- Rate of sink: 0.98 m/s (193 ft/min) minimum, at 70 km/h (43 mph; 38 kn)
- Wing loading: 25.8 kg/m2 (5.3 lb/sq ft)
References
- ^ Taylor, John W. R. (1981). Jane's All the World's Aircraft 1981-1982. London: Jane's Information Group. p. 586. ISBN 0710607059.
{{cite book}}: Cite has empty unknown parameter:|coauthors=(help) - ^ a b c d e f Shenstone, B.S.; Wilkinson, K.G. (1963). The World's Sailplanes. Vol. II. Organisation Scientifique et Technique Internationale du Vol à Voile (OSTIV) and Schweizer Aero-Revue. pp. 198–9.
- ^ a b Taylor, John W R (1962). Jane's All the World's Aircraft 1962-63. London: Sampson Low, Marston & Co. Ltd. p. 335.
{{cite book}}: Cite has empty unknown parameter:|coauthors=(help)