Alisport Silent 2
From Wikipedia, the free encyclopedia
Type designation | Silent 2 pure |
Competition class | FAI DU Class |
Number built | ca. 80 |
Crew | 1 |
Length | 6.35 m (20.8 ft) |
Height | 1.25 m (4.1 ft) |
Cockpit width | 0.63 m (2.1 ft) |
Cockpit height | 0.91 m (3 ft) |
Wingspan | 13.0 m |
Wing area | 8.9 m² (95.7 sq ft) |
Aspect ratio | 20.0 |
Wing profile | IMD 050 (16%) |
Empty mass | 130 kg |
Maximum mass | 300 kg (661 lb) |
Wing loading | 34 kg/m² (6.96 lb/sq ft) |
Maximum speed | 220 km/h (119 knots) |
Speed in rough air | 150 km/h (81 knots) |
Stall speed | 64 km/h (35 knots) |
Minimum sink rate | 0.60 m/s at 85 km/h (118 ft/min at 46 knots) |
Best glide ratio | 40 at 90 km/h (49 knots) 30 at 120 km/h (65 knots) 20 at 150 km/h (81 knots) |
Roll rate | 4 s at 80 km/h (43 knots) -45° to +45° bank |
The Silent 2 is a single seater sailplane of Italian manufacture. It is of the FAI type DU Class glider. It is sold by Alisport ready-to-fly or kit-built as pure glider or self-launching glider. The self-launching version is fitted with a single-blade propeller belt-driven by a two-stroke engine.
[edit] Design and construction
- The fuselage is carbon and glass fiber composite with epoxy resin.
- The wings have an elliptical planform, vertical or elliptical design winglets. The wing structure includes extensive use of carbon fiber, both in the sandwich skins and in the tapered I-beam wing spar which uses pultruded carbon rods for the spar caps.
- The wing geometry is notable in that it varies non-linearly from the root to the tip, both in overall planform shape and in wing section profile.
- The flaperons stretch for 11.0 meters of the full wingspan and their range of motion varies from positive landing L +8°, to +4° for thermalling, to 0°, -4°, and S -8° reflex positions for cruising.
- Schempp-Hirth-type spoilers extend on the upper wing surface only.
- Fixed main wheel behind the pilot, with shock absorber and drum brake activated via spoiler control lever aft travel.
[edit] Safety and operational qualities
- The Silent 2 has light ailerons, light elevator, generous rudder. The roll rate is quick because of the lively feel of the ailerons.
- Stall is predictable and recovery simple. In level flight as airspeed is reduced when approaching the stall speed the sailplane vibrate a little, at this point decreasing the angle of attack results in airspeed increase and normal flight resume, from a climbing attitude the sailplane stall decisively, the nose pitch down gently and recovery is easy with stick forward.
- Spin entry is obvious and recovered with rudder and stick.
[edit] Versions
There are three versions of the Silent Gliders.
The Silent Club version has 12 meter wingspan.
The Silent 2 version has 13 meter wingspan.
The Silent 2 Targa version 13.3 meter wingspan and a special elevator.