Alisport Silent 2

From Wikipedia, the free encyclopedia

Silent 2
A Silent 2 with elliptical winglets.
A Silent 2 with elliptical winglets.
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.