The SD-1 Specifications
Fuselage
The fuselage is of wood truss design using mainly 15x15 mm sections covered with plywood of 0,8-3 mm thickness. The pilot's seat back is inclined at 40 degrees. This provides comfortable headroom for a 185 cm (6,1 ft) tall pilot. The height of canopy may be modified for a taller pilot if necessary. The inside with of cockpit at shoulder height is 54 cm (21,3"). The plywood box tunnel with wing and upper gear legs mounts is under the pilot's knees. The baggage compartment of 40 l (1,5 ft3) is situated behind the removable seatback. A composite cockpit hood with a 2 mm thick polycarbonate windshield of opens to the side. The hood is lockable. A NACA inlet for ventilation is provides on the side of cockpit hood.
Wing
The two part wing uses the GA 37U-A315 airfoil. It consists of a composite main spar with carbon caps onto which are glued ribs made of extruded polystyrene. It is covered with 1 mm plywood. Wingtips are made either of extruded polystyrene with a fibreglass layup or as a pre-moulded vacuum bagged sandwich. The weight of a painted wing half is 12 kg (27 lbs). Connection of the of wings to the fuselage is made using two main and two auxiliary locking pins. Disassembly of wings takes 5 minutes and assembly 10 minutes. The connection of the flaperons to the controls is performed by simply inserting a control pin into a slot.
Tailplane
The all movable horizontal tailplane has an anti-servo tab and is statically balanced. The tailplane is of similar construction to the wings - polystyrene ribs and plywood skin attached to a composite spar. The spring bias trim is situated under the pilot's seat. Disassembly of the tailplane requires simply the disconnection of control and tab rods and pulling out of pin. The fin has a similar composite main spar with carbon caps.
Undercarriage
The main gear legs are made of pultruded fibreglass rods. The wheels are 12"x4" and are braked using mechanical drum brakes. A tail wheel of 100 mm (4") diameter is controlled via the rudder and is attached to a fibreglass spring. A tricycle undercarriage option is available.
Controls
The horizontal tailplane and flaperons are controlled via pushrods and bellcranks. The rudder is controlled via cables.
Engine
The prototype aircraft is powered by a Trabant auto conversion with 120x70 (48"x27.5") propeller fitted directly onto the crankshaft. The Trabant engine is good choice for SD-1 due to its robustness, high reliability, low consumption and cost.
Subsequent aircraft are being powered Hirth F-33 AS, F-23 AS and B&S Vanguard 22 HP engines. It is possible to use any engine of 22-50 HP power range up to 40 kg (89 lbs) weight. This provides many options e.g. Hirth 2702, Simonini Victor 1, 2SI 460 F, 1/2 VW etc.
Fuel system
The integral tank of 28 l (7.4 US gal.) capacity is placed behind fuselage firewall. It is made of fibreglass-PVC foam sandwich. The Mikuni pump is connected to the engine crankcase. An auxiliary electric pump is placed on the firewall.
Electrical system The electrical bus is powered by a battery and is charged by alternator integrated with the engine's electronic ignition. It is possible to place a 12 V socket under the instrument panel for GPS etc.
Instruments The airplane is fitted with basic flying instruments; ASI, altimeter, compass and VSI. The engine instruments measure RPM´s, total hours, head and exhaust gas temperatures. There is space for a COM transceiver with installed diameter of 57 mm in the instrument panel. The COM antenna is built into the airframe. A transponder could be placed on the cockpit floor.
Rescue System
The prototype airplane is equipped with a ballistic rescue system GRS 4/270. The system container is attached to the fuselage bulkhead behind pilot´s back. The front cables are attached to the upper engine mount lugs. The auxiliary cable is attached to the fuselage behind the cabin. It is possible to use other systems in production versions. If a light engine is used it is possible to mount the rescue system on the firewall. It is of course possible to built airplane without rescue system in countries where it is not mandatory for this class of aircraft.
Specification
The fuselage is of wood truss design using mainly 15x15 mm sections covered with plywood of 0,8-3 mm thickness. The pilot's seat back is inclined at 40 degrees. This provides comfortable headroom for a 185 cm (6,1 ft) tall pilot. The height of canopy may be modified for a taller pilot if necessary. The inside with of cockpit at shoulder height is 54 cm (21,3"). The plywood box tunnel with wing and upper gear legs mounts is under the pilot's knees. The baggage compartment of 40 l (1,5 ft3) is situated behind the removable seatback. A composite cockpit hood with a 2 mm thick polycarbonate windshield of opens to the side. The hood is lockable. A NACA inlet for ventilation is provides on the side of cockpit hood.
Wing
The two part wing uses the GA 37U-A315 airfoil. It consists of a composite main spar with carbon caps onto which are glued ribs made of extruded polystyrene. It is covered with 1 mm plywood. Wingtips are made either of extruded polystyrene with a fibreglass layup or as a pre-moulded vacuum bagged sandwich. The weight of a painted wing half is 12 kg (27 lbs). Connection of the of wings to the fuselage is made using two main and two auxiliary locking pins. Disassembly of wings takes 5 minutes and assembly 10 minutes. The connection of the flaperons to the controls is performed by simply inserting a control pin into a slot.
Tailplane
The all movable horizontal tailplane has an anti-servo tab and is statically balanced. The tailplane is of similar construction to the wings - polystyrene ribs and plywood skin attached to a composite spar. The spring bias trim is situated under the pilot's seat. Disassembly of the tailplane requires simply the disconnection of control and tab rods and pulling out of pin. The fin has a similar composite main spar with carbon caps.
Undercarriage
The main gear legs are made of pultruded fibreglass rods. The wheels are 12"x4" and are braked using mechanical drum brakes. A tail wheel of 100 mm (4") diameter is controlled via the rudder and is attached to a fibreglass spring. A tricycle undercarriage option is available.
Controls
The horizontal tailplane and flaperons are controlled via pushrods and bellcranks. The rudder is controlled via cables.
Engine
The prototype aircraft is powered by a Trabant auto conversion with 120x70 (48"x27.5") propeller fitted directly onto the crankshaft. The Trabant engine is good choice for SD-1 due to its robustness, high reliability, low consumption and cost.
Subsequent aircraft are being powered Hirth F-33 AS, F-23 AS and B&S Vanguard 22 HP engines. It is possible to use any engine of 22-50 HP power range up to 40 kg (89 lbs) weight. This provides many options e.g. Hirth 2702, Simonini Victor 1, 2SI 460 F, 1/2 VW etc.
Fuel system
The integral tank of 28 l (7.4 US gal.) capacity is placed behind fuselage firewall. It is made of fibreglass-PVC foam sandwich. The Mikuni pump is connected to the engine crankcase. An auxiliary electric pump is placed on the firewall.
Electrical system The electrical bus is powered by a battery and is charged by alternator integrated with the engine's electronic ignition. It is possible to place a 12 V socket under the instrument panel for GPS etc.
Instruments The airplane is fitted with basic flying instruments; ASI, altimeter, compass and VSI. The engine instruments measure RPM´s, total hours, head and exhaust gas temperatures. There is space for a COM transceiver with installed diameter of 57 mm in the instrument panel. The COM antenna is built into the airframe. A transponder could be placed on the cockpit floor.
Rescue System
The prototype airplane is equipped with a ballistic rescue system GRS 4/270. The system container is attached to the fuselage bulkhead behind pilot´s back. The front cables are attached to the upper engine mount lugs. The auxiliary cable is attached to the fuselage behind the cabin. It is possible to use other systems in production versions. If a light engine is used it is possible to mount the rescue system on the firewall. It is of course possible to built airplane without rescue system in countries where it is not mandatory for this class of aircraft.
Specification
*valid for plane equiped with Hirth F-33 AS (28 HP) engine, without rescue system
** Hirth F-33 AS engine
***Hirth F-33 AS engine and propeller 120x95 (48x37.4)
** Hirth F-33 AS engine
***Hirth F-33 AS engine and propeller 120x95 (48x37.4)
Copyright Spacek s.r.o. 2011