- For the construction of the fuselage : no millings or specific
turnings of parts, neither bendings of tubes; only straight stainless
steel tubes, welded under neutral gas (T.I.G.).
Time needed for building the fuselage : approximately 100 hours (no
special competence nor special tools needed).
- For the construction of the wings : no complicated jigs or flat
tables. No dihedral or sweep angles to worry about. No cables or
internal rods, no hinges, no flaps nor ailerons, no upper struts, no
sewing of fabrics, no (or just a few) handling of dangerous and/or
harmful products and materials.
Time needed for building the wings : approximately 100 hours (no special
competence nor special tools needed).
- For the motorization used : no special adaptation or changes to
original stock configuration; no gearbox or belt reduction, no mixture
of fuel with the four-stoke engine used; very few vibrations and
noise(the exhaust muffler is integrated into the fuselage base tube);
and this industrial engine is very reliable, with low maintenance needed.
- For piloting ("driving !)" : only a throttle and steering wheel. No
pedals or othercontrols and accessories.
2) THE SAFEST OF ALL AIRCRAFT :
- Landing, taxiing and ground handling : with a low and rearward center
of gravity, a wide and long wheel base, and the fuselage acting as a
skid, associated with effective shock absorbers, large diameter wheels,
safe placement of the placement of the pilot's feet, a powerful front
wheel brake, a rigid seat equipped with "4 points" safety belts, a
head-rest, an electric starter, a propeller well protected from rocks
and debris, as well as from bystanders, an overhead wing to avoid
obstacles, a deformable fuselage in the event of accident, well
triangulated to insure the safety of the pilot.
- In flight safety : all the exceptional advantages of the "Spratt"
aerodynamical formula used (no stall nor spin, and the aerodynamic
absorption of gust loads), maximum visibility in all directions due to
the high wing and the pusher engine, good gliding ratio due to a low
drag design, very few vibrations and noise, no icing carburettor in this
engine configuration, great autonomy (6 hours) in spite of the small
fuel quantity (25 liters tank, with directly visible fuel level), small
maximum mass and low landing speed limiting eventual damage.
3) MOST ECONOMIC OF ALL AIRCRAFTS:
- Due to its very short construction time and the low cost of the
specific materials used.
Fuselage : uses stainless steel tubes of standard size and quality,
welded TIG. Other parts, such as the seat, wheels, fuel tank, baggage
container,"Heim" bearing joints, and other accessories can be found in
standard hardware distribution stores.
The total for fuselage construction parts costs approximately 800 $ / euros.
Wings : wingspars are made out of square aluminium tubes of ordinary
dimensions and standard quality, extruded polystyrene (styrofoam) ribs,
fiberglass fabric and coating, fixed and simple rudder.
The total for wing construction parts costing around 400 $ / euros.
Engine : 4 stroke, 25 hp, of industrial type with electric starter.
Propeller, battery and other accessories "off the shelves" items.
The total of motorization parts costing approximately 2 300 to 3 300 $ /
euros (depending on where you buy the engine...).
That means a total cost of maximum 4 500 $ / euros, according to the
invoices related to the first prototypes.
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- Moreover, this aircraft is conceived to resist bad weather. Since it
can occupy a space of only 4 m X 1 m X 1,20 meters (folding down in less
than 30 minutes), the "Spratt 103" will have very low expenses to
shelter it.