Supermarine S.4
An advanced monoplane racer, developed by
the British for the 1925 Schneider trophy race, was the Supermarine S-4.
The Schneider race was an international event for seaplanes. The S-4 is
a beautiful, highly streamlined, cantilever monoplane mounted on twin
floats. The wing, constructed of a wooden framework covered with
plywood, employed flush radiators that were not of the skin type. The
wings had landing flaps that could be geared to the ailerons. The rear
of the fuselage was of wooden semimonocoque construction, and the
forward portion containing the engine was of metal.
The engine had 12 cylinders arranged in 3
banks of 4. The engine gave the appearance of the letter "W";
accordingly, this cylinder arrangement was referred to as a W-type
engine. The characteristics of the aircraft contained indicates a drag
coefficient of 0.0274, which must be considered quite low in view of the
large amount of surface area of the exposed twin floats. The wing
loading of about 23 pounds per square foot was high for the period and
accounts for the use of the wing trailing-edge flaps.
Another important factor that allowed the
use of such a high wing loading was the relatively long take off and
landing runs possible with the use of rivers and harbours, as compared
with the confined land airfields of the day. The aircraft was destroyed
by wing flutter before the 1925 Schneider trophy race. The ailerons on
the S-4 were unbalanced, which no doubt contributed to the onset of wing
flutter at the high speeds of which the aircraft was capable. Flutter
and divergence of cantilever monoplane wings were not understood at that
period in the development of aeronautical technology.
Later Supermarine racers, which were quite
successful in subsequent. Schneider trophy competitions, employed the
more predictable wire-braced monoplane wings. The designer of the
Supermarine S-4, R. J. Mitchell, later designed the famous Spitfire
fighter of World War II.
Design Company: |
Short Brothers (Rochester &
Bedford) Ltd |
First Flight: |
4 May 1927 |
Crusader: |
1 - Short, Rochester |
Type
Specification |
Applies to: |
Short Crusader |
Type: |
Racing seaplane
|
Wing: |
Low wing monoplane. Wings
of nearly elliptical plan with maximum chord and thickness at half
span with bracing wires to fuselage and floats. Wings of wooden
construction |
Fuselage: |
Fuselage of circular
section is of wooden construction aft of cockpit and metal
construction forward |
Tail Unit: |
Cantilever monoplane tail
attached to fuselage with single fin and rudder |
Landing Gear: |
Twin single step floats of
metal construction |
Power Plant: |
One 808 hp Bristol Mercury
I 9 cylinder, single row, air cooled radial engine in nose |
Accommodation: |
Single seat for pilot in
open cockpit at wing trailing edge |
Dimensions |
Span: |
26 ft 6 in |
Length: |
25 ft |
Height: |
Unknown |
Wing Area: |
120 sq ft |
Weights |
Empty: |
1,938 lb |
All-up: |
2,712 lb |
Performance |
Max Speed: |
270 mph |
|
|