SS.4 | |
---|---|
![]() | |
The Ambrosini SS.4 | |
Role | Fighter |
Manufacturer | SAI-Ambrosini |
Designer | Sergio Stefanutti [1] |
First flight | 7 March 1939 |
Number built | 1 |
The SAI-Ambrosini SS.4 was an Italian fighter prototype developed in the late 1930s, featuring a canard-style wing layout and a pusher propeller. Development of the SS.4 was abandoned after the prototype crashed on its second flight. [1]
Sergio Stefanutti had already experimented with canard aircraft with the S.C.A. SS.2 and S.C.A. SS.3 Anitra ("Duck" [lower-alpha 1] ), light aircraft built by Stabilimento Costruzioni Aeronautiche at Guidonia (a new municipality and location of a large Italian air force base).
The single-seat SS.2 had a canard wing configuration, fixed undercarriage, and was powered by a two-cylinder Keller engine rated at 16 hp (11.93 kW).
The SS.2 first flew in 1935, and one of the two prototypes was converted into a two-seater with a larger 38 hp (28.34 kW) CNA II engine built by Compagnia Nazionale Aeronautica . This new aircraft first took to the air on 2 October 1937, and was officially revealed in Milan at an international air exposition; the small fixed-undercarriage SS.2 was sent to Ambosini's facilities at Passignano sul Trasimeno for evaluation.
The SS.3 Anitra had a span of 12.77 m (41.9 ft), and was 6.00 m (19.7 ft) long, with an overall height of 2.01 m (6.6 ft). With a 16 hp (12 kW) engine, it was capable of a maximum speed of 87 mph (140 km/h) and able to reach an altitude of 13,120 ft (4,000 m). Stalling speed was 34 mph (55 km/h): [1]
Experience with this machine and the study of its aerodynamics led Stefanutti to design a canard-style interceptor and air-superiority fighter, designated SS.4, very similar in layout to the SS.2 and SS.3. [1]
A prototype SS.4 was built at the Società Aeronautica Italiana - Ambrosini factory in Passignano sul Trasimeno, Umbria. The first flight took place on 7 March 1939, but during its second flight next day, the aircraft crashed, killing Ambrosini's chief test pilot Ambrogio Colombo. A second prototype was ordered, but development priority was placed on more easily developed wooden aircraft, and the SS.4 design was abandoned in 1942. [1]
The SS.4 was a single-seat fighter of all-metal construction with a canard configuration wing, with twin fins mounted on the wing trailing edges, retractable tricycle undercarriage, and short fuselage with a rear-mounted engine driving a pusher propeller. [1]
The pilot was accommodated in an enclosed cockpit in the centre of the fuselage forward of the two fuel tanks and aft of the armament in the nose. Visibility from the cockpit was excellent to the sides and front, but restricted to the rear by the large main wing, engine, and large twin fins positioned at roughly the half-span position. Flying controls consisted of elevators on the trailing edges of the canard fore-plane controlling pitch, rudders on the large fins controlling yaw, and ailerons on the main wings to control roll. Pitch trim was set by adjusting a trim tab on the starboard elevator. [1]
The moderately swept, tapered, high-aspect ratio wings had no sweep on the trailing edge and a cut-back to give clearance for the propeller, with the large fins with rudders extending past the trailing edge at the ends of the cut-backs, to ensure enough moment to give adequate control and stability. The delta fore-plane was of low aspect ratio with the elevators sited below the trailing edge similar to the method used by contemporary Junkers aircraft like the Junkers Ju 87. [1]
The engine was a powerful, liquid-cooled Isotta Fraschini Asso XI R.C.40 engine capable of 960 hp (720 kW) driving a three-bladed metal propeller. The engine was cooled by two radiators either side of the fuselage in ducts just behind the cockpit. Fuel for the engine was housed in two fuel tanks located mid-fuselage, along with an oil tank. [1]
Armament was to be two 20 mm (0.787 in) cannon and one 30 mm (1.181 in) cannon, clustered in the nose. [1]
The prototype SS.4 was built by SAI Ambrosini, Passignano sul Trasimeno, and then sent to nearby Eleuteri airport, Castiglione del Lago, also in the Trasimeno area. There, the aircraft was successfully flown for the first time on 7 March 1939. The next day, the SS.4 prototype was scheduled to be transported to Aviano airbase by rail, but Ambrosini's chief test pilot, Ambrogio Colombo, wanted a second test flight. After 45 minutes, an aileron malfunctioned just 2 km (1.2 mi) from Eleuteri. Colombo attempted to land, but was unable to reach the runway and crashed near Campagna, hitting a tree. [1] Colombo was killed when the engine pushed through the rear bulkhead and crushed him against the front of the cockpit.
A memorial to Colombo was erected near the site of the crash. The investigation into the crash concluded that the accident was due to imperfect construction, which led to a faulty installation of the aileron that had failed. The study also pointed out the excessive vibrations transmitted by the engine to the wing. [2]
Data fromItalian Civil and Military Aircraft 1930–1945 [1]
General characteristics
Performance
Armament
Aircraft of comparable role, configuration, and era
The Kyūshū J7W Shinden is a World War II Japanese propeller-driven prototype fighter plane with wings at the rear of the fuselage, a nose-mounted canard, and a pusher engine.
The Curtiss-Wright XP-55 Ascender (company designation CW-24 is a 1940s United States prototype fighter aircraft built by Curtiss-Wright. Along with the Vultee XP-54 and Northrop XP-56, it resulted from United States Army Air Corps proposal R-40C issued on 27 November 1939 for aircraft with improved performance, armament, and pilot visibility over existing fighters; it specifically allowed for unconventional aircraft designs. An unusual design for its time, it had a canard configuration with a rear-mounted engine, and two vertical tails at end of swept wings. Because of its pusher design, it was satirically referred to as the "Ass-ender". Like the XP-54, the Ascender was designed for the 1,800 hp Pratt & Whitney X-1800 24-Cylinder H-engine, but was redesigned after that engine project was canceled. It was also the first Curtiss fighter aircraft to use tricycle landing gear.
In aeronautical and naval engineering, pusher configuration is the term used to describe a drivetrain of air- or watercraft with its propulsion device(s) after its engine(s). This is in contrast to the more conventional tractor configuration, which places them in front.
The Rutan Quickie is a lightweight single-seat taildragger aircraft of composite construction, configured with tandem wings.
The Latécoère 570 was a twin-engined medium bomber designed to a 1934 specification. It did not fly until 1939, by which time competitor aircraft had gone into service.
The Mansyū Ki-98,, was a Japanese ground-attack aircraft proposed by Mansyū during World War II for use by the Imperial Japanese Army Air Force. The still unassembled components of the first prototype were deliberately destroyed before Japan surrendered.
The Latécoère 225 was an unusual single seat canard microlight amphibian, with a swept wing, and of pusher configuration. It first flew in 1984 but was not put into production.
The Ion Aircraft Ion is a two-seat, twin boom, pusher configuration light aircraft based on the DreamWings Valkyrie. It was still in development in 2010 but is intended either for homebuilding from kits or flyaway production, with versions meeting US and European rules.
The Savoia-Marchetti SM.80 is a two-seat monoplane amphibian tourer, with a single, tractor engine mounted above the wing, designed in Italy in the early 1930s. The SM.80bis is a four-seat variant, powered by two pusher engines.
The Siemens-Schuckert DDr.I was a World War I German twin engine, push-pull configuration triplane fighter aircraft. Only one was built, crashing on its first flight.
The Farner HF Colibri 1 SL was an unusual canard motor glider with a unique control system, designed and built in Switzerland in the late 1970s. Only one was constructed; much modified during the 1980s, it was still flying in 1990.
The Nieuport-Delage NiD 48 was a French single-engine parasol wing light fighter aircraft, designed and built in the 1920s. Its performance was not markedly better than that of the much heavier Nieuport-Delage NiD 62 then going into production, so only two were flown.
The Loire-Nieuport 161 was a single-seat, single-engine, all-metal, low-wing monoplane fighter designed and built in France in 1935 to compete for a government contract. Accidents delayed its development and only three prototypes were completed.
The Weymann W-1 was a French single seat biplane fighter aircraft, built during World War I. It had a most unusual layout, with an engine buried in the fuselage driving a pusher configuration propeller behind a cruciform tail. It was not successful and soon abandoned.
The Hanriot H.110 was an unusual pusher configuration, twin boom, single seat fighter aircraft built in France in the early 1930s. It proved to be slower and less manoeuvrable than its contemporaries and failed to reach production, even as the Hanriot H.115 after receiving a more powerful engine and cannon armament.
The Schütte-Lanz G.I was a large, twin engine, pusher configuration, experimental biplane built in Germany early in World War I. Only one was completed.
The Aviator Shershen' is a Russian two seat biplane, sold in kit form. It first flew in 2005 and several variants have been produced, with a choice of engines.
The Bonomi BS.22 Alzavola was a training motor glider, intended to acquaint capable glider pilots with the characteristics of powered aircraft. The sole example was designed and built in Italy in the mid-1930s.
The de Bruyère C 1 was a prototype French single seat pusher canard Fighter of unusual design produced during World War I. The sole example built crashed on its first flight, and development terminated.
The De Schelde S.21 was a proposed Dutch fighter of the late 1930s and early 1940s. It was a single-seat, single-engined, pusher monoplane. A single prototype was under construction in 1940, but work was abandoned due to the German invasion.