Caproni Campini N.1

https://en.wikipedia.org/wiki/Caproni_Campini_N.1

The Caproni Campini N.1, also known as the C.C.2, was an experimental jet
aircraft built in the 1930s by Italian aircraft manufacturer Caproni. The N.1
first flew in 1940 and was briefly regarded as the first successful jet-powered
aircraft in history, before news emerged of the German Heinkel He 178's first
flight a year earlier.

During 1931, Italian aeronautics engineer Secondo Campini submitted his studies
on jet propulsion, including a proposal for a so-called thermo-jet to power an
aircraft. Following a high-profile demonstration of a jet-powered boat in
Venice, which was the world's first vehicle to harness jet propulsion, Campini
was rewarded with an initial contract issued by the Italian government to
develop and manufacture his envisioned engine. During 1934, the Regia
Aeronautica (the Italian Air Force) granted its approval to proceed with the
production of a pair of jet-powered prototype aircraft. To produce this
aircraft, which was officially designated as the N.1, Campini formed an
arrangement with the larger Caproni aviation manufacturer.

The N.1 was powered by a motorjet, a type of jet engine in which the compressor
is driven by a conventional reciprocating engine. It was an experimental
aircraft, designed to demonstrate the practicality of jet propulsion. On 27
August 1940, the maiden flight of the N.1 occurred at Caproni facility in
Taliedo, outside of Milan, flown by renowned test pilot Mario de Bernardi.
Subsequent flight tests with the first prototype led to a maximum speed of
roughly 320 MPH (515 km/h) being recorded. On 30 November 1941, the second
prototype was flown by pilot De Bernardi and engineer Giovanni Pedace from
Milan's Linate Airport to Rome's Guidonia Airport, in a highly publicised event
that included a fly-past over Rome and a reception with Italian Prime Minister
Benito Mussolini. Testing of the N.1 continued into 1943, by which point work on
the project was disrupted by the Allied invasion of Italy.

The N.1 achieved mixed results, while it was perceived and commended as a
crucial milestone in aviation (until the revelation of the He 178's earlier
flight), the performance of the aircraft was underwhelming; specifically, it was
slower than some existing conventional aircraft of the era, while the motorjet
engine was incapable of producing sufficient thrust to deliver viable
performance levels to be used in a fighter aircraft. Campini embarked on further
projects (like the Reggiane Re.2007), but these would involve the
indigenously-developed motorjet being replaced with a German-provided turbojet.
As such, the N.1 programme never led to any operational combat aircraft, and the
motorjet design was soon superseded by more powerful turbojets. Only one of the
two examples of the N.1 to have been constructed has survived to the present
day.

Design

The Caproni Campini N.1 was an experimental aircraft, designed to demonstrate
the practicality of jet propulsion and its viability as an engine for aircraft.
In terms of its basic configuration, it was composed entirely out of duralumin
and had a monoplane layout, being outfitted with an elliptical wing. The initial
aircraft lacked elements such as a pressurised cabin; however, these
improvements were featured on the second prototype. However, flight testing
quickly revealed that, due to the excessive heat output of the pioneering
propulsion system, the canopy would have to be left permanently open as a
mitigating measure.

The engine of the N.1 featured a radical design, differing substantially from
the later-produced turbojet and turbofan engines. One crucial difference in
Campini's design was the compressor – a three-stage, variable-incidence one,
located forward of the cockpit – was driven by a conventional piston engine,
this being a 900 hp (670 kW), liquid-cooled Isotta Fraschini unit. The airflow
provided by the compressor was used to cool down the engine prior to being mixed
with the engine's exhaust gases, thus recovering most of the heat energy that in
traditional piston-propeller designs would be discharged overboard. A
ring-shaped burner would then inject fuel into the gas flow and ignite it,
immediately before the exhaust nozzle, to further increase thrust.

In practice, the engine was able to provide sufficient thrust for flight even
without activating the rear burner, making the design somehow similar to a
ducted fan coupled with an afterburner. Campini referred to this configuration
as being a thermojet, although it has since become commonly known as motorjet.
However, despite the elaborate design, the relatively small size of the duct
limited the mass flow and thus the propulsive efficiency of the engine. In
modern designs this is offset through high overall pressure ratios, which could
not be achieved on the N.1, therefore resulting in relatively low thrust and
poor fuel efficiency. Ground tests performed with the static testbed produced a
thrust of around 700 kgf (1,500 lbf).


Role
Experimental aircraft

National origin
Italy

Manufacturer
Caproni

Designer
Secondo Campini

First flight
27 August 1940

Status
Prototypes only

Primary user
Regia Aeronautica

Number built
2

Developed into
Caproni Campini Ca.183bis

On 27 August 1940, the maiden flight of the N.1 occurred at Caproni facility in
Taliedo, outside of Milan. It was performed by test pilot Mario De Bernardi, an
accomplished aviation figure who had previously been responsible for setting
several world records in seaplanes and aerobatic aircraft; he would go on to
conduct the majority of the N.1's test flights. This initial flight lasted for
ten minutes, during which De Bernardi deliberately kept the speed of the
prototype below 225 MPH, less than half throttle, due to doubts surrounding the
untested airframe's ability to withstand the potentially high loading that it
would be subject to when flown at high speeds. Since the first flight of the
jet-powered Heinkel He 178, a year before to the day, at the time had not yet
been made public, the Fédération Aéronautique Internationale recorded the event
as the first successful flight by a jet aeroplane.

Subsequent flight tests with the first prototype led to a maximum speed of
roughly 320 MPH being recorded. However, testing revealed several issues with
the engine; particularly the determination that it lacked the ability to produce
sufficient thrust to achieve high performance if it were to be matched to a
strengthened airframe to withstand the high loading pressures. One of the more
unusual issues to be encountered during the flight test programme was the
considerable amount of engine heat which was conveyed into the cockpit; in order
to fly the aircraft, the crew were forced to keep the canopy open throughout the
flight, which effectively vented the heat. There were a few shortcomings,
however the overall results of the first flight were positive.

The experience gained from the N.1 proved influential to Campini. Having formed
a partnership with another Italian aircraft company, Reggiane, and aircraft
designer Roberto Longhi, he commenced work on an entirely new design; this would
have represented a significant departure from the N.1, including the decision to
abandon the indigenous Italian engine it used in favour of a German-provided
counterpart. This aircraft, the Reggiane Re.2007, was envisioned to be a
combat-capable fighter, unlike the purely experimental N.1. Campini would go on
to work on a number of jet-powered aircraft, including the Boeing B-47
Stratojet.

Testing of the two N.1 prototypes continued into 1943, however the programme was
heavily hindered by events of the Second World War, specifically the extensive
Allied invasion of Italy which would see the collapse of the nation's Fascist
government. During an Allied bombing attack on Caproni's factory in Taliedo, one
of the experimental aircraft was destroyed. After the conflict had reached its
end in 1945, one of the remaining prototypes was transported to the United
Kingdom for study at the Royal Aircraft Establishment (RAE) in Farnborough. This
aircraft was subsequently lost and its whereabouts have remained unknown.

Specifications

General characteristics
Crew: 2
Length: 13.1 m (43 ft 0 in)
Wingspan: 15.85 m (52 ft 0 in)
Height: 4.7 m (15 ft 5 in)
Wing area: 36 m2 (390 sq ft)
Empty weight: 3,640 kg (8,025 lb)
Max takeoff weight: 4,195 kg (9,248 lb)
Powerplant: 1 × Isotta Fraschini L.121 R.C.40 motorjet (670 kW (900 hp)
engine-driven three-stage, variable-pitch axial compressor with afterburner)

Performance
Maximum speed: 375 km/h (233 mph, 202 kn)
Service ceiling: 4,000 m (13,000 ft)




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