Here is more information on the Caproni Campini N.1, which at the time of its first flight in August 1940, was believed to be the first jet powered aircraft to fly. Later, it was disclosed that the German Heinkel He 178 made its first flight in secret in August 1939.
The N.1 motorjet used a 650 kW piston engine to power the compressor stage of its jet engine, which operated as an afterburner in the air flow from the compressor. Performance was unimpressive, with a maximum speed of 375 km/hour, with the heavy powerplant contributing to high fuel consumption.