The Fiat CR.42 Falco jet, powered by a Fiat A.74 RC38 14-cylinder radial engine with 840 horsepower, had a top speed of 274 mph. However, compared to other fighter planes of the time, such as the Hurricane, Messerschmitt, and Spitfire, its top speed was not impressive. The one-off version CR.42DB was able to reach 323 mph, which still holds the Guinness record for being the fastest biplane ever.

Despite being a biplane, which was considered obsolete during that period, Rosatelli, the designer of the Falco, introduced some advanced aerodynamic modifications. One notable change was the smaller size of the lower wing, which made the plane more agile and difficult to hit.

However, there were some questionable design choices as well. The Falco was built to be light, weighing less than 4,000 pounds. But this was achieved by excluding features such as armor and a working radio, which meant that pilots had no means of communication or coordinating attacks.

Furthermore, the early versions of the plane were armed with only two forward-facing Breda SAFAT machine guns, which were effective against older, wood and canvas-covered planes from World War I. However, they were not as effective against the more advanced armor and metal used in the newest fighter aircraft.

Despite these limitations, a total of 1,819 Falco jets were built between 1939 and 1944. While the majority were used by Italy, other countries like Croatia, Germany, Hungary, Sweden, Belgium, and Spain also operated them. One notable achievement was when a Luftwaffe-piloted Falco shot down a P-38 Lightning over Croatia in February 1945, possibly marking the last biplane victory. Today, only four surviving Falco jets are known to exist.