The three-engine formula, much developed by Italian manufacturers, had another noteworthy representative in the CANT Z. 1007, the bomber that, together with the SM.79 and BR.20, constituted the Regia Aeronautica’s standard equipment during the conflict. A total of 560 aircraft were built in three production series from 1939 to 1943. The Alcione was widely used on all fronts, proving to be an effective aircraft, despite the emergence of problems of structural weakness in extreme climates, such as Africa and Russia, due to its being built entirely of wood.
The project was launched in 1935 with the first prototype flying on 3/11/37. However, flight tests did not produce the expected results. This was due, above all else, to the engines, 3 Isotta-Fraschini Asso XI liquid-cooled engines driving two bladed wooden propellers, that proved incapable of generating their rated power of 840 hp. With the aim of improving the aircraft’s performance, a series of modifications were carried out, including the introduction of a three bladed Alfa Romeo metal propeller. The first production series consisting of 34 aircraft was characterized by the installation of anular-type frontal radiators. Nevertheless, the problems concerning the lack of reliability of the engines remained virtually unsolved in the aircraft that were built from 2/39-10/39. The problem was so great that the evaluation tests, carried out mainly by units of the 16th Stormo based in Venice, advised against the Z.1007’s being used operationally.
In the meantime, the design had been completely reworked, incorporating three 1,000 hp Piaggio IX radial engines. The new prototype, called the Z.1007bis, first flew in 1938 and was substantially modified as compared to its predecessor. Apart from the engines, the cross-section of the aircraft had been enlarged and completely reworked, while the overall dimensions had been increased. Other changes regarded the defensive positions on the back and belly and the tail planes, characterized by lower horizontal empennages. In the course of production, the Series I-III of the Z.1007bis had a single rudder and fin while the Series IV-IV had twin fins and rudders. The effectiveness of the changes became apparent during flight-testing and official evaluations carried out on 8 pre-series aircraft. The Z.1007bis proved to have a maximum speed of 283 mph at an altitude of 15,100 ft, a range of 1,242 miles and a maximum ceiling of 27,630 ft. The crew consisted of 5: a pilot, a co-pilot, a radio operator/gunner, a tail gunner and a gunner that operated either of the beam guns. Defensive armament consisted of 2-12.7mm machine guns in ventral and top turrets and 2-7.7mm machine guns in beam positions. The Z.1007bis had a maximum bomb load of 2,646 lbs of bombs or 2 17.7-inch torpedoes.
The final version was the Z.1007ter, of which only 35 were produced and which appeared in early 1943 using the Piaggio P.XIX radial engine that gave the Z.1007ter a top speed of 304 mph and a ceiling of 32,890 ft.
Deliveries of the Z.1007bis to the units commenced in the spring of 1940 to the 106th and 107th Groups of the 47th Stormo, although none could be considered operational when Italy entered the war in 6/40. The Z.1007’s first mission occurred in 9/40 when several of the single fin types were incorporated into the unit sent to Belgium to bomb England. It was not an outstanding debut as the CANTs carried out only a few missions on the English Channel front and with little success.
However, in 10/40, the Z.1007 was largely used in the invasion of Greece, followed by service in the Mediterranean, North Africa and especially against Malta. On the Russian front, the use of the three engine bombers was sporadic and intermittent. At the time of the armistice, the few remaining Z.1007’s were split about evenly between the pro-Axis and Co-Belligerent air forces. At its height, the Z.1007 was used by 4 Stormos, 7 Groups and 2 squadrons.
Article by JDG
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