Staff Writer (Updated: 4/8/2016):
Giovanni Casiraghi designed the all-metal Piaggio P.108 based on the all-wood P.50. Casiraghi garnered valuable experience during his time as an engineer during the "Golden Age of Flight" while in the United States for nearly a decade (1927 to 1936). The initial model P.50 was a similar large, heavy bomber design with a four-engines set as a tandem "pusher/puller" arrangement along the wings. It appeared in 1937 and construction included two prototypes. The aircraft was not ordered into production by the Italian government. The P.50-II appeared in 1938 and sported four radial pistol engines in a more conventional "puller" layout. A single prototype was constructed but the type was also not ordered by the Italian powers. However, the design and the development of these large aircraft played a crucial role in bringing the upcoming P.108 to fruition. In a government-sponsored competition for a new modern bomber to serve the Regia Aeronautica, the P.108 design won out over its competitors.
From the outset, the P.108 was planned in four distinct versions requiring a flexible airframe. The P.108A "Artiglieri" would become a dedicated anti-shipping platform to protect Italian interests across the Mediterranean Sea - this model armed with an Ansaldo 1941 Model 90/53mm cannon and torpedoes for the job. The P.108B "Bombardiere" would become the dedicated workhorse and heavy bomber platform of the Regia Aeronautica. The P.108C "Civile" was to be a 32-seat civilian passenger airliner while the P.108T "Transporto" was to become its militarized transport form - serving up to 56 combat-ready troops.
In the end, only one promising (and tested) P.108A was produced due to Italian priorities. However, quantitative production was seen out of the P.108B, P.108C and P.108T types but the Bombardiere remained the notable production model in the P.108 family. The P.108M "Modificato" was to be a modified P.108B with improved armament but this was never built. The P.133 was another proposed advanced version of the P.108 with better engines and an improved bomb load but this was never completed. One of the more unique design elements of the P.108 bomber version was its use of remote-controlled machine gun mounts fitted to the trailing end of each outer engine gondola to help protect the aircraft against attacks from the rear - an unproven and novel concept at best.
The prototype P.108 achieved first flight on November 24th, 1939. However, the P.108 in its operational form would not be delivered to the Regia Aeronautica until May of 1941. Technical difficulties in the advanced design also delayed the P.108B for another year before being deployed with the 274th Long Range Bomber Squadron. Furthermore, a general lack of government and industry support of the P.108B model in particular helped to diminish her possible wartime success. Just 163 total P.108 examples of all variants were completed by the time production stopped in 1943. The P.108C and P.108T models proved the more reliable aircraft in the end.
The P.108 in Action
The P.108 proved an innovative bomber aircraft for her time and could match the strongest qualities of her Allied contemporaries. Of particular note were her advanced wings and their integrated turrets - innovative yet overly complex and questionable in their implementation into the final design. Unfortunately for the Regia Aeronautica, there were never more than seven or eight P.108s available at any one time. To add insult to injury, the P.108 proved a poor-handling bomber design once in practice and engine reliability soon took its toll. The models that were airworthy saw action over the Mediterranean Sea, though mostly concentrated during the span of 1942 and 1943 before the Italian surrender. The Piaggio P.108 was used in nighttime raids on Allied ports based in Algeria and Gibraltar during the Operation Torch landings. Operation Torch was launched in November of 1942 and was the first major Allied operation to include quantitative military forces from America - the operation began the Allied campaign across French North Africa in an effort to take away Italian and German staging areas on the African continent. In all, there were 55 recorded bombing sorties involving the P.108B with last actions being seen over Sicily.