Hi guys,
looking for historical search and manuals,
I can put in here only a few photos found.
Her story resumed:
The Piaggio P.111 was an unconventional high altitude aircraft, built in prototype form. She was included in Piaggio's 1937 stratospheric flight studies program.
Developed wasstarted in 1937 by Eng. Casiraghi, and on April 18, 1939 construction began at Cantieri Aeronautici Piaggio, Finale Ligure. The maiden flight taking place on April 9, 1940 (some source reported 1941 but probably wrong) with military serial number (Matricola Militare) 465 assigned.
The P.111 was an all metal twin engines low wing monoplane, with a compact and well proportioned configuration. A few main problems were encountered and brilliantly resolved: cabin pressurized engine feeding and profile of propellers for high altitude flying.
General features:
Power plant: 2 air cooled Piaggio XXI RC 100 (restablishing high 10.000mt !) radials each giving 1.000 HP at 32.800 Ft driving three blades Piaggio variable pitch props; Crew 3;
Dimensions: Wing span 18,0 mt; lenght 12,1 mt.; hight (gear down) 3 mt. (data not confirmed); Wing area 40,0 mq; Weight (empty) 4.580Kg, full loaded 6,530 Kg. Performances: minimum speed (low lev) 145 Km/h; Max speed at 10.000 Mt 580 Km/h; cruising speed (9/10 power) 550 Km/h; Rage at 10.000 Mt and cruising 1500 Km.
The info gained with P111 experiences was later utilized in the design of Piaggio 108C (commercial variant). The realization of the experimental prototype preluded to the designing of a civil aircraft to be employed on trans-oceanical flight. In 1935, similar studies were conducted in the US terminated with the construction of Boeing 307 S (stratospheric).
The relevance of aircraft capable of trans-continental flights couldn't have been missed by italian designers at a time when Italy was among the nations at the vanguard in aeronautic progress despite her industrial vulnerability.