Aviation of World War II

P.111 - an experimental aircraft with a pressurized cockpit, it was an aerodynamically clean twin-engine low-wing aircraft of an all-metal structure (only the steering surfaces had a linen covering on a metal frame) with a retractable landing gear with a tail wheel. The leading edge of the aircraft wing closer to the tips was equipped with fixed slotted slats.

The aircraft was powered by the new Piaggio P.XII RC Tornado 18-cylinder two-row radial air-cooled engines in a special high-altitude version 100 / 2V with two-stage centrifugal superchargers, which allowed to maintain the power of 1000 hp. (735 kW) up to an altitude of 10,000 m. The engines rotated three-bladed propellers of variable pitch Piaggio P.4003.

The almost cylindrical sealed cabin was riveted from thick duralumin sheets (the joints were caulked); it had narrow laminated glass windows and a round entrance hatch on the left side. The cockpit housed a crew of three. The seats of the two pilots (the right one also served as a navigator and radio operator) were located side by side, and in the depths of the cockpit was the seat of an operator technician who monitored the instrumentation.

A small-displacement gasoline engine with a piston compressor was installed in the nose of the aircraft to pump air into the cockpit. The pressurized cockpit was equipped with a water and carbon dioxide trap and was electrically heated, and the crew had oxygen cylinders and breathing masks for an emergency. The aircraft was also equipped with compressed air cylinders for emergency pressurization.

The high-altitude bomber was never created, nor was the passenger R.108S built; on the basis of the project of the latter, the military transport P.108T was developed, produced in a small series, but it did not have a pressurized cabin.

The prototype P.111, which received the military register number M.M.465, in addition to the main research program, was also involved in testing a high-altitude version of the Piaggio P.XI RC 60/72 14-cylinder radial two-row engines, less powerful than the P.XII. In total, before the military and economic collapse of the country, he managed to perform 110 test flights. At the beginning of 1943, the prototype was removed from the Air Force lists and returned to the manufacturing company, which also did not find use for it and in the spring of the same year was scrapped.

Photo	Description
	Drawing Piaggio P.111

Bibliography

• Piaggio P.111 Experimental High-Altitude Plane / Alternative History. Ivan Byakin /
• Piaggio P.111 light high-altitude bomber / Andrey Krumkach /

April 29, 2020.
In 1938, the command of the Italian Royal Air Force (Regia Aeronautica) commissioned Piaggio to develop a high-altitude long-range twin-engined three-seat bomber capable of operating at altitudes of about 10,000 meters. The chief designer of the company, Dr. Ing. Giovanni Casiraghi, decided to start with building a small twin-engine experimental aircraft and work out all the design features of pressurized cabins on it.
The modern high-altitude aircraft system, in addition to the air conditioning system, pumping warm air into the aircraft cabin, has an automatic pressure control system that maintains a constant pressure drop. Judging by the primitive air injection system - a gasoline engine - an air blower and emergency cylinders, there was no question of any SARD on the P.111 aircraft either, but the simplest exhaust valves that maintain a given pressure drop probably should have been ...

P.111 cockpit