The PWS-12 was a single-engined two-seat training biplane, fit also for aerobatics, designed in 1928 by A. Grzędzielewski and August Bobek-Zdaniewski at the PWS factory.
The design shared similar parts, including fuselage and engine, as a high-wing trainer fighter plane PWS-11, developed at the same time.
The main difference was the addition of a lower wing.
It was powered by a nose-mounted Skoda-built version of the Wright J-5 Whirlwind radial engine.
Two prototypes and an airframe for static tests were ordered by the Aviation Department of the War Ministry in February 1928 (along with the PWS-11 prototypes).
The first prototype was flown by Franciszek Rutkowski in November 1929.
It was later improved – among others, a Townend ring replaced NACA cowling, and it was fitted with N-shaped struts between wings instead of perpendicular struts.
The second improved prototype was flown on 18 November 1930, and designated PWS-12bis.
Testing was successful and a production order for 20 aircraft was placed by the Polish Air Force.
In a meantime, the factory developed improved model PWS-14, featuring a change from wooden to a steel-tube fuselage, strengthened wings and other improvements, like a door in first cockpit’s side.
The War Ministry ordered a production of one PWS-14 and a similar modification of the series being in production.
It caused some financial problems for the factory, since a production of PWS-12s had already started.
As a result, the factory delivered in 1932 a series of 20 PWS-14, marked officially as PWS-12.
A further development of PWS-14 was PWS-16, and then PWS-26.
Variants
PWS-12
Prototype of wooden construction.
PWS-12bis
Second improved prototype
PWS-14
Improved model of mixed construction
(Aircraft delivered to the Air Force were marked as PWS-12)