M5

Grigorovich M-5 (alternative designation Shch M-5, sometimes also Shchetinin M-5) was a successful Russian World War I-era two-bay unequal-span biplane flying boat with a single step hull, designed by Grigorovich. It was the first mass production flying boat built in Russia. The aircraft designer Dmitry Pavlovich Grigorovich completed his first flying boat (the model M-1) in late 1913, and produced a series of prototypes, gradually improving the design, until the M-5 appeared in the spring of 1