M-4, Sch-4, D.P.Grigorovich, Schetinin

40k photo from "History of aircraft construction in the USSR", Vol.1 p.138;

Flying boat, development of the M-3. Almost same fuselage, new wing airfoil. Tailplane angle could be adjusted by the pilot in flight. Performance improved, and M-4 was accepted by the Sea Department after flight tests in Sevastopol (1915).

Four built, two served on Baltic Sea, two on Black Sea.

Predecessor(s):	Modification(s):
M-3 Sch-3	M-5 Sch-5

• "History of aircraft construction in the USSR", Vol.1 p.159;