Air Pictorial 1957-08
H.Volker - The Irbitis Line
The Irbitis I-1 "Spriditis", powered by a 25-h.p. three-cylinder Anzani engine
The I-2 "Ikars" two-seater, powered by a 45-h.p. Anzani;
The I-9 was based on the experience gained with the I-5.
Te Irbitis I-4.
The I-5 was developed from the I-2, but was powered by a 77-h.p. Siemens & Halske Sh.5 engine;
The I-18 developed from the I-8.
The I-6 had folding wings with considerable sweep-back;
The I-8 was stressed for aerobatics and was powered by an Armstrong Siddeley "Genet" engine.