In the summer of 1938, the Latvian aircraft designer Kārlis Irbītis, working at the Valsts Elektrotehniskā Fabrika (VEF) at Riga commenced design of a single-seat advanced trainer as a follow on to his earlier, similar VEF I-14 aircraft.

 

The I-15 was a low-winged monoplane of all-wooden construction, powered by a single de Havilland Gipsy Six air-cooled engine, and fitted with a fixed tailwheel undercarriage.

 

The design of the I-15 was in general similar to the earlier I-14, but it was carried out taking into account the requirements of the Air Force of Latvia. The fuselage and wing were slightly redesigned, a new de Havilland Gipsy Six-I engine (200 hp) was installed with a two-bladed fixed-pitch wooden propeller.

 

 

 

In April 1939, the first prototype, the I-15a with the registration number "190", made its maiden flight, while a second prototype, the I-15b ("191"), was powered by a 220 hp (167 kW) Gypsy Six II engine driving a variable-pitch propeller, and armed with a single synchronised machine gun followed, this demonstrating improved performance, increasing speed from 314 to 330 km / h.

The two I-15 prototypes were transferred to the Latvian Air Force for use as advanced trainers, while a further two aircraft, to be designated I-15bis and powered by Hispano-Suiza 6 Mb engines were ordered by the Air Force, but on 17 June 1940, the Soviet Union occupied Latvia, ordering all aviation related work to be stopped.

 

Work on I-15 was discontinued in 1940, when a more advanced I-16 fighter was successfully tested.

 

Engine: 185/200-hp de Havilland Gypsy 6-I

Prop: 2-blade wooden propeller

Max Speed: 314 km/hr

 

Engine: 1 × de Havilland Gipsy Six Series II, 160 kW (220 hp)

Prop: DH constant speed, variable pitch metal

Wingspan: 8.00 m (26 ft 3 in)

Wing area: 10.77 m2 (115.9 sq ft)

Length: 7.10 m (23 ft 4 in)

Height: 2.10 m (6 ft 11 in)

Empty weight: 750 kg (1,653 lb)

Gross weight: 960 kg (2,116 lb)

Maximum speed: 331 km/h (206 mph; 179 kn)

max continuous Cruise speed: 300 km/h (186 mph; 162 kn)

Range: 610 km (379 mi; 329 nmi)

Service ceiling: 7,000 m (23,000 ft)

Armament: 1× machine gun

Crew: 1