I-1

From OnAirpower.org

I-1

Designation:	I-1
Also Known As:	I1-M5
Manufacturer:	Polikarpov
Nationality:	Soviet
First Flight:	1926
Remarks:	The earliest indigenously designed Soviet fighter to enter series production, albeit with a relatively unsuccessful and short career
See Also:	IL-400, IL-400b

[edit] Notes

After the successful testing of the IL-400b prototype, series production of the design began in early 1926 with an order for 33 aircraft under the designation "I1-M5" (for first fighter type, equipped with the M-5 engine), later shortened to "I-1". The series produced aircraft differed from the IL-400b prototype in a number of ways, including the shape of the fuselage and the use of wood construction rather than the prototype's aluminum, a decision that was based on both the general shortage of aluminum in the USSR at the time as well as the need to speed up and simplify construction of the aircraft. The wings of the production aircraft were also strengthened based on the results of static testing, which increased the aircraft's weight and decreased its flight performance. As a result of the changes, the aircraft's center of gravity was shifted rearward, to 44% of mean aerodynamic chord, which resulted in even worse flight characteristics including poor handling during spins that were reminiscent of the failed IL-400 initial prototype^[1].

The changes between the prototype and series aircraft proved to be a significant problem. During testing of the production aircraft, pilot A. I. Sharapov nearly lost his life when he was unable to get the I-1 out of a spin. Pilot M. M. Gromov was also unable to get the aircraft out of a spin and was forced to abandon the aircraft and parachute to the ground. As a result of the deficiencies in the the I-1's performance, it was labeled as "dangerous for flight" and was not made operational. Only 18 of 33 aircraft that were originally ordered were produced^[1].