Aircraft KPI-5

In 1905 an aviation section was organized at the Kiev Polytechnic Institute under the initiative of Nikolai Artem'ev (1870-1948). Such was the amount of activity, that this became the second most important aviation development centre in Russia. Various notable persons eventually worked in this KPI section: Aleksandr Kudashev created and tested the first aircraft there (1910), also famous designers Dmitri Grigorovich and Igor Sikorskiy, along with D.L. Tomashevich, F.F. Tereshenko, V.P. Grigor'ev, the Kasyanenko brothers, and many others.

With the beginning of the First World War came the idea to manufacture military aircraft. The idea of a super-maneuverable fighter with a semi-monocoque fuselage, this featuring variable-incidence main wings for controlling flight, became a topic of much debate and conversation amongst the young engineers. Many submissions of various aerodynamic components were reviewed and rejected for the future design until Andrey Kasyanenko's "winged torpedo" design was accepted. The aircraft indeed looked like a torpedo, and was so named ("torpedo", the official designation being KPI-5).

The KPI-5's fuselage was a round structure of elongated teardrop shape featuring a slightly blunted nose profile and a very sharply tapered tail. The widest section of the fuselage was situated at 40% of the overall length, which in total was 7.0 meters. The area of the widest point, 0.725m2, was equal to that of the diameter of the Gnome Monosupape (sp?) (Width = 0.95 m). The placement of the motor was designed to allow the pilot the maximum view forward (who was seated in the nose of the fuselage), and with the best vantage point to aim the machine gun. In the extreme nose was mounted an English "Browning" gun (in fact, the gun was certainly a Lewis, and featured a large circular magazine; the name in the original documents is an error) with a 47-round drum magazine of 7.71 mm (sic) caliber. The gun could traverse in a limited arc by the pilot. The magazine could be changed only on the ground, as it was necessary to remove the nose cover of the fuselage to access it. The aiming method for firing the gun was thought to be similar to that used by American Cowboys, namely to `shoot from the hip'.

The fuel cell was situated between main former numbers 4 and 5. Aft, a crankshaft was attached to former number 6, which held the Monosopaupe (sp)? For the purposes of cooling, and also to draw air for the carburetor, small rectangular scoops made of light metal sheet were positioned between formers no.s 5 and 6. The motor and crankcase were supported by eight steel rods extending from a central point [aft of the motor] around the drive shaft.

The aircraft designers intended to provide the aircraft with exceptional vertical maneuverability, thus confounding the enemy and making make their "Torpedo" invulnerable to hostile fire. Evgeniy Kosyanenko worked out a mathematical model of possible firing angles in battle, and in these calculations it was seen that the novel control system would permit a sudden attack and departure from the enemy in the vertical plane. This method was seen to offer the chance for much success.

With respect to the actual KPI-5 aircraft, this was built in the Kiev Polytechnic workshops during 1916. Testing of the aircraft started in June 1917, the delay being explained by the need to assemble already a large number of airscrews for the RBVZ S-16 fighter of Igor Sikorskiy. The machine was transported to Siretskomoy airfield for flight tests. On 1 July 1917 the aircraft was broken when the pilot made a hard landing. The aircraft's tail struck the ground with sufficient force to break the tail skid, which in turn caused the airscrew to shatter on the ground, and also fracture the rear fuselage. The mishap was the result of Andrey Kasyanenko's over-control of the aircraft, this resulting from the unusually sensitive control system of pivoting biplane wings. The balance and center-of-gravity of the aircraft were also seen to be unsatisfactory. The pilot was unhurt in the incident. No further information is available.

Author's Note: Although the aircraft did not see any combat, and was not manufactured in series, it did demonstrate very original technical features, typical for designs in Russian aviation of that period. However, in hindsight we can see that not all innovative ideas were useful in practical application. But, we should not forget that the period was one of experimentation, and that mistakes were thus inevitable.

One should also note that the decision not to produce the aircraft was complex [not only related to the testing accident]. The later German design for a fighter by Pfalz was very similar to the KPI-5.