Training Fighter First flight: 1943 Lavochkin

The double training fighter La-5UTI was developed at the Lavochkin Design Bureau in the summer of 1943 based on the design of the La-5F aircraft. They took La-5F as the base, from which they removed oxygen, armor, one gun. The cockpit of the co-pilot (pilot-instructor) was equipped in place of the radio compartment of the single-seat Lavochkin. Moreover, they provided the opportunity not only to build new "sparks" using the existing serial equipment, but to remake combat fighters in them. La-5UTI had dual control, control from the first cockpit was automatically turned off if the instructor took control. The length of the fuselage of the La-5UTI did not change compared to the length of the fuselage of the La-5F, the two-seater was equipped with an ASh-82F engine.

Although the La-5UTI was intended for training flights, a sufficient number of elements of a combat aircraft remained on it - armored glass on the canopy of the cockpit, armored headrests for the pilots' seats (armored backs of the seats were not installed). At the same time, a number of "combat" systems had to be sacrificed in order to save weight: the La-5UTI did not have a pressurization system for fuel tanks with an inert gas, oxygen equipment, a radio station (on the La-5UTI of the first releases), equipment for dropping bombs. The volume of the central fuel tank had to be sacrificed - part of the space allotted for this tank on single-seat fighters was occupied by a second cabin; as a result, the total capacity of the La-5UTI fuel tanks became less than that of the La-5F. The armament of the training fighter consisted of one ShVAK cannon with 170 rounds of ammunition, but the hole in the engine hood and the breech fairing of the second cannon were left. Sight - standard for La-5, PBP-1B.

The reduction in the composition of the equipment made it possible to compensate for the increase in the weight of the airframe associated with the installation of the second cabin, the takeoff weight of the La-5UTI was 3210 kg - almost like that of the single-seat La-5F.

La-5F of the first releases had a cockpit canopy of the La-5 / LaGG-3 type, later cars received teardrop-shaped lights, characteristic of La-5FN. On the sliding parts of the lanterns of the first UTIs, there was no manual grip; on late production vehicles, the grip was equipped on the left side of the sliding segment.

The first flight of the La-5UTI took place on September 3, 1943, and the factory tests were combined with the State ones. On September 30, the Act on their completion was signed, and two days earlier, GKO Decree No. 4210 was issued on the conversion of part of the serial La-5 into UTI. But the NKAP for a long time could not decide who to entrust such work. Only on October 19, order No. 623 was issued, which determined the executor of plant No. 163 in Irkutsk, which was supposed to remake 20 La-5s by the end of the year.

The aircraft demonstrated a maximum speed near the ground - 552 km/h (5 km/h less than La-5F), at an altitude of 3500 m - 600 km/h. The aircraft climbed 5000 m in 5.7 minutes. In general, the flight characteristics of the training modification were close to those of the original single-seat fighter.

Although the State Testing Act stated that the stability and controllability of the La-5UTI was normal, and in terms of piloting technique it did not differ from a single-seat aircraft, the head of the LII Chesalov, by letter No. : "...neither the longitudinal nor the directional stability of the machine fit into the required range." May 5, 1944 "failed" the control tests of the La-5UTI, converted from serial No. 37210813 to the 30th field aircraft repair shops of the 1st Air Army. Only the installation of centering weights and a counterbalancer (a spring that created an additional load on the control stick) made it possible to ensure the safe operation of this aircraft, necessary for the Air Force. As for the effectiveness of the vertical tail, the La-5 was not ideally stable along the course either ... In general, the La-5UTI passed little, mainly the aircraft of all major modifications that came for repair were reworked, choosing the most worn ones.

The first La-5UTI retained the "generic features" of the La-5F - the ASh-82F engine, a single engine exhaust manifold, a wooden wing power set: the La-5UTI had three fuel tanks. Mastering the mass production of La-5FN was reflected in the design of La-5UTI. Double Lavochkins began to be equipped with ASh-82FN engines, the power set of the wing began to be made of metal. and instead of three tanks, install four. La-5UTI / ASh-82FN were equipped with RSI-4 radio stations, the radio station antenna was wire tension, the mast was not installed.

The release of La-5UTI continued after the phasing out of production of La-5FN. A large number of La-5UTIs were in regiments armed with La-7 fighters, since two-seat La-7UTIs appeared only in 1946 and few were built. La-5UTI remained the standard aircraft for training for flights on La-5 and La-7 fighters.

A number of La-5 combat fighters were converted into a double version by the repair shops of the Red Army Air Force. La-5F, La-5FN. During the conversion of combat aircraft into training aircraft, armor protection was completely dismantled.

In world aviation, scouts based on single-seat fighters were widely used, but the Red Army Air Force did not receive such machines from industry until the middle of the war, and everything that was was the fruit of the efforts of its own craftsmen. Among the scouts created in this way were La-5s, equipped with a planned or promising aerial camera AFA-IM, under which a hatch was cut in the fuselage, closed by a "plex".

On the Leningrad front, it was converted into a photo reconnaissance La-5UTI with tail number 100.

Photo	Description
	Lavochkin La-5UTI was reequipped into photographic reconnaissance aircraft at the Leningrad front
	Lavochkin La-5UTI with the ASh-82F engine.

In the spring of 1946. La-7UTI # 46210514 appeared at the Chkalovskaya airfield, which was radically different from its previous counterparts. The centering issue was resolved by moving the oil cooler under the second row of engine cylinders, removing the centering weights. The aircraft immediately became lighter by 111 kg.

The aircraft passed factory tests from June 16 to August 16, 1946, after which the aircraft was transferred to the Air Force Research Institute. The technique of piloting and the behavior of the aircraft on aerobatics remained the same as in the combat La-7. But some of the defects remained. So, the asynchronous release of automatic slats was noted (a long-standing illness that came from the La-5), with a sharp opening of which the control knob twitched. At the same time, La-7UTI was first tested for strength in flight, and he passed this exam.

It would seem that the road to a big life is open for a car, but this time it did not pass the state tests either. The reason for this was the insufficient strength of the elevator suspension assemblies, the unsatisfactory communication between the pilots on the SPU, the increased level of radio interference and the short range of both the communication radio station and the radio compass. In the act, according to the results of state tests, other shortcomings were also listed, but these were already trifles in comparison with the insufficient longitudinal stability and the increased temperature in the cabins characteristic of the first two-seater "La".

After the elimination of most of the defects, the spark began to enter the units and flight schools.

Photo	Description
	Drawing La-7 UTI
	Lavochkin La-7 UTI

Bibliography

• "The history of designs of planes in USSR 1938-1950" /Vadim Shavrov/
• "Planes of Stalin falcons" /Konstantin Kosminkov and Dmitriy Grinyuk/
• "Soviet aircraft of World War II" /V. E. Yudenok/
• "The Soviet planes" /Alexander Yakovlev/