Aviation of Word War II

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La-11


The La-11 ser.5120768 under evaluation
  • Long-Range Fighter
  • Lavochkin

It took OKB-301 only six months to create the 134 (La-9M) aircraft, the future La-11.

In May 1947, test pilot A.G. Kochetkov, for the first time lifted the car into the air. In 18 flights with a total duration of 12 hours 37 minutes, the maximum horizontal speeds and rate of climb at the nominal operating mode of the engine, the technical range and duration of the flight were determined. On June 19, the first aircraft entered state tests at the Air Force Research Institute. Compared to the La-9, the 134 was fitted with three NS-23 cannons, reducing the ammunition load of the remaining guns to 225 rounds. The oil cooler was moved to the lower part of the engine hood and the capacity of the oil system was increased. Five days later, at the Chkalovskaya airfield, its substitute "134D", with a greater range, appeared. The fuel reserve on it was increased from 825 liters to 1100 liters, additional gas tanks were installed and the suspension of two non-resettable tanks with a total capacity of 332 liters was provided.

The increase in the take-off weight of the aircraft required the strengthening of the landing gear and the installation of main wheels with a diameter of 660x120 mm with high-pressure tires. The tail wheel damper was mounted on a link suspension.

The aircraft was equipped with aeronautical lights, an AFA-IM aerial camera for scheduled photography, and an automatic temperature control for the engine cylinder heads.

The increased duration of the flight accompanied by bombers (over seven hours) required the installation of an additional oxygen cylinder.

Normal flight weight has increased by 571 kg. Despite all the efforts of aerodynamics, with a constant power of the power plant, it was not possible to meet the requirements set by the resolution of the Council of Ministers. The only exceptions were the range and the practical ceiling. Suffice it to say that the maximum speed at the ground was 25 km / h, and at an altitude of 6200 m - 6 km / h less than required.

During the test period, which ended on July 24, both aircraft made 71 flights with a total duration of 59 hours and 13 minutes.

According to the test results, it was noted: In terms of the technique of performing aerobatics, as well as behavior on aerobatics when fully refueled, the aircraft differs significantly from the serial La-9. ... the speed of the bend is 20-40 km / h higher according to the device; in addition, on a bend, the aircraft tends to increase the roll and angular velocity. The turn time is also increased. When performing a combat turn, the aircraft quickly deadens the speed and tends to increase the roll.

Piloting a fighter with full fuel is much more difficult than a La-9. As the fuel depletes, piloting becomes easier and with a fuel remaining of 400-600 liters, the technique for performing aerobatics, as well as the behavior of the aircraft on aerobatics, is similar to those for the serial La-9.

The loads on the control stick from the elevators and ailerons are less than on the La-9 aircraft, but are within normal limits.

At full refueling at flight speeds of 300-450 km / h, the aircraft has an insufficient longitudinal stability margin. The flight stability of the aircraft is sufficient.

The aircraft was given the name La-11 and at the plant number 21 its serial production began under the designation "product 51", continuing until 1951. In 1947. the plant produced 100 cars, and in 1948 the largest number was 650. In the same year, production was stopped, but the next year it produced 150 more cars. In 1950, 150 were delivered and in 1951, 182 aircraft. A total of 1182 vehicles were built.

Like its predecessor, the escort fighter was constantly being improved. Only in 1948, 210 changes were made to its design, which contributed to the improvement of operational characteristics. The La-11 was supplied not only to combat units, but also to flight schools of the Air Force and Navy aviation.

In July 1950, factory tests were completed, and on September 22 - state tests of La-11 in the version of a photo reconnaissance aircraft. A swinging installation with an AFA-BA-40 camera was installed on the machine. In the same year, by order of the Air Force, 100 fighters were converted into reconnaissance aircraft. In the version of the reconnaissance aircraft with outboard tanks, the La-11 turned out to be overweight, lacking engine power. In 1951, they tried to raise the takeoff power of the ASh-82FN to 2000 hp. But, as it turned out, to ensure reliable operation of the engine, it was necessary to make significant changes to its design and further work was stopped. Although later, for the IL-14 passenger aircraft, they created a modification of the ASh-82T with a take-off power of 1900 hp, but this was the limit. On one machine, which was tested at the Air Force Research Institute of the Air Force, an automatic for switching the supercharger speeds was installed.

In 1950, 150 La-11s were retrofitted with RV-2 radio altimeters, MRP-48 marker radio receivers and ARK-5 automatic radio compasses. Apparently, not all production vehicles leaving the factory airfield were fully equipped with radio equipment.



WW 2 Soviet Fighters
La-7 La-9 La-11
Crew One One One
Year of issue 1944 1946 1947
Dimensions
Length 8.60 m 8.63 m 8.62 m
Wing span 9.80 m 9.80 m 9.80 m
Wing area 17.5 m² 17.6 m² 17.6 m²
Height 2.540 m 3.56 m 3.47 m
Weight
Empty weight 2,638 kg 2,638 kg 2,770 kg
Loaded weight 3,265 kg 3,425 kg 3,730 kg
Max takeoff weight 3,400 kg 3,676 kg 3,996 kg
Powerplant
Engine ASh-82FN ASh-82FN ASh-82FN
Power 1,850 hp 1,850 hp 1,850 hp
Performance
Max speed at sea level 579/613* 640 562
at altitude 661 km/h 690 km/h 674 km/h
m 6000 m 6250 m 6200 m
Time to 5,000 m 5.25/4.6* 4.7 6.6
Time of turn, sec 19 20-21 24-25
Rate of climb 18.3 m/s 17.7 m/s 758 m/min
Wing loading 3187 kg/m² 195 kg/m² 212 kg/m²
Power/mass 0.42 kW/kg 0.40 kW/kg 0.37 kW/kg
Service ceiling 10,450 m 10,800 m 10,250 m
Range 570 km 1,735 km 2,235 km
Armament
Cannon 2×ShVAK
or 3xBB-20
4×NS-23,
75 rounds/gun
3×NS-23
75 rounds/gun

* Forcing of the engine during 10 minutes.

Photo Description
Drawing La-11

Drawing La-11

The Aircraft '134' under evaluation. Chkalovskaya airfield, summer 1947

The Aircraft "134" under evaluation. Chkalovskaya airfield, summer 1947.

Photo Description

La-11 with non-resettable fuel tanks on the wing tips

La-11 464-th separate Red Banner reconnaissance air Regiment

La-11 in the exhibition of Chinese Aviation Museum. Photo by Jurgenson

Bibliography

  • "The history of designs of planes in USSR 1938-1950" /Vadim Shavrov/
  • "La-9, La-11 Fighters" /M-Hobby #11/

13 06 2015
Film Well, finally. The process has begun. One plane still got an automatic supercharger gearshift :-)

13 06 2015

The closest analogue of La-11 is the American P-47 Thunderbolt fighter of the Republican company with an air-cooled engine. One of its variants (P-47D-10 RE) in April-May 1944 was tested at the Air Force Research Institute and LII.

Comparison of La-11 and P-47D-10-RE the load on engine power, the domestic fighter was almost two times lighter than the "American", which testifies to its more successful selection of propeller, better aerodynamics, and with a wing of comparable aspect ratio and worse takeoff and landing characteristics. The length of the takeoff run of the P-47, depending on the takeoff weight, varied from 960 to 2000 meters, which required large airfields. The turbochargers, which provided the Thunderbolt engine with a high altitude, also had their say.

Due to the excessive takeoff weight, the "American" was extremely inert. It climbed more slowly when the engine was in combat mode, but in emergency mode the P-47 was faster. The time for a single turn was commensurate with the La-11. However, the P-47 was not intended for mobile combat.

A few months before the start of flight tests of the prototype La-11, the Air Force Research Institute received an American twin-engine fighter P-38L-1 Lightning. Flight tests, completed in April 1947, showed that, despite the heavy weight, almost twice the weight of the La-11, the American's range with outboard tanks turned out to be shorter. The rest of the characteristics were also worse, with the exception of the bend radius and practical ceiling.

13 06 2015

It should be noted that La-11 fought in China and Korea, shooting down American planes. However, the La-11 was never shot down by any B-29. "Superfortresses" usually flew for bombing at an altitude of 10,000 m. To gain this altitude, the La-11 took 26 minutes, while, at such an altitude, the speed advantage of the La-11 turned out to be only 20 km / h. American bombers with a gentle dive easily evaded pursuit.

13 06 2015


Comparison of P-51D with La-11 shows that with approximately the same specific wing loading and higher thrust-to-weight ratio, a lighter aircraft 11 had a slightly shorter range and top speed. This can be explained by the large frontal resistance of the ASh-82FN radial motor. La-11 also had a worse ceiling, which is apparently due to the lower altitude of the engine.

"Mustangs" of modification "D" in small quantities came to the Soviet Union during the Great Patriotic War, and some of them were flown by test pilots of the LII. It was not possible to fully determine the flight characteristics of the machines, but they did draw some conclusions. The heavier P-51D climbed more slowly and was less maneuverable up to 5,000 meters. Above, the car seemed to be replaced. In general, it was a good escort fighter, especially when you consider that long-range bombers flew at high altitudes. And in this respect, it was somewhat superior to the La-11.