Aviation of World War II
Comparison of La-7 and FW-190
The La-7 fighter became the highest achievement of the Soviet wartime design school. Aircraft designers were able to achieve the best possible results in the most difficult conditions by simple means and the most primitive construction materials. The aircraft were manufactured by factories, the technological level, as well as the qualifications of the workers, which could not be compared with Western factories. Given the specific conditions in which the La-7 was created, and the conditions in which the fighters were built, we can only admire the designers who managed to make this outstanding aircraft and take off their hats in front of them.
It is believed that the first Soviet fighter that surpassed German aircraft in its flight characteristics was the La-5FN. This is not entirely true. The conclusion about the superiority of the La-5FN over, for example, the Bf 109G, is made on the basis of the test results of the La-5FN standard and the captured Messerschmitt. Comparison of a reference fighter and an aircraft that managed to fight and partially exhausted its resource is incorrect. So, the same La-5FN captured as a trophy during trials in Rechlin showed a maximum speed of 50 km / h less than its prototype on trials at the LII*.
One of the significant drawbacks of the La-7 aircraft should be considered the absence of an automatic control unit for the operation of the propeller-engine group on the aircraft. It is not necessary to explain what a rapid change in the engine operating mode means in battle. The fact that on the FW-190 was controlled by the movement of one lever, on the La-7 required the manipulation of eight controls. It was possible to simplify the control of the propeller-motor group only by installing an 82-FN-VG regulator and an automatic thermostat ARTG-43 on the e-67 supercharger. The fighters began to receive this equipment only from the La-7, serial number 38101356, which passed flight tests from March 20 to April 8, 1945.
One of the most important factors that can influence the comparison results is the operating mode of the powerplant. The main flight characteristics of aircraft, such as speed, rate of climb and maneuverability, largely depend on it. The mode of operation of the engine was especially important for fighters. Piston aircraft engines during the Second World War in England and the United States, as a rule, had several operating modes: afterburner (including emergency, combat and takeoff modes), nominal, maximum, cruising, and others. The nomenclature of operating modes of German engines was usually somewhat different: takeoff afterburner (the permitted operating time was 1-3 minutes), sometimes there was a special mode for climb (usually 3 or 5 minutes), continuous operation mode (30 minutes), etc. The operating time of motors at high power modes was strictly regulated. So, for the most intense emergency regime, the time limit was usually from 1 to 5 minutes. The pilot could use this mode only in the most extreme, extreme cases. The operating time of motors in combat mode was usually limited to 5-15 minutes (usually 10-15 minutes). The combat mode acquired exceptional importance for fighters as the main mode of the engine's combat use, which determined the result of air combat. Unfortunately, the published data of British and American cars, the engines of which had the specified nomenclature of modes, often correspond not to combat, but to emergency, or, as they were also called, maximum modes. In the absence of direct documents, approximate data for combat modes can be obtained only by recalculation, for which the high-altitude characteristics of the motor are required. It can also be noted here that the Soviet serial engines did not have high-altitude afterburners, and all the flight characteristics of our aircraft correspond to the nominal operating mode. Only the M-82 and M-82FN (ASh-82FN) engines had a 10-minute takeoff afterburner, which increased the speed and climb rate of fighters at low altitudes.
The engines of the German FW 190A.D and Bf 109G fighters were sometimes equipped with a water-alcohol mixture (MW-50) injection system. thanks to which it was possible for a while to noticeably increase the boost and revolutions in excess of the standard values, and with them the engine power. It turned out to be a kind of combat or, as a rule, an emergency regime. Of course, this improved the basic flight characteristics of the aircraft, but at the same time the power plant became more complex and the weight increased. Such systems were not installed on all aircraft.
Summarizing everything that has been said above about the principles of comparing aircraft flight characteristics, we can summarize the following brief results.
Firstly, it is advisable to carry out the comparison for aircraft at the same stage of development, that is, the data of the experimental (or reference) specimens should be compared with the experimental ones, and the serial ones - with the serial ones (based on control tests).
Secondly, the flight characteristics of captured aircraft can be taken as a basis for comparative assessments only if you are confident in the normal operation of the materiel and the acceptable state of technology.
Thirdly, the comparison of the flight characteristics of military vehicles should be carried out for such operating modes of motors, which were widely used in the course of combat work. These are either combat or nominal modes.
Fulfillment of all these conditions will make it possible to draw comparative conclusions about the real ratio of flight data of the compared aircraft.
* LII - Letno-Issledovatel'skii Institut - Ministry of Aviation Industry Flight Research Institute
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* Using a 10 minute afterburner.
Fw 190A-4, presumably from JG 51. Non-standard camouflage with broken fields of dark green and green paint, typical of 51st and 54th squadrons on the Eastern Front, is visible. The cock and stripe on the fuselage are yellow.