Aviation of World War II
At the beginning of 1942, the company concluded that the characteristics required by the task could not be achieved with the BMW-801 engine. As a result, they decided to switch to a liquid-cooled engine. The tank preferred the DB-603, but it was not popular with the Air Ministry and was created on its own initiative. The tank was informed that the improvement in fighter performance was to be achieved either on the basis of the VMW-801 or using the newly launched Jumo-213. Making a concession, the Technical Department agreed to the creation of the Fw.190 variant with the DB-603, but it was obvious that this variant would only be a backup to the main one. In addition, the DB-603 engine was not planned to be mass-produced.
Among the large number of Focke-Wulf proposals, the Technical Department chose three: the Fw.190b high-altitude fighter with a pressurized cockpit, a BMW-801 engine, with a wing area increased by 11%; Fw.190c high-altitude fighter with DB-603 engine; mid-altitude Fw.190d, similar to the A-series aircraft, but with a Jumo-213А engine. The last proposal aroused the greatest interest, since the installation of a new engine on an existing airframe promised the fastest solution to the problem of improving the flight performance of a fighter, and even without serious delays in the assembly lines. For these works, several Fw.190a-0 airframes and 10 of 15 specially ordered vehicles for testing were used.
The first experimental aircraft of the B series, the Fw.190-V13, was already undergoing flight tests, but since BMW did not have time to supply the turbocharger, the BMW-801C-1, together with the GM-1, was replaced by the DB-603A-0 with a frontal radiator. As a result, the V13 was actually the first aircraft of the C series, although without a turbocharger and pressurized cabin. The installation of a liquid-cooled engine increased the overall length of the aircraft by 0.66 m, but the airframe remained practically unchanged. The alignment of the aircraft was maintained by moving the equipment. The Daimler-Benz engine was 140 kg lighter than the BMW-801. The second experimental aircraft of the B series - Fw.190-V16 (CF + OW) was also without a pressurized cabin and a turbocharger. They were supposed to be installed in the future. They were followed by the first aircraft of the C series - Fw.190-V18 (CF + OY) - again without a pressurized cabin and a turbocharger. The high-altitude tests started in Bremen with the V13 in April 1942 were continued in Langenhagen with the V16 and V18.
Initially, all three experimental aircraft were equipped with DB-603А engines - 12-cylinder inverted V, takeoff power 1750hp, 1850hp at an altitude of 2100 m and 1625hp at an altitude of 5700 m. The experimental Fw.190-V16 was transferred on August 2, 1942 " Daimler-Benz" for testing the engine and supercharger. Prior to the transfer to Echterdingen on this aircraft, the oil cooler was moved under the hood of the frontal radiator. Immediately upon arrival, the DB-60ZA was replaced by a DB-603E with a more powerful supercharger. The aircraft was tested with MW-50 and GM-1 forcing systems. Using the MW-50 raised engine power from 1800 to 2250 hp at the ground and from 1630 to 1900 hp at 5500 m. and with an injection of 7 kg / min in the "emergency mode" the power increased to 1490 hp at an altitude of 9900 m.
At the very beginning of the tests in Echteridingen, the Fw.190-V16 under the control of the flag captain Ellenrieder reached a speed of 720 km / h at an altitude of 7000 m, and when using the MW-50, the rate of climb near the ground reached 22 m / s. On October 10, Ellenrieder reached an altitude of 12,000 m. Soon, flying at such an altitude became commonplace - the aircraft sometimes stayed on its ceiling for 1.5 hours. Such a flight was accompanied by a heavy load on the pilot. Nevertheless, the Technical Department demanded that the ceiling be raised to 14,000 m, but it was clear that this required a turbocharger and pressurized cabin.
The German Aeronautical Armaments Experimental Institute (DFL) and Hirt Motoren created turbochargers for use on high-altitude aircraft, although "childhood illnesses" held back their use. The TC-11 compressor designed by DFL, designed for altitudes of about 12,000 m, was ready for installation on an aircraft from the end of 1942. It was it that was used on the prototype of the C series, renamed Fw.190-V18 / U1. TC-11 was mounted at the bottom of the fuselage. The DB-603G engine received a faster supercharger and a higher compression ratio. The exhaust manifold ran back over the wing to the compressor turbine, and the compressed air was pre-cooled and then fed into the turbocharger.
The motor drove a four-bladed propeller and developed 1900 hp on takeoff and 1560 hp at an altitude of 7400 m. With the TC-11, 1600 hp power was maintained up to an altitude of 10600 m. and pressurized cabin. It was previously tested on four Fw.190b - V24, V26, V28, and V29. The cabin was formed by a sealed floor, a front fire wall, side panels and a reinforced heated lantern of the "sandwich" type. These aircraft, known as the Fw.190b-0, were powered by the BMW-801D engine from the GM-1 and differed little from each other. The exception was V24 with a slightly increased wingspan - up to 10.85 m long and up to 19.7 sq.m. This wing was originally intended for aircraft of the B and C series. It was tested on the Fw.190-V15, converted from the pre-production Fw.190a-0 and later equipped with the DB-603 engine.
Pressurized cabin tests were constantly frustrated due to problems with valves and the need to frequently change the rubber gaskets that seal the panel joints. In addition, some necessary components from Langenhagen did not arrive. In May 1943, the Fw.190-V24 was briefly tested at Rechlin. Preliminary tests were carried out two months earlier on the V18 / U1, but without the pressurized cabin and turbocharger.
Five airframes - V29-V33 - were completed as experimental machines of the C series. All of them had DB-603G engines with a four-blade Schwartz wooden propeller and a turbocharger under the fuselage, which is why they were nicknamed "kangaroos". V29 and V30 were transferred to "Hirth Motoren" in the summer of 1943 for the installation of Type-9-2281 turbochargers, and V31-V33 received the DFL TC-11 created by DFL. All of them were equipped with a pressurized cabin.
The Fw.190-V16, which remained in Echteredingin as a flying testbed, instead of the DB-603E received the DB-603AA with a more efficient supercharger with a fluid speed shift clutch from the DB-603E. With the new propulsion system, the aircraft reached a speed of 715 km/h at an altitude of 9000 m and 646 km/h at 12000 m with a flight weight of 3700 kg. In the meantime, it became clear that the Fw.190b would not go into series due to low flight data, and the remaining aircraft were used to test pressurized cabins. The C-series aircraft were delayed in testing turbochargers. The Fw.190-V31 was written off after an emergency landing on May 23, 1943. Malfunctions constantly plagued the DFL and Hirt Motoren turbochargers. The main problem was the exhaust pipes, which could not withstand the high temperature of the exhaust gases. By the autumn of 1943, it became clear that a lot of time would be required for fine-tuning. Accordingly, the attitude of the RLM to the Fw.190c changed, but work on turbochargers continued.
The designation Ta.153 was assigned by the RLM to the Focke-Wulf project for the second stage of the 1942 program.
There was no experimental aircraft - the Technical Department provided for the conversion of the Fw.190c-V32 to test individual Ta.153 solutions. The TK-11 turbocharger was removed, the cabin pressurization was excluded. The lantern became teardrop-shaped. The rear fuselage was lengthened and the fin enlarged. The engine remained DB-603G with a ventral oil cooler. The propeller is four-bladed, the landing gear is electric, the chassis base has been increased.
Work on Ta.153 was stopped due to the impossibility of breaking up the established production at a critical moment of the war. But certain Ta.153 solutions after successful tests of the Fw.190-V32 were used on the Ta.152. V32 was again redesigned for the Jumo-213 engine and the wing from the Ta.152h-V25. Testing was resumed under the designation Fw.190-V32/U1.