Fw 190 A-5, 1.42 ata, 2700 rpm, Focke-Wulf Flugzeugbau, Abt: Flugmechanik L, 20.10.43
Performance and Handling Characteristics of the FW-190 Airplane AAF No. EB-104
P-47C, HQ VIII Fighter Command, 4 February 1943
P-47D-10 43-75035, 56" Hg., AAF Material Command, 11 October 1943
P-38G-1 42-12687, 44.7" Hg, AAF, Wright Field, February 10, 1943
P-51A-1 43-6007, AAF, Wright Field, April 2, 1943
Spitfire Mk IX (Merlin 63) +18 lbs/sq.in. Aircraft Data Sheet, 29.10.43
Spitfire Mk IX BS 543 (Merlin 66) +18 lbs/sq.in. A &AEE, 4 March 1943
Typhoon IB R.8762 +9 lb./sq.in., 3,700 RPM, A &AEE, 31 July 1943

Deliveries of the Fw 190 A-5 began in January 1943 when II./JG 2 received two aircraft. Production quickly picked up in the months following and deliveries of new production Fw 190 A-5’s to operational units peaked in April 1943. By the summer of 1943 JG 1, JG 2, JG 11, JG 26, JG 51, JG 54, JG 300, JG 301 and SKG 10 were, to varying degrees, equipped with the Fw 190 A-5. Some units were using small numbers of the type well into 1944. The Fw 190 production overview (Produktionsübersicht Fw 190) states that A-5 production was completed at the following factories at the times specified: Arado - March 43; Fieseler - May 43; Focke-Wulf - June 43; AGO - August 43. Altogether 723 Fw 190 A-5’s were built. 601 G-2 (A-5/U8) fighter bombers were also built.

The Fw 190 A-5 aircraft description sheet dated 1.11.44 (Flugzeug-Entwicklungs-Blatt FW 190) gives maximum level speed performance as 565 km/h (351 mph) at sea level and 655 km/h at 6.3 km (407 mph at 20,669 feet). However, the Fw 190 had the possibility of boosting speed at low levels by employing "C3 injection ". The additional fuel required was supplied from a t-fitting and regulated by the fuel pressure control box (see Abb. 2a: C3_Kraftstoffzusatz-Einspritzanlage). The fuel pump though was incapable of providing sufficient fuel for high gear operation with C-3 injection and it could not be used for climbing due to inadequate engine cooling. Use of C-3 injection in low blower gear was cleared sometime around the middle of 1943, principally for fighter bombers. The changes required were minor according to the Focke-Wulf modification instruction (Änderungsanweisung 104). By August 1943 the Reichsluftfahrtsministeriem (RLM) was satisfied with the reliability and performance gains of C-3 injection and ordered that an instruction be written for the Fw 190 A-4 Aircraft Handbook. The C3 injection could be used continuously for approximately 10-15 minutes. The pilot had to make certain that the temperatures did not rise over 85 degrees. Fuel consumption increased by approximately 70 litres per 5 minutes use of C3 injection.

While we have no concrete numbers today, it is known that many Fw 190 fighter bombers used this injection at low level while utilizing 1,65 ata engine boost. The Rechlin evaluation center tested a number of Fw 190s using C3 injection during the summer of 1943. The various aircraft tested demonstrated speed increases averaging from 30 to 45 km/h (19 to 28 mph). Normally it could be used up to a height of 1 km / 3,300 feet. For example, as reported in E´Stelle Rechlin Bericht Nr. 182929/43 dated 28.10.43, Rechlin obtained a speed of 570 km/h (355 mph) at sea level with Fw 190 No. 231 and could keep up this speed to 3,300 feet. The report also noted that increased emergency power was already being used operationally (Gegen die bereits erfolgte Zulassung der erhöhten Notleistung für den Notfall beim Fronteinsatz bestehen keine Bedenken). Focke-Wulf tested Fw 190 A-5/U8 No. 1428 with C3 and reached a speed of 578 km/h (360 mph) at sea level. This aircraft was equipped with a ETC 501 rack under the fuselage and two Messerschmitt locks without drop tanks.

Focke-Wulf recorded that BMW had cleared C3 injection for use with the high blower gear as of 20.1.1944. When a Fw 190 A had theses changes for C3 injection they could use it for both gears. So the performance chart of the Fw 190 looks very similar to the Fw 190 with higher boost pressure 1,58/1,65 ata (without C3 injection). Due to problems with the fuel pump and engine cooling, however, the boost pressure increase in high blower gear without C3 injection was only released in June 1944. It should be noted that while the Fw 190 A-8 entered service in April 1944, Focke-Wulf’s Technical description No. 284 for the Fw 190 A-8 dated 30.11.44 states Fw 190 A-8’s were equipped with increased emergency power utilizing 1.58/1.65 ata as of July 1944.

Following completion of Fw 190 A-5 serial production, brief trials were carried out from 30.8.43 – 1.9.43 of a Fw 190 A5 equipped with a BMW 801D engine operating at 1.58/1.65 ata erhöhte Notleistung. Charts prepared by BMW dated 26.11.43 presenting the results of these trials show maximum speeds obtained were 578 km/h (359 mph) at sea level and 680 km/h (423 mph) at 5.2 km (17,000 feet). However, the Fw 190 A-5/A-6 aircraft handbook issued in December 1943 notes the engine limitations for Start und Notleistung (3 minutes) as 1,42 ata with maximum speeds being 560 km/h (348 mph) at sea level and 660 km/h (410 mph) at 6300 meters (20,669 feet). It should be noted, however, that Part 7 of the handbook (Triebwerksbedien- und Versorgungsanlage) contains the possibility of the C3 injection with the higher boost pressure. By using the ÄAnw 104 the C3 injection could used for 10-15 minutes up to the height of 1 km with the A-5. It is also apparent from the Fw 190 A-5 Flugzeug-Entwicklungs-Blatt dated 1 November 1944 that 1.58/1.65 ata was not cleared for service use for this varient up to the date of this publication.

German climb figures for the Fw 190 A-5 as shown in the table and charts above are generally given assuming climb and combat power (Steig- und Kampfleistung) engine settings of 1.32 ata and 2400 RPM. The Steigflug section of the Fw 190 A-1 - A-8 Bedienvorschrift-Fl from February 1944, however, states that it was possible to climb with emergency power for 3 minutes with all Fw 190 A production series. Climb rate for the Fw 190 A-5 utilizing emergency power was approximately 1,5 - 2 m/s faster than the A-8 climb with emergency power, therefore, best climb rate at sea level would have been on the order of 3,662 - 3,760 ft/min (18.7 to 19.2 m/s) for the Fw 190 A-5.

Another procedure to upgrade the height performance of the Fw 190 was to use external air intakes for the BMW 801 engine. This is not to be confused with the Fw 190 trop version. The test report of FW 190 No. 528 dated 27.8.1942 shows that the critical altitude -Volldruckhöhe- increased from 6400 m to 7400 m when using emergency power. Therefore this Fw 190 reached a speed of 694 km/h/431 mph at critical altitude (full throttle height) (1,42 ata, 2700 U/min, 2 MG 151, G = 3640 kg, 25.8.42). Focke-Wulf documents indicate that the external air intake should be used for the Fw 190 series, however, for reasons not yet clear it saw little operational use. While no concrete numbers can be given for aircraft equipped with this modification, a small notification from 1944 notes that 250 construction kits were available for installation in Fw 190 fighters.

- Dietmar Hermann and Michael Williams, January 2009.

On the basis of data collected during tests of the experimental Fw 190A3/U1, Blaser's designer team became convinced that the planned additional armament would move the plane centre of gravity forward. The best solution to offset this was to move the engine forward. This was done with a 15 cm steel tube engine mount extension. This change (new engine mount) was introduced on the all production lines. It also led to an increase of the plane length to 9.10 m and gave life to the new Fw 190A-5 variant that from November 1942 replaced previous the A-4.

The A-5 also introduced small changes in the equipment (e.g. a new electrical artificial horizon and modernized oxygen respirator, and wide use of the FuG 25a IFF device). Radio equipment in the rear fuselage section was slightly moved back and the compartment cover was enlarged. Standard armament did not change and it remained 2x1 MG 17, 2x1 MG 151/20 E , 2x1 MG FF. Proper airframe design provisions meant that the Fw 190A-5 plane was prepared from the beginning to accommodate a large number of Umrustbausatz kits:

• Fw 190A-5/U1 - similar (with extended engine mount) to A-4/U1 airplane, temporary powered by a BMW 801 C-2 engine
   
• Fw 190A-5/U2 - long range fighter-bomber plane adapted to the night operation; it was fitted with anti-reflective strips over engine exhaust pipes on both sides. Mounted under the fuselage, an ETC 501 bomb rack for 250 or 500 kg bombs was added, additional fuel was placed in two external tanks of 300 l capacity each mounted under the wings on V.Mtt-Schloss (Verkleidetes Messerschmitt Schloss) shackles. In the wing leading edge an EK 16 camera and a doubled landing light were installed; the MG FF cannons were deleted in this modification. Based on this version, a night fighter with FuG 217 Neptun J-2 radar was built. However, number of planes built is unknown; the only known specimen of this variant had no bomb rack, camera or landing lights.
   
• Fw 190A-5/U3 - fighter-bomber with the ETC 501 bomb rack and without MG FF cannons. After a change of designation this was serially produced as Fw 190F-2. There was also a desert variant with dust filters designated as A-5/U3/tp (F-2tp).
   
• Fw 190A-5/U4 - reconnaissance fighter fitted with two Rb 12.5/7x9 mm cameras and reduced armament (2x1 MG 17 and 2x1 MG 151/20 E); produced also in a desert variant designated A-5/U4/tp.
   
• Fw 190A-5/U8 - long range fighter-bomber with two underwing mounted external fuel tanks (capacity 2x300 litres) and an under-fuselage mounted ETC 501 bomb rack; armament consisted of only two MG 151/20 E cannons. It was developed into Fw 190G-2 plane and later serially produced.
   
• Fw 190A-5/U9 - experimental plane with heavier armament, it was fitted with 2x1 MG 131 13 mm machine guns in place of MG 17 guns in the fuselage; in the wings the MG FF cannons were replaced by MG 151/20 E cannons. Only two were built (W.Nr. 150812, and 150816). The W.Nr 150816, BH+CF plane was later used as test bed for more powerful BMW 801 engine versions.
   
• Fw 190A-5/U10 - experimental plane (only two built W.Nr. 150861 and 150862). It was used as a test bed for a strengthened wing adapted to serial application of heavier armament, generally 20 and 30 mm cannons. Armament consisted of 2x1 MG 17 in the fuselage and 4x1 MG 151/20 E in the wings, later become a standard for A-6 version.
   
• Fw 190A-5/U11 - attack aircraft with two 30 mm Rheinmetall-Borsig MK 103 cannons mounted in underwing pods; only one plane existed (W.Nr. 151303, RG+ZA). This kind of armament became later standard as Rustsatz 3 (R3) kit.
   
• Fw 190A-5/U12 - proposal for heavier armament consisting of six MG 151/20 E cannons. They were mounted under the wing in two additional WB 151/20 pods with two cannons in each pod; complete armament could be 2x1 MG 17, 2x1 MG 151/20 E and 2x2 MG 151/20 E. It was also a model for Rustsatz 1 (R1) kit for Fw 190A; two planes (BH+CC, W.Nr. 150813 and BH+CD, W.Nr. 150814) with such armament were completed.
   
• Fw 190A-5/U13 - three prototypes (V42, W.Nr. 151083, GC+LA; V43, W.Nr 150817, BH+CG and V44, W.Nr. 150855) built, long range fighterbomber with two underwing V.Fw Trg. (Verkleideter Focke-Wulf Trager) bomb racks, adapted for carriage of 300 litre capacity fuel tank or 250 kg bomb. The plane was equipped with an automated pilot device and application of knifes for barrage balloons lines cutting on the wing leading edge was considered; one plane was experimentally equipped with a lacunar exhaust flame damper (GC+LA?). Armament consisted of two MG 151/20 E mounted in the wing roots. Plane was later produced under designation Fw 190G-3.
   
• Fw 190A-5/U14 - torpedo plane adopted for transportation of one aerial torpedo LT F 5b mounted on the under-fuselage ETC 502 rack; plane had an enlarged fin (similar to Ta 152) and heightened tail wheel strut to eliminate the possibility ground contact by the torpedo; armament consisted of only 2x1 MG 151/20 E cannons. Two planes were tested TD+SI, W.Nr. 150871 and TD+SJ, W.Nr. 150872.
   
• Fw 190A-5/U15 - experimental plane adopted for transportation of the unpowered Blohm und Voss 246 Hagelkorn (LT 950) flying bomb for destroying of naval targets, radio controlled by an Askania company produced ALSK 121 device. Extensively tested during second half of the 1943, later in the test program an A-8/F-8 series plane (W.Nr 130975) was also included, but tests were cancelled shortly after it was found that because of poor construction, the BV 246 had frequent defects.
   
• Fw 190A-5/U16 - prototype of a fighter plane with heavier armament (W.Nr. 130975), for destruction of bomber formations. The MG FF cannons were replaced by heavier 30 mm cannons Rheinmetall-Borsig MK 108. This armament was later standardized as the Rustsatz 2 (R2) kit.
   
• Fw 190A-5/U17 - fighter-bomber with under-fuselage mounted ETC 501 bomb rack and four underwing mounted ETC 50 bomb racks (2x2 50kg bombs). With A-5/U3, this variant was a model for the Fw 190F attack aircraft; basic version for the later Fw 190F-3/R1 variant. Armament was standard without MG FF cannons. Also used in a desert modification.

Finally, in response to the intensifying of the Allies' bombing, numerous Fw 190A-5/R6 planes belonged to units operated in Reich defence system (Reichsverteidigung) have been found.

As an interesting detail, we must mention the existence of a Fw 190A-5 plane with external turbosupercharger inlets. The engine cowling with these inlets was proposed as an alternative, but was not used widely because of higher induced aerodynamic drag.

There exists also a photograph of an A-5 fighter from a II./JG 54 unit deployed to the Eastern Front temporary adopted to bomber missions by four (2x2) under-fuselage mounted ETC 50 bomb racks.

In the autumn 1943, one A-5 plane (W.Nr. 157347) were used as the V45 prototype for tests of the GM 1 system that by injection of pressurized nitrogen monoxide as an oxidant to increase engine efficiency at high altitudes. This device was later standardized as the Rustsatz 4 (R4) kit.

In connection with the planned 1765 kW (2400 KM) BMW 801 F engine production to be used for A-9 and A-10 series planes, in December 1943 Focke-Wulf was ordered to prepare an A-5 airframe (W.Nr. 410230) as the V34 prototype for tests with the experimental BMW 801 V 85 engine; however, we have no evidence that the engine was supplied and mounted on that particular Fw 190 plane. Serial production of BMW 801 F engines never started and A-9 series planes had TS/TU engines mounted.