Summary
Lutz Naudet placed these performance trials in context:
Now lets come to the interpretation as to why both Wk.-Nr. 001 & 002 generally fall short of calculated values. The first problem with all flight trials of Wk.-Nr. 001 & 002 is that they were done with the initial batch of production engines, which have well documented problems with supercharger performance. Those first production engines produced 60-100PS less than the book values used for performance calculations. The second problem is the engine gap. The drag data for the D9 most likely comes from scale models; those models will not have the engine gap as they are "carved out of one piece of wood". The scale model, therefore, has a smoother surface than the real airplane. The speed increase in the tests, where the gap was sealed, support this assumption. Nevertheless, the tests are representative of performance for operational Fw 190 D9s. As best as can be determined, the engine gap seal was never introduced into serial production due to rubber shortages. It should be noted however, that operational planes with a good surface finish and an engine running to book values will perform better than both Wk.-Nr. 001 & 002. This is supported by the few speed runs with the JUMO 213A tested on the bench.
Now lets examine the “Erhöhte Notleistung” and “MW50” speed runs. When looking at the results, we must keep in mind that Wk.-Nr. 002 was specially rigged for those runs to enable the testing of both settings in one airplane. Wk.-Nr. 002 engine installation was therefore not in a standard production condition when carrying out those speed runs. Standard production planes had either “Erhöhte Notleistung” or “MW-50” available, not both. The surface finish and other equipment of Wk.-Nr. 002 during this test is the equivalent of a standard production plane. Report #2 focuses on the speed increase through “Erhöhte Notleistung” and “MW-50” compared to Take-Off/Emergency rating. Report #3 examines in detail the speed increase from sealing the engine gap, but the tests were only carried out up to 3,6km. The bottom line for those reports is that they provide us with a good overview of how the “Erhöhte Notleistung” or “MW50” boosted performance, but only up to ~3,6km. The speeds attained, without engine sealing, between SL and 3,6km can be considered representative for operational aircraft.
The following chart depicts level speed performance as calculated by Focke-Wulf along with the results presented in Report 3 of Wk Nr. 210002.
For metric verison of above the chart see Here
The condition representative of standard production Fw 190 D-9’s during 1945 is as follows: Jumo 213A operating at 1.8 ata with B4 fuel & MW 50, equipped with ETC 504, main wheel fairing doors absent/fixed and engine gap not sealed. Of all the data charted in the compilation curve linked above, that curve best fitting the condition of a standard production Fw 190 D-9 is curve 4 of the Focke-Wulf Fw 190 D-9 chart dated 11.3.45 (the red line). One shortcoming of this curve, when viewed in context with other curves from Focke Wulf’s Flugmechanik Department, is that it assumes the installation of the engine gap seal and is therefore approximately 13 km/h optimistic relative to the condition of delivered production aircraft (with rack minus the drop tank).
Dietmar Hermann summarized FW 190 D-9 performance as follows:
I haven’t read or heard that the D-9 was tested with the Jumo 213 and C3 fuel. I know that at the beginning of development Focke-Wulf made a distinction between the normal Jumo 213 and the Jumo 213 with 100 octane fuel. I think that there was not a problem with the engine; rather there was a problem of the fuel’s availability. In my book I have published one chart from 3.1.45 (page 154) showing FW 190 D-9 performance with B4 fuel with MW 50 injection operating at 2,02 ata (Sondernotleistung ). However, I have no evidence showing that 2,02 ata was enabled by the end of the war. I think that the D-9 was flown either with the 1900 PS update or with MW50 injection (2100 PS).The development announcement of the D-9 said that all D-9 were delivered with the ETC 504 and the 170 l or 300 l drop tank (Entwicklungsmitteilung Fw 190 D-9, Blatt XV b2 and b3 from 31 May 44 and renewed at 20 June 44). The first test report of FW 190 D-9 serial number 210002 states that the D-9 lost 8..10 km/h. with the ETC 504 and the fixed wheel flaps (delivery condition).
From Fw 190 “ Long Nose” , pg 103: “Focke-Wulf conducted experiments with a Fw 190 D-9 (WNr. 210 002, TR+SB) in an attempt to further increase the performance of production aircraft. Gaps in the engine cowling fore and aft were sealed with rubber. In the course of these experiments an increase in speed of 17 km/h was achieved at combat power. Focke-Wulf subsequently advised the manufacturing plants to pay special attention to proper sealing of the engine compartment pending approval by E-Stelle Rechlin. Rechlin rejected the idea of rubber seals for the engine compartment, however.”
D-9 production aircraft did not have the slit sealing (engine gap seal). I have the information from a document named "Lfd. Entwicklungsarbeiten Fw 190/Ta152" from 8.1.45 updated 20.3.45 with the handwritten statement "24.3. Rechlin lehnt ab!". So I think that this was the expected answer about the previous troubles during the Focke-Wulf testing. (Test report No. 3 of Fw 190 D-9 210002 dated 24.10.44 shows a 13 km/h difference at SL operating at 1.8 ata between aircraft with sealed and unsealed engine gaps (595-608) - Ed.).
Flight Report Nr. 4 of Fw 190 D-9/210002 presented the following results: Operating at 1,75 ata, a maximum speed of 606 km/h (376 mph) at ground level was obtained. The maximum speed in the first gear was 650 km/h (404 mph) at 2,7 km (8858 ft.). The condition of the aircraft was as follows: D-9 production condition with methanol installation, surface smoothed/primed and polished, seams & cracks sealed, operable wheel flaps, gap at engine sealed (D-9 Serienzustand mit Methanolanlage, Oberfläche gespachtelt und poliert, Spalte abgedichtet, bewegliche Radklappen, Spalte am Triebwerk abgedichtet.) These values did not quite reach the characteristic curve from the comparison dated 15.12.44.
So we can state: D-9 without engine sealing - 15 km/h; with ETC 504 + fixed wheel covering about -10 km/h. This indicates that the D-9 reached the following speeds - minimum:
- 606 km/h (377 mph) at sea level with MW 50 injection and engine sealing; without ETC 504 and variable wheel covering.
- 591 km/h (367 mph) at sea level with MW 50 injection; without engine sealing, ETC 504 and variable wheel covering.
- 581 km/h (361 mph) at sea level with MW 50 injection, ETC 504 and fixed wheel covering; without engine sealing.
With 1900 PS engine set up:
- 578 km/h (359 mph) at sea level without engine sealing and variable wheel covering.
- 568 km/h (353 mph) at sea level with ETC 504 and fixed wheel covering.
Hermann wrote of testing the Fw 190 D-9 in his book Focke-Wulf Fw 190 "Long Nose" ISBN: 9780764318764:
In the beginning only the Fw 190 V17/U1 and Fw 190 V53 prototypes were available for extensive flight testing. The V53 was used for performance trials at Lanenhagen. For the most part these confirmed the estimated performance figures. The V53's armament initially consisted of two MG 131 machine-guns in the fuselage, two MG 151 cannon in the wing roots and two MG 151s in the outer wings. This was the armament originally planned for the production D-9s. The outer wing cannon were later removed. The V53 was painted in a standard camouflage finish. At a gross weight of 4070 kg with ETC 503 external stored rack, the V53 achieved 555 km/h at ground level at 3,250 rpm (emergency power). During flight trials the V53 was involved in a heavy forced landing. It was subsequently repaired, but for safety reasons it was limited to low-level flights.When production began, aircraft from the production line joined the test program. The first and second aircraft from the Sorau production line were flown to Langenhagen to participate in series testing. Werknummer 210 001, manufacture's code TR+SA, made its first flight on 31 August with chief test pilot Hans Sander at the controls. On 7 September 1944, just a few days after the D-9 arrived at Langenhagen, the first case of engine trouble was encountered after just four hours flying time. This aircraft underwent four engine changes by 9 January 1945. Even the Jumo 213 A had teething troubles. The second aircraft, Werknummer 210 002, TR+SB, followed on 15 September 1944. The aircraft was piloted by Hauptmann Schmitz on its initial flight. These two production aircraft were used by Focke-Wulf at Langenhagen for long term testing until March 1945. While 210 001 was to have been made ready for delivery to the Luftwaffe in March 1945, 210 002 was scheduled to take part in further performance trials.
The fourth production machine, Werknummer 210 004, TR+SD, was assigned to the E-Steel Rechlin, but crashed there on 25 September 1944. The exact cause of the crash remains a mystery. Another Fw 190 D-9, Werknummer 210 007, TR+SG, which had been used for static and air gunnery trials at Tarnewitz, was assigned to Rechlin as a replacement. On its arrival at Rechlin, however, 210 007 made a crash landing (10% damage) and subsequently had to be repaired. Rechlin was subsequently assigned the sixth production aircraft for further testing.
The ninth production aircraft, Werknummer 210 009, TR+SI, was flown from Sorau to Langenhagen on 18 September 1944. After just a few test flights, on 26 September this D-9 was transferred to Jumo in Dessau to serve as an engne test-bed. Flight tests were still being carried out there in March 1945, including some with four-blade VS 19 propeller that was to be used on the Ta 152 H.
It was originally intented that two aircraft should be converted to test the Fw 190 D-9 with the MW 50 system. The company planned to convert Werknummer 210 002 at Langenhagen and Werknummer 210 048 was equipped with the system in Sorau. The machine was supposed to go to Rechlin for testing of the MW 50 system, however, it crashed at Sorau while on the third flight. Pilot Finke was killed. In spite of this, testing of the MW 50 system continued on the ground. Interestingly, the special tank was filled with water only, as no methanol was available. Estimated maximum speed at ground level without methanol-water was 540 km/h at 3,300 rpm and 1.5 atm of boost. With methanol-water, maximum speed at ground level was 585 km/h at 3,300 rpm and 1.76 atm boost. In production aircraft it was planned that the MW 50 system could be used to draw fuel or methanol/water from the 115-liter tank. On account of delivery difficulties, however, it was decided to use the tank with methanol-water only, and this was dubbed the "Oldenburg System" (see III./JG 54). This system was installed in production aircraft beginning in November 1944.
Hermann noted the following points regarding the Fw 190D-9's operational history:
The first thirty production aircraft were delivered to the unit (III./JG 54) at the beginning of October 1944.[...]In September 1944 an equipment kit was installed which raised boost pressure and increased the Jumo 213 A's emergency output from 1,750 to 1,900 h.p. The installation was carried out on-site by Junker's Tecnical Field Service (TAM). This increased emergency power could be used at altitudes to 5000 meters. At the same time, use of takeoff power (1,750 h.p.) was extended to 30 min., while authorization was given to use combat power (1,620 h.p.) without restriction.
The Junkers technical field service visited III./JG 54 monthly. In October the number of Fw 190 D-9s on strength with the Gruppe rose to 68. Of these, 53 had been converted to 1,900 h.p. and one was delivered by Focke-Wulf with the MW 50 system. The remaining 14 were in the process of being converted and completion was imminent.
[...]In its November report, Junkers noted that all the aircraft of the three new Gruppe were being converted to 1,900 h.p. and that the work was significantly more difficult at frontline airfields where there were no hangers.
By the end of December 1944 there were 183 Fw 190's in operation with the increased performance modification, and 60 more had been delivered with the MW 50 system and were at the point of entering service. *
* Dietmar Hermann, Focke-Wulf Fw 190 "Long Nose", (Schiffer, Atglen, PA, 2003)
Donald Caldwell wrote of the FW 190 D-9’s operational debut in his The JG 26 War Diary Volume Two 1943-1945 (pages 388 – 399):
17 December: The Second Gruppe pilots returned to the front and their new base at Nördhorn-Clausheide in seventy-four Fw 190D-9s, their numbers bolstered by twenty brand-new pilots. The pilot’s opinions of the “long-nosed Dora”, or Dora-9, as it was variously nicknamed, were mixed. The new model was intended to correct the Fw 190’s most glaring weakness, its poor high altitude performance. What came out of Kurt Tank’s shop was a compromise. Tank did not like the liquid-cooled Jumo 213A engine, but it was the best choice available. The long in-line engine had to be balanced by a lengthened rear fuselage to maintain the proper center of gravity, making the Fw 190D four feet longer than the Fw 190A. The new airplane lacked the high turn rate and incredible rate of roll of its close-coupled radial-engined predecessor. It was a bit faster, however, with a maximum speed of 680 km/h (422 mph) at 6600 meters (21,650 feet).Its 2240 horespower with methanol-water injection (MW 50) gave it an excellent acceleration in combat situations. It also climbed and dived more rapidly than the Fw 190A, and so proved well suited to the dive-and-zoom ambush tactics favored by the Schlageter pilots. Many of the early models were not equipped with tanks for methanol, which was in very short supply in any event. At low altitude, the top speed and acceleration of these examples were inferior to those of Allied fighters. Hans Hartigs recalled that only one of the first batch of Dora-9s received by the First Gruppe had methanol-water injection, and the rest had a top speed of only 590 km/h (360 mph).
18 December: The First Gruppe reported a strength of 52 190As and 28 Fw 190 D-9’s… The Second Gruppe flew its first mission in its Dora-9s, but failed to contact the enemy.
23 December: The Second Gruppe flew its first Fw 190D-9 mission.
24 December: The first combat mission for the new Fw 190 D-9s of the First Gruppe was an attempted interception of the heavy bombers.
25 December: The First Gruppe reported in the morning that only nine of its Focke-Wulfs were serviceable. The Stab and the 2nd and 3rd Staffeln were taken off operations to train in the Fw 190 D-9.
III/JG 54 returned to the combat zone, still led by Hptm. Robert Weiss, a member of JG 26 back in the glory day on the Kanalfront. […] The unit had been built up to its full strength of sixty-eight FW 190D-9s.
26 December: The biggest news the returning pilots had for their comrades was the Mustang’s superiority in speed and acceleration to their Dora 9s.
27 December: Despite its long absence from the front for training, there were still doubts as to the combat-worthiness of III/JG 54. Today a familiarization flight over Münster basin was ordered for all four of the Staffeln. […] III/JG 54 lost five aircraft destroyed and one damaged; three pilots were killed and two were injured.
29 December: The First Gruppe stood down to conduct intensive training in their Fw 190D-9s; 120 flights were made... The Green Hearts were fully engaged today; this would go down in the history of III/JG 54 as its schwarze Tag (black day).
Flugzeugbestand und Bewegungsmeldungen
| Actual Strength First of the Month |
Incoming | Outgoing | Actual Strength Last of Month |
|||||||||
| Date | Number | Model | Total | New Production |
Repaired | From Other Units | Total | Enemy Action | Other Causes | Overhaul | To Other Units | Number |
| Stab/JG2 | ||||||||||||
| 11.44 | 0 | Fw 190D-9 | 1 | 1 | - | - | - | - | - | - | - | 1 |
| 12.44 | 1 | Fw 190D-9 | 3 | 2 | - | 1 | - | - | - | - | - | 4 |
| I./JG2 | ||||||||||||
| 12.44 | 0 | Fw 190D-9 | 54 | 54 | - | - | 16 | 3 | 11 | 1 | 1 | 38 |
| III./JG2 | ||||||||||||
| 12.44 | 0 | Fw 190D-9 | 2 | 2 | - | - | - | - | - | - | - | 2 |
| Stab/JG26 | ||||||||||||
| 12.44 | 0 | Fw 190D-9 | 1 | 1 | - | - | - | - | - | - | - | 1 |
| I./JG26 | ||||||||||||
| 12.44 | 0 | Fw 190D-9 | 63 | 62 | 1 | - | 14 | 9 | 5 | - | - | 49 |
| II./JG26 | ||||||||||||
| 11.44 | 0 | Fw 190D-9 | 55 | 55 | - | - | - | - | - | - | - | 55 |
| 12.44 | 55 | Fw 190D-9 | 11 | 11 | - | - | 27 | 9 | 15 | 3 | - | 39 |
| III./JG26 | ||||||||||||
| 12.44 | 0 | Fw 190D-9 | 5 | 5 | - | - | 4 | - | - | - | 4 | 1 |
| III./JG54 | ||||||||||||
| 9.44 | 0 | Fw 190D-9 | 18 | 18 | - | - | - | - | - | - | - | 18 |
| 10.44 | 18 | Fw 190D-9 | 46 | 45 | 1 | - | 8 | 6 | 2 | - | - | 56 |
| 11.44 | 56 | Fw 190D-9 | 22 | 20 | 2 | - | 10 | 2 | 7 | 1 | - | 68 |
| 12.44 | 68 | Fw 190D-9 | 7 | 4 | 3 | - | 26 | 21 | 5 | - | - | 49 |
| As of 31 December 1944 there were 183 FW 190 D-9's on strength with operational units.
On 1 January 1945 at least 64 Fw 190 D-9's from JG 2, JG 26 and JG 54 were lost during Operation Bodenplatte. It was recorded by the Gen.Qu. that as of 10/11 April 1945, JG 2 and JG 26 taken together had 138 FW 190's on strength of which 70 were serviceable. |
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Miscellaneous
Flugbericht Fw 190/0043 V 21 Nr. 1, Focke-Wulf Flugzeugbau G.m.b.H., 9.5.1944
Focke-Wulf Flugzeugbau G.M.B.H., Abt.: Flugmechanik-L, Level Speed, 11.3.45
Focke-Wulf Flugzeugbau G.M.B.H., Abt.: Flugmechanik-L, Climb Performance, 11.3.45
Focke-Wulf Flugzeugbau, Horizontalgeschwindigkeit über der Flughöhe mit Sondernotleistung, 15.12.44
Focke-Wulf Flugzeugbau, Horizontalgeschwindigkeit über der Flughöhe mit Sondernotleistung, 3.1.45
Focke-Wulf Flugzeugbau, Climb and Level Speed Performance with C3 Fuel
Einmotorige Jäger: Leistungsdaten, 1.10.1944
Einsatzbereitschaft der flg.Verbände im Bereich Lfl.Kdo.Reich, Stand 12.4.1945
Jumo 213A Motorleistungen
Widerstandsdaten von Flugzeugen, December 1944
