Friday, 21 July 2017

Fw 190 versus Bf 109 Friedrich Rechlin test report - did the Focke Wulf 190 really pose a problem for the RAF in 1941 ?

"..When the German Focke Wulf Fw190 fighter burst onto the scene over France in 1941 it took the RAF by surprise, outperforming the Spitfire Mk V. At the time the RAF described the performance gap as a quantum leap.."

There is a lot of nonsense written on the Net and elsewhere about the arrival into service of the Focke Wulf 190. It is possible to read how it swept the RAF from the skies over northern France, how it managed to put the brakes on the RAF's 'Non-Stop Offensive', even how various RAF service orders curtailed incursions over France in 1941 for fear of coming up against the new 'super-fighter'  - I'm afraid all of that simply does not stand up to examination. Incidentally the quote above is from the latest Fw 190 publication in English - the Haynes "Owners Manual"..

Above;  Fw 190 A-1 "Brown 13" of 6./ JG 26. II./JG 26 was the first unit to receive the new fighter during the summer of 1941. Note the sheen of the paint finish - early reports from JG 26 complained - among other issues - of the poor quality finish on their Fw 190s and stated that simply polishing the upper surfaces was sufficient to increase top speed ( photo via Crow, text reference in Le Focke Wulf 190, Lorant, page 94)

Let's be clear.  Arriving in the Channel Front Gruppen from mid-1941, the Focke Wulf 190 posed no problem for the RAF in 1941. In the first combat with the RAF the JG 26 pilots won 2-0, downing two Spitfires without loss. The Fw 190 A-1 was considered better than the Spitfire IIb in almost all respects. But the Germans had serious problems with the new type. Reliability of the early 1560 hp BMW 801 C engine was poor from the start and it took time to sort out. The early trials of the Fw 190 were horrendous with BMW and Focke Wulf at logger-heads over a variety of technical issues. The type's gradual introduction into service in the latter half of 1941 over the Channel coast resulted in some painful losses for the Germans themselves - including leading aces. To some the Fw 190 appeared to be no better than the Bf 109 F it was largely intended to supplant in the race for fighter dominance. The Germans' own comparison trials demonstrate this  - but are of course mostly unexploited by non-German speaking authors.

Above;  page two of a Rechlin report detailing comparison flights - Vergleichsfliegen -between the Bf 109 F-4 and FW 190 A-2 dated 10 December 1941 - source: BAMA Freiburg via Note that this page states clearly the test flights and their evaluation were carried out by a Luftwaffe 'test' detachment incorporating the experiences and findings of combat pilots in Jagdgeschwader 26. It also clearly indicates that the test flights were not performed with special aircraft, but rather standard series machines at full combat weight..('mit vollem Einsatzgewicht').

In the Rechlin report the Fw 190 A 2 is flown against the Bf 109 F-4. The first variants of the Friedrich appeared in late 1940 and by early 1941 the F-2 was being delivered. By May 1941 production of the F-4 started and the variant entered service in June 1941, with the first loss reported on 1 July 1941 (a machine in JG 52 service quoted in Prien 'Bf 109 F/G/K').   For the RAF and by way of comparison, the Spitfire V entered service in Feb 1941 (one squadron) and a further four squadrons in May. The Bf 109 F-4 was the upgraded variant of the Friedrich powered by the new DB 601 E. Initially the 601 E could only be operated under certain restrictions (Notleistung was not allowed), the aircraft was capable of attaining 635 kmh on next best rating (Steig Kampfleistung). The F-4 started to appear in numbers from July/August of 1941 and by February 1942 - with no restrictions - the aircraft handbook indicates upper speeds attained of some 670 km/h.

 In series production from June of 1941, only one hundred or so Fw 190 A-1s had been completed by late 1941 when the A-2 went into production. This was the variant tested at Rechlin by the test detachment including experienced aviators from JG 26 who had flown the type in combat. Comparison flight tests produced the following results.

The Fw 190 A 2 is not quite as fast as the F-4 and this becomes more apparent at higher altitudes, the difference amounting to as much as 20 km/h. At low level the Fw 190 may be slightly faster. Dive-performance on the other hand according to the report is excellent with the Fw 190 always able to pull away at all heights.

Climb performance of the Fw 190 is considerably inferior - "..stark unterlegen " - to the Bf 109 F-4, taking some six minutes longer to reach 10,000 m. The A 2's performance is 50% poorer at altitude -over 30,000 ft - than the Bf 109 F-4

..While roll rate is considered excellent and reprsents good progress in the Fw 190, it could not be established conclusively whether the Fw 190 can out-turn the Bf 109..

engine comparison

The engine powering the Fw 190 A 2 is " unreliable at the present time that in the view of Oberst Galland it has only limited combat capability and currently no missions over the Channel into England should be considered..."  (December 1941). With so many modifications required (already some 20 at the current time) on the BMW 801 C and also the 801 D it will take at least another six months to iron out the bugs..

The report clarifies two facts. On the one hand the BMW 801 C was seen as not ready for service, so many modifications being required - it had at this time an average service life of just 25 operating hours (!!). In contrast the DB 601 E was evaluated as ready for service and 'mature'. Any initial problems with the DB 601 E had been remedied by the time of the comparison flights in November/December 1941 ( 'frontreif''). The report continues by stating that the technical difficulties encountered with the Fw 190 would persist well into the new year (ie 1942) and that at that time only the F-4 of these two machines could be considered truly combat-capable ('frontreif'). In addition the 801 C ran on B4 87 octane fuel and it was not until the 801 D appeared using using C3 100 octane fuel that performance was boosted accordingly - although even this engine had restrictions until mid-late 1942!

So why does the Fw 190 enjoy the reputation through 1941 that some attribute to it?

In the comparison testing carried out at Rechlin in late 1941 between the Bf 109 F-4 and early Fw 190 A-1/A-2 the Bf 109 F-4 was assessed as a "mature" and well tested and proven design, while the Fw 190 A-1/A-2 was a new design with a new engine just reaching the front with many issues not yet ironed out, engine reliability being an obvious one. Not that a new German fighter was really a surprise either. In England, "Flight" magazine published an article in October 1940 describing the Bf 109 Emil as "..a German design which missed being a success..the Luftwaffe probably expected to bomb its way to a quick victory..(so) it is unlikely that Germany will rest content with the Me 109 as its only single-seat fighter.."  The Friedrich when it arrived on the scene presented a number of enhancements over the successive improvements introduced to the venerable "Emil" with which the Jagdwaffe had gone to war over Poland. The basic airframe had undergone a redesign with the aim of improving aerodynamic efficiency - especially in the area of the wing and tailplane. Both spinner and wingtips were rounded and more streamlined and the Emil's out-moded horizontal stabilizer brace supports had been eliminated. In addition the tailwheel was now fully retractable. However the Friedrich did not feature wing armament and weight of fire was thus reduced in comparison to the older sub-type.

The F-4 was of course a better machine than the Emil but it was also better than the F-1/2 - and a difficult opponent for the Spitfire V - and as the report above makes clear it was easily as good as the new Fw 190. The 'advantage' of the Fw 190 lay in the fact that it was visually different enough to make identification easy. Here was a new type for which new tactics might have to be developed. No RAF pilot could tell an early Friedrich from a late one visually and even though the RAF very quickly had an example of the Friedrich to evaluate when the Kommandeur of I./ JG 26 landed near Dover on 10 July 1941 it was a while before any test data could be passed on to front-line pilots. And with the DB 601 E initially operating under restrictions for a few months, then its initial introduction did not have that same impact. Elsewhere Hooten looks at Fighter Command's losses over France vs the Friedrich up to late 1941 and compares them with RAF losses in the four months up to mid-1942 with the Channel Front Geschwader almost fully re-equipped with the Fw 190 and concludes that RAF losses over France were falling following the introduction of the Fw 190.

The Fw 190 had a few performance advantages that were readily apparent and especially useful in combat, like the rapid rate of roll and dive performance - ".. die Rollwendigkeit ..die sich insbesondere im Luftkampf stark bemerkbar machte..."  Nor was it announced to the British public until the spring of 1942. However, it was not until that time in 1942 and the introduction of the A-3 with the improved reliability of the BMW 801 D-2 with increased output from 1560 hp to 1750 hp and improved armament that the Fw 190 became a better fighter and not until the A-5 that the Fw 190 became a mature design design, having solved overheating and vibration issues better with a nose-plug extension and MW 50 power boosting. Taken from the very end of Dietmar Hermann's article in Jet and Prop 3/2012; "In this form it was surely the highest performing fighter in the west and the east 1942-1943..". But during the type's initial service it could hardly be said to have "burst on to the scene"..