Flettner

The F-series was preceded by a series of V-type aircraft since the summer of 1940 – the known ones are:
V 21 WNr. 5602 CE + BN,
V 22 WNr. 1800 CE + BO,
V 23 WNr. 5603 CE + BP,
V 24 WNr. 5604 VK + AB
and a small F-0 series.
Bf 109 F-1
In November 1940, the first F-series aircraft reached front-line units;
the first recipients were the squadron staffs of JG 26 and 51. Most likely However, these aircraft were not yet the first to go into series production, but rather some of the F-0s that were delivered to the front-line units for testing. The aircraft that reached the JG 51 staff, whose appearance already completely resembled that of the production aircraft, had the Stammkennzeichen SG + GV, WerkNr. 570?, and SG + ??, WerkNr. also unknown. In contrast, the aircraft flown by the JG 26 staff, similar to the F-0 with the Stammkennzeichen PH + BE, still had the old E-series supercharger intake manifold.
The first F-1s only appear in the loss records considerably later, in June 1941. After that,F-1s were flown by the III. and IV./JG 51, II./JG 53, and l./JG 3. Later, individual F-1s were transferred to JGr. Ost. The first known loss of an F-1 occurred on June 5, 1941, with 12./JG 51, when Lt. Wiest, with WerkNr. 5637, was killed in a foggy crash.
However, since the loss reports from spring 1941 are incomplete regarding model series and serial numbers, or even contain no information at all, the above list of units should be viewed with caution; in fact, other units may have received the F-1, and it can also be assumed that losses had already occurred among these aircraft.
All things considered, it seems closest to the truth to postpone the start of delivery of the F-1 series to March 1941 at the same time as that of the F-2 series.
The available documents suggest that Conclusion: Only very few F-1s were built, probably not much more than 50 aircraft in total. These received their serial numbers from the range 5600 - 5750, although in addition to F-1s, some V-type aircraft and numerous F-2s also appeared within this serial number block.
Due to the lack of reliable documentation on the F-1, the details of the F-series will be illustrated using the following F-2.
Bf 109 F-2
The F-2 was delivered in March 1941 as the first large-scale production aircraft of the F-series. Among the first units to be equipped with them were III./JG 2, III./JG 3, III./JG 26, I./JG 51, and II./JG 53. One of the first F-2s was lost on April 24, 1941, when Fw. Hähnel of 7./JG 3 crashed near Rheda during a training flight. The F-2 was deployed
flown with the I., III./JG 1,1., II., III., 10./JG 2, I., II., lll./JG 3, ll./JG 5, III., 10./JG 26.1., II., III.,IV./JG 51.1., II., lll./JG 52.1., II., 10./JG 53.1., II., lll./JG 54, II., lll./JG 77, JGr. Siid, JGr. East, Jabo Gr. Africa (also referred to as Jabo-Gr. OB Siid), 2.(H)/14, NAG 4, III/KG 66. Later, numerous training units also received the F-2, which have since been replaced by newer models; however, these units will not be listed here.
The serial numbers of the F-2 series were in the serial number blocks
5400-5558,
5600-5750 (in addition to V-machines and F-0),
6600-6850,
8050-8330,
8900-9000,
9150-9350,
9500-10000,
12600-13000.
Like the F-1, the F-2 received a DB 601 N engine, which drove a VDM three-blade all-metal propeller with a diameter of three meters and whose blades were slightly wider than those of the E series. The propeller cowling was considerably larger than on the E series and fitted much more seamlessly with the also revised engine cowling. The exhaust nozzles on both sides of the engine were framed slightly differently, with the left row having a deflector plate from above.
which was intended to prevent exhaust fumes from entering the supercharger intake manifold mounted above it. The intake manifold itself was significantly modified and now protruded in an elbow shape from the left side of the engine cowling; at its inlet, the intake manifold was circular in profile.
The cabin was only slightly changed compared to the E series. According to the manual for the Bf 109 F, the front lower triangular window on the right side of all aircraft was to be replaced by a sheet metal panel into which an ejection port for flare ammunition was to be inserted; this could consist of either a single opening or a forward-facing tube.
In fact, however, the conventional glazing was retained on a number of Bf 109 Fs (presumably only the F-1 and F-2). -
The folding hood was fitted with a two-piece all-metal head armor as standard. An additional armored screen could be added later in front of the windshield. The fuel filler neck was relocated from the rear of the fuselage to the left under the cabin.
The tail assembly was significantly modified, and now no longer had struts for the horizontal stabilizer. Since the modified tail assembly was initially too light, which had led to a number of crashes, two narrow, horizontal metal bands were subsequently added to both sides of the fuselage end (at the attachment point of the tail boom, Cyber Frame 9) for stiffening. These stiffeners were still missing on the F-0, while it is unknown to what extent they were installed on the F-1. Such externally visible reinforcements were, in any case, visible on most F-2s. The rudder was now operated by cables that were no longer visible externally.
The tailwheel, measuring 290 x 110 mm, was semi-retractable, so that even in flight, a portion of the tailwheel always remained visible in the tail shaft.
The most striking difference between the F-series wings and those of the E-series was the rounded wingtips. The pitot tube was now installed at the front end of the left wing tip. The trailing edge flaps had also been fundamentally modified; the landing flaps now only reached as far as the wing radiators. Behind the wing radiators, whose shape was also significantly revised, there were now slotted radiator flaps that served as additional landing flaps.
A large portion of the F-2 series still received square wheel wells for the landing wheels, as was familiar from the E series. Others received circular wheel wells, which would remain a characteristic feature of the F series. The landing wheels remained unchanged at 650 x 150 and retained spoked rims. The wheel well covers on the struts were slightly modified. The F-2 was armed with an MG 151/15 as a motor cannon instead of the F-1's MG FF/M, as well as the two MG 17s above the engine, which remained unchanged. The F-series radio system consisted of a FuG Vila and a FuG 25; some F-2s, however, appear to have already been equipped with a FuG 25a, whose rod antenna is visible under the fuselage on the right. protruded behind frame 3, as was already observed, for example, on aircraft of III/JG 51 in June 1941.
A number of F-2s were equipped with drop devices for either one 250 kg bomb or four 50 kg bombs; aircraft thus equipped were designated F-2/B. The range extension with a 300 l auxiliary tank under the fuselage and a feed pump for emptying the auxiliary tank was widespread; the suspension for the jettisonable tank was mounted between the struts, offset 40 mm to the left of the flight direction. The range extension was reportedly designated R5. The F-2 was intended for the installation of a GM-1 nitro-oxide injection system, which would lead to the designation F-2/Z. However, no F-2 is known to have actually been equipped with this system. The same applies to the installation of a trop system for use in the Mediterranean region; an F-2 trop series is also unknown. However, individual F-2s were subsequently retrofitted with a sand separator, although this was usually done in conjunction with other upgrades - such as the installation
an image device - may have happened; one such "F-2 trop" was WerkNr. 5445, which flew as the "black 5" with 2.(H)/14.
Bf 109 F-3
There was no F-3 series. A Bf 109 F-3 was planned, but it clearly never went into series production.
Bf 109 F-4
Shortly after the F-2, the F-4, the second large-scale version of the F series, was delivered; the first F-4s were delivered to front-line units in June 1941. One of the first F-4 losses was suffered on July 1, 1941, by 8./JG 52, when Olt. Lössnitz with WerkNr. 7020 died in a crash resulting from ground contact. The F-4 was flown in action with the II.,
111., IV./JG 1, I., II., III., 10./JG 2, l„ II., lll./JG 3,
11., III., IV./JG 5.1., III., 10./JG 26.1., II., III., 10./
JG 27, II., lll./JG 51, I., II., lll./JG 52, I., II., III.,
10./JG 53.1., II., lll./JG 54.1., II., lll./JG 77, JGr.
East, JGr. Siid, Egr. West, Jabo-Gr. Africa,
4.(H)/12, 2.(H)/14, NAG 2, 4, (F)/100, (F)/122,
(F)/123, Reconnaissance Group Ob.d.L.
The F-4s received their serial numbers from the Blocks
7000-7700,
8330-8900,
10000-10300,
13000-13400.
The F-4 differed only very slightly from the F-2 externally. Instead of the DB
601 N, which required 100 or 96 octane C3 gasoline, the F-4 received the improved DB 601 E engine, which again ran on 87 octane B4 gasoline; this was only visible externally by the corresponding triangle under the fuel filler neck.
During series production of the F-4 series, the turbocharger intake manifold was modified again. While the first F-4s from serial number blocks 7000 and 8330 continued to be built with the F-2 intake manifold, the aircraft manufactured from batches 10000 and 13000, as well as the F-4trop from batch 8330, received a new design with a noticeably larger diameter and a more curved shape, tapering again towards the intake. This shape of the intake manifold remained unchanged well into the G series. More frequently than on the F-2, the stiffeners on the F-4's tailplane were not mounted on the outside; nevertheless, there were a significant number of F-4s that continued to be built with the stiffeners mounted under the horizontal stabilizer. However, this appears to have been limited to the early construction lots 7000 and 8330 to be, although they were already partially missing there too.
The additional armored glass was also visible more frequently on the F-4 than on the F-2; however, it was by no means fitted as standard equipment
and therefore cannot be used as a distinguishing feature from the F-2 series.
nstead of the MG 151/15, the F-4 received the MG 151/20, bored out to 2 cm caliber, as its motor cannon, although this was not externally visible. The F-4 ultimately appears to have only received wings with round wheel wells as standard equipment.
Essentially the same upgrade options were available for the F-4 as for the F-2. The F-4 also featured the addition of drop pods for either one 250 kg bomb or four 50 kg bombs, known as the F-4/B. The range extension was also widely used.Furthermore, a whole series of F-4s actually received GM-1 injection and thus became F-4/Zs. The installation of the GM-1 system was most clearly visible externally in the enlarged oil cooler under the engine – possibly the Fo 870 oil cooler standard on the early Bf 109 Gs was already in use here. In addition, some aircraft featured a propeller with significantly wider blades. One of the more famous pilots to die in an accident involving an F-4/Z was Captain von Werra, commander of l./JG 53, who crashed into the sea and drowned off the Dutch coast on October 25, 1941, as a result of engine failure on his WerkNr.
7285. In 1942, some F-4s received two MG 151/15s in nacelle-shaped fairings under the wings, outside the wheel wells, as the R1 upgrade kit. The installation of this additional armament appears to have been rare and is documented so far only in the case of l./JG 52. In contrast, the preparation of F-4s for use in the Mediterranean as F-4 trop was widespread. For this purpose, a cylindrical sand separator was mounted in front of the supercharger intake manifold, which was braced against the engine cowling at the front with two thin struts and attached to the intake manifold inlet ring at the rear with pins. The sand separator could be closed by two shell-shaped flaps at its front end; in flight, these flaps were open, while While they were to remain closed on the ground and during flight near the ground. The shell flaps were operated via a Bowden cable, the handle of which was attached to the instrument panel in the cabin. The sand separator could only be installed in conjunction with the enlarged intake manifold of the late F-4.
The trop equipment was also supposed to include whitewall tires for protection against solar radiation, but this was mostly omitted. The installation of the additional armored windshield was comparatively rare on the F-4 trop, which was possibly due to the dusty conditions in North Africa.
A number of F-4s went to reconnaissance units and were equipped with a camera system for this purpose. Little is known about the details of this conversion and its designation, especially since the loss records of the units in question uniformly refer only to F-4s without specifying any specific to provide further information on the rust conditions of the aircraft. Nevertheless, although without the corresponding serial numbers, a whole series of Bf 109 Fs are known that reveal the installation of an imaging system in the underside of the fuselage between frames 2 and 3. This was most likely (or in some cases, certainly) an Rb 50/30 camera. The camera was mounted vertically behind the pilot's seat and fed with the corresponding film cassettes through the luggage hatch in the rear cabin wall.
Bf 109 F-5 and F-6
These two series were supposedly two slightly different reconnaissance versions. However, nothing concrete is known about either. The existing documentation for the F series indicates that It clearly shows that both versions were not built in large series with their own serial number blocks; rather, not a single aircraft with this series designation is known based on its serial number. Likewise, there is no tangible indication in manuals, etc., of the actual existence of these series. Moreover, since the loss reports from reconnaissance units only indicate the loss of F-2s or F-4s, it seems unlikely that there was a Bf 109 F-5 or F-6.
The Bf 109 F-6/U is, after all, a fantasy designation conceived at the unit level; behind this designation lies an F-2 with the serial number 6570, converted according to the wishes of Lt. Colonel Galland. , which had subsequently received two MG FF as wing armament