backbone of its units until the spring 1941. From

the invasion of Poland through the Sitzkrieg

on the Western Front, the invasion of Norway,

the Battle of France and the Battle of Britain,

the Bf 109E ensured the technical and tactical

superiority of the Luftwaffe over its opponents.

After the Battle of Britain in the autumn of 1940

and in the winter months of the following year,

however, it became increasingly clear that the

time was ripe to replace the Emils with a more

potent successor.

Bf 109F

This would become the Bf 109F, the development

of which had in fact already begun during the

preparation for series production of the Bf 109E

in the autumn of 1938. The new project was

designed around the new DB 601E engine with an

estimated maximum power of 1350 hp, compared

to 1055 hp for the DB 601A engine. In addition to

the use of a more powerful engine, the intention

of the design team led by chief designer Robert

Lusser was the overall aerodynamic refinement

of the airframe, combined with the introduction

of a number of technical improvements. It

saw the light of day by way of a complicated

development, leading through prototypes and

the pre-production Bf 109F-0, built mostly

around the Bf 109E airframe and still carrying

significant elements of the original design. In

summary, all design changes were reflected in

the first series version, the Bf 109F-1, radically

different in shape from both the Bf 109E and the

prototypes and the pre-production Bf 109F-0.

Since the DB 601E engine was not yet available

during the long development of the various

concepts incorporated into the new design, the

prototypes and pre-production Bf 109F-0 were

powered by DB 601A engines, as was most of the

Bf 109E production. Production Bf 109F-1 and F-2

aircraft were powered by DB 601N engines, and

only the Bf 109 F-4 version received the planned

DB 601E. Before we deal with the development

of individual versions of the Bf 109F, it will be

appropriate to first familiarize ourselves with

the development of the power egg, the DB 601

engine, and also the evolution of the engine

cooling system.

Photo: SDASM


Bf 109 F-0 WNr. 5604 VK+AB. The aircraft with the DB 601 A engine already had the compressor intake with

a circular cross-section. It was used to test the newly designed glycol cooler flaps combined with landing flaps.

The wing still had the straight ends of the Bf 109E.

worked its way up to 1036 hp in the DB 600 Ga

version. The first Bf 110 V1 prototype with DB 600

engines reached a speed of 505 km/h (314mph)

on May 12, 1936. The DB 600 of various versions

also powered the first versions of the He 111 B, G,

etc. However, problems with the supply of these

engines led to their replacement by more readily

available units, mainly the JUMO 210 engine,

which in the D version also powered the first

versions of the Bf 109B, C and D.

DB 601A

The fundamental innovation of direct fuel

injection into the cylinders of the DB 601

series made a significant contribution to the

advancement of the line and in the further

development of the Bf 109 and Bf 110. The DB

601Aa, production of which began in March,

1937, had the same displacement as the DB 600

at 33.9 liters ,and the compression ratio of 6.8:1

was also the same. Also unchanged were the

bore and stroke of the cylinders (bore 150 mm,

stroke 160 mm). The DB 601A used 87 octane B4

gasoline, introduced as the standard aviation

gasoline in early 1939. Maximum power output

of 1160 hp (1175 PS) at 2500 rpm was achieved

by the DB 601A at an altitude of 1700m (5577ft).

However, this output was only achieved for

a short time when the engine's filling pressure

was increased to 1.40 atm. The use of boost was

limited to one minute. On the ground, the highest

power with the same parameters was 1085 hp

(1100 PS). At a filling pressure of 1.30 atm and

2400 rpm, the highest (combat) power on the

ground was 986 hp (990 PS) and at an altitude of

2100m (6890ft), this was 1055 hp (1070 PS).

DB 601N

In the following version, the DB 601N, higher

performance was achieved by increasing the

compression ratio to 8.1:1 and introducing 100

octane C3 aviation fuel. The bore and stroke of

the cylinders remained the same as in the DB

601A and DB 600. Using an emergency boost

pressure of 1.42 atm at 2,600 RPM, 1,321 hp (1340

PS) could be produced at an altitude of 2,100 m

and 1,233 hp (1250 PS) on the ground. The use

of boost was possible for three minutes. Combat

performance at 1.30 atm boost pressure and

2400 RPM provided 1,168 hp (1,185 PS) at 2,100 m

and 1,085 hp (1,100 PS) at sea level.

DB 600

The DB 601 engine was a development of the DB

600 carburetor equipped engine, development of

which began in July 1933. It was a liquid-cooled

inline turbocharged inverted twelve-cylinder

unit of 33.9 L displacement, with a single-stage

supercharger and carburetor. In the A version,

it offered 986 hp, with gradual development it

June 2023

Photo: Bundesarchiv




Bf 109F

Ground crew maintaining the weapons of Bf 109 F of JG 54 “Grünherz” on the Eastern Front in 1942.

INFO Eduard