HISTORY

GM-1

altitudes. To increase performance at altitudes

of up to 8,000 m (26,250ft), the water injection

system MW 50 or MW 30 was later used, which

reduced the temperature of the mixture by

evaporating the water in the cylinder, but did

not generate the necessary oxygen. This had

to be supplemented by increasing the filling

pressure with a compressor, but could no

longer produce the necessary filling pressure

at higher altitudes.

The GM-1 system increased the DB 601N and E

engine power at 9,000 m and 2600 RPM by up to

246 hp (250 PS), and the aircraft's speed by as

much as 90 km/h. Maximum N2O injection time

was 3 minutes (Baumgartl – sources vary on

the exact numbers.

Photo: Bundesarchiv

The nitrous oxide (N2O) injection system

of the GM-1 engine cylinders allowed for

a short-term increase in engine power at

high altitudes (above 9,000m or 29,500ft). The

principle of increasing performance is that

when the mixture burns in the cylinder, nitrous

oxide is decomposed into oxygen and nitrogen.

Nitrogen cools the mixture and oxygen causes

the mixture to become lean (the mixture

contains more oxygen than fuel). Thanks

to this, it is possible to add more fuel to the

mixture, without the need to supplement the

boost pressure with the compressor, because

the necessary additional amount of oxygen

to burn the fuel in the cylinder is obtained by

the decomposition of nitrogen oxide. For this

reason, the GM-1 system was used at high

JG 27 Bf 109 F-4 Trop in North Africa. Mechanics are cleaning the barrel of the MG 151/20 cannon.

(66gal), the same that already equipped the

Bf 109E-7. The system of pumping fuel from the

auxiliary tank to the main fuel tank was based on

the principle of pressurizing the auxiliary tank

with compressed air, dispensing the need for

a fuel pump. It should be noted that photographs

of the Bf 109F-2 carrying the centerline drop

tank are very rare.

The Bf 109F-2 could also be modified for the

fighter-bomber role by installing an ETC 500/IXb

bomb rack under the fuselage to carry a 250 kg

(550lb) SC 250 aerial bomb, or an ETC 50/VIId

combined bomb rack for four 50 kg (110lb) SC

50 bombs. The designation of the bomb capable

version was Bf 109F-2/B or Bf 109F-2/Bo.

In terms of performance, H.H. Vogt states

a maximum speed of 630 km/h (390mph), and at

sea level, 528 km/h (330mph). According to Vogt,

the rate of climb is the same as that of the F-1,

17 m/s (56ft/s), a range of 700 km (430 miles),

and a service ceiling of 12,000m ((39,300 feet).

M. Baumgartl, in a performance table derived

from the British Research iInstitute R.A.E. at

Farnborough, gives a top speed at 6,629 m

(21,750 ft) 597 km/h (371 mph), 491 km/h (305

mph) at sea level. The Soviet institute NII VVS

gives a top speed 561 km/h (350mph) at 2,900m

(9,500ft) and 510 km/h (317mph) at sea level. The

British data in this case are consistent with the

German figures for the Bf 109F-1. All in all, this

would correspond to the fact that both versions,

the F-1 and F-2, were powered by the same

engine with the same performance, while the

differences in the design of the aircraft were

essentially negligible.

The F-2 also had a number of shortcomings that

manifested themselves in service. A report from

early April, 1941 by the commander of Luftflotte

2, General-Field Marshal Kesselring, described

twenty-four defects of varying degrees of

severity. These were gradually addressed on

the production line, but most were resolved

with the next production version, the Bf 109F-4.

A total of 1,586 Bf 109F-2s (Vogt) were built,

production ran in parallel at five factories: Mtt

Regensburg (228 units produced), Erla Leipzig

(219 units), AGO Oschersleben (378 units), WNF

(169 units) and Arado Warnemünde (358 units),

where production ended in August 1941.

Photo: SDASM

Bf 109F-3

This version was a direct development of the F-1,

and featured a combination of the DB 601E engine

and the MG/FF engine mounted gun. Production

was stopped after 15 aircraft had been built

after the new more powerful MG 151/20 cannon

became available.

A photo reconnaissance Bf 109 Fs from the 4.(F)/123 in 1943 at Cherbourg.

12

INFO Eduard

Bf 109F-4

Production of the final and most powerful

version of the Bf 109F, the dash-4, began at the

WNF factory in May 1941, and the Erla factory in

June. The first Bf 109F-4s arrived at front line

June 2023