Messerschmitt Bf 109 K-4

Messerschmitt · DE · first flew 1944 · fighter

The K-4 was the primary production variant of the Kurfürst series, the fastest and most powerful 109 to reach operational service, optimised for Defence of the Reich duties in late 1944.

Recognition (WEFT)

W — Wings	Low-mounted, tapered
E — Engines	1 × piston, nose-mounted
F — Fuselage	8.95 m fuselage
T — Tail	Conventional

WEFT is AircraftIQ's four-point recognition method — how it works.

Spot it by:

Enlarged, broad taller wooden tail — the tallest fin of any production 109 series
DB 605ASCM/DCM engine with MW-50 injection; large supercharger intake and prominent Beule cowl bulges
Retractable tail-wheel (distinguishing it from most Gustavs which had fixed or semi-retractable)

The tall wooden tail fin is the single most distinctive cue — noticeably taller and broader than any Gustav tail. Retractable tail-wheel (smooth fairing under rear fuselage) versus the exposed strut of earlier marks. Combined with the heavy Beule bumps and large supercharger intake, the K-4 has a more purposeful, bulkier nose profile than mid-war Gustavs.

Specifications

The Messerschmitt Bf 109 K-4 has a length of 8.95 m (29 ft).
It has a wingspan of 9.92 m (33 ft).
Its maximum speed is 727 km/h (452 mph).
Typical crew: 1.

Figures are for the representative variant described above; marks differ. See how AircraftIQ sources figures.

History

Around 1,800 K-4s built before the war ended. It was intended as a rationalised 'clean' design avoiding the proliferation of G-series field kits. Equipped with MW-50 methanol-water injection, it reached 727 km/h at altitude.

Variants

K-4 was the only production Kurfürst mark. K-2 and K-6 remained prototypes.

Where you'll see it

Luftwaffe fighter units, October 1944 to May 1945. Very few complete examples survive; restoration projects exist in Germany and the US.

Related aircraft

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