The powerful and deadly Messerschmitt Bf-109 was the mainstay of the Luftwaffe’s fighter arm throughout World War II, scoring more aerial victories than any other type. Thirteen Bf 109 pilots claimed more than 200 victories apiece, while two of these ‘Experten’, ‘Bubi’ Hartmann and ‘Gerd’ Barkhorn, each shot down more than 300 enemy aircraft. In the early years of the war, the speed, handling characteristics and firepower of the Bf 109E 'Emils' gave many Allied Hurricane and Spitfire pilots a nasty shock.
With a top speed of 690 km/h (429 mph) at 7,400 m (24,280 ft), a powerful 2,000 horsepower Daimler-Benz 605D engine and a pressurized cabin, the K-4 ‘Kurfürst’ was the best and final version of the Bf-109 to see service. Armed with one 30-mm Mk 108 cannon and two 13-mm Mk 131 machine guns, the K-4’s agility made it more than a match for most Allied fighters, while its blistering firepower made it the scourge of high-flying enemy bombers.
The ‘Kurfürst’ was also no slouch in the ground-attack role, carrying either a 500 kg or a 250 kg bomb.
Jump into your K-4, get airborne and tangle with Mustangs, Spitfires and Thunderbolts, or scythe your way down through massed Flying Fortress bomber formations.
The control unit assembly consists of the horizontal stabilizer and elevators, the vertical stabilizer and rudder, the ailerons, and the flaps.
The Bf 109K-4 has a conventional control scheme with surfaces that include a vertical stabilizer, rudder, horizontal stabilizer, two elevator, two aileron, and flaps.
The flight stick can be moved forwards and backwards in conventional fashion to control the elevator. The stick can be moved 15°30' forwards and 15°30' backwards.
As the entire tailplane can be trimmed in flight by using the Horizontal Stabilizer Trim Handhwheel, elevator deflection depends on tailplane position.
The flight stick can also be moved sideways to control the ailerons in conventional fashion.
Flap position is controlled via a handwheel located to the pilot's left. The flaps position scales are drawn on root part of flaps and visible from cockpit. Flaps can be deflected from 0 to 40°, with the 40° position reserved for landing, and 20° generally used for take off. One full turn of the flap handwheel is equal to roughly 5° of flap deflection; therefore four full turns are required for the Take-Off position, and eight full turns for Landing.
Tailplane position is controlled via a handwheel located to the pilot's left alongside the flap handwheel. Cockpit indicator is provided near the handwheel, with the round window on the mechanical indicator displaying the incidence level. Negative incidence is shown with a minus sign, e.g. -2.5, while positive incidence is shown with no sign, i.e. 1 means +1.
The tailplane can be moved from +1°10' to -6°.
The aircraft is generally easy to pilot when proper control forces is applied. However, the tendency of the left wing to suddenly drop on take-off and landing is the aircraft's Achilles heel. Precise rudder input is required to counter the yaw.
The Bf 109 features retractable narrow-track landing gear. Wheels are raised and lowered hydraulically. There is also an auxiliary manual system for operating the gear.
The tailwheel on the 109 went through many changes. While many earlier variants featured a fixed tailwheel, the K-4 reintroduces the retractable type that improves high-speed performance. The tailwheel also features two small clamshell doors covering the recess when the tail-wheel was retracted.
The undercarriage is controlled by simple push buttons located on the cockpit's left-hand side.
In case of hydraulics failure, the main gear can also be lowered by pulling the emergency gear extension handle. This unlocks the shock struts which can then extend with the help of gravity and sealed air jacks.
The tailwheel is retracted simultaneously with the main gear. It can be locked or unlocked via a control rod located by the pilot's left elbow.
The Bf 109K-4 has hydraulically operated brake shoes on each of the two main wheels. Each has its own hydraulic pump and brake lines. Each wheel can be braked individually.
The entire system is conventionally operated via rudder pedals.
Most of the Bf 109s were powered by various variants of the Daimler-Benz DB 601 V12 engine, or its derivative the DB 605. Same is the case for the Bf 109 K-4.
Engine supply situation has often been a weak spot for the German aircraft industry, and it was especially felt in 1944 and 1945 as the 109K was in production. A variety of DB 605 variants were installed on production K-4s. Initial plans to use the advanced DB 605L with a two-stage supercharger were foiled with a single lucky Allied bomb that took out a high-altitude test chamber, delaying 605L deliveries by nearly a year. As it is, production 109Ks shipped with DB-605B, DB 605DC, DB-605ASC, or DB-605ASC, with some very late production K-14s finally receiving the DB 605L.
The DCS Bf 109 K-4 is modeled with the DB 605 DB engine.
The DB 605 DB could use B4 fuel which, with MW 50 Methanol Water injection equipment, generated an emergency power rating of 1,600 PS at 6,000 m (1,160 PS maximum continual at 6,600 m), and take-off power of 1,850 PS at 0 m, with a maximum supercharger boost of 1.8 ATA. The DB could also be run on higher octane C3 fuel, but use of MW 50 was forbidden.
The large advantage of the Daimler-Benz engine is its direct fuel injection. While most Allied aircraft use complex and expensive turbo superchargers that require high-octane fuel, the DB 601 and its 603 and 605 derivatives could compete with them using low-grade 87-octane fuel due to the use of direct fuel injection.
The Daimler Benz DB 605 engine has a hydraulically driven single-stage supercharger, coupled with a MW-50 Water-Methanol injection.
