INSTRUMENT PANEL OF THE BF 109 K-4 - PART II
(6) HOMING INDICATOR AFN2 Ln 27002: The FuG 16 ZY radio (produced by Lorenz) with a frequency range of 38.4 to 42.2 MHz was used for audible communication aircraft/ground and aircraft/aircraft. 4 frequencies could be remotely set from the cockpit. A T-aerial between the tail unit and the aerial mast behind the cockpit was used for reception and a rod aerial (under the left wing) was used for transmission. With the FuG 16 ZY the ground control station was able to determine position and altitude. A homing device ZVG16 (Zielflugvorsatzgeraet) was combined with the same equipment and selectable with the switch "ZF-FT" (Zielflug - Funktelegraphie) which was part of the junction box (Anschlussdose) AD18 on the right cockpit side. The homing indicator AFN2 F 155 was mounted on the lower right side of the Blind Flying Panel. The plug Ln 27003 also contained a glow lamp Fl 26682. As far as I know this lamp was only used in connection with blind landing systems (e.g. FuBl2; as a visual indication for a beacon) which was not installed in the Me 109 K-4.
(7) ELECTRICAL INDICATOR FOR PITOT TUBE HEATING Fl 32530-7: This electrical indicator (Drehzschauzeichen) was used for pitot tube heating indication (on/off) and was installed on the the left side of the Blind Flying Panel between air speed indicator and altimeter. However, it was only installed in very few aircraft. If it was not used the hole in the panel was either left open or it was covered with a piece of sheet metal, paper, or fabric. Another variation was that the hole was not completely milled through. In case that the indicator was installed the hole could be simply penetrated as there was only a very thin layer of wood left. This variation is the one found on two surviving original Me 109 K-4 panels.
(8) FUEL AND LUBRICANT PRESSURE GAUGE Fl 20512-2: This double pressure gauge (Doppeldruckmesser) was used for indicating the fuel and lubricant pressure and was installed on the upper right side of the main instrument panel. The left, yellow marked half of the instrument had a measurement range of 0 to 2 kg/cm2 and indicated the fuel pressure. The right, reddish brown marked half had a measurement range of 0 to 10 kg/cm2 and indicated the lubricant pressure. The pressure tubes were connected to the fuel delivery pump and to the lubricant filter. A return valve was attached to the fuel pressure line. The markers on the dial of the gauge were set to 1.6 and 1.8 kg/cm2 for the fuel pressure and to 3.5 and 9.5 for the lubricant pressure (according to Bedienungsvorschrift-Fl Bf 109 K-4 part 2)
(9) RPM INDICATOR Fl 20227: This rpm indicator (Drehzahlmesser) with a measurement range of 500 to 3500 U/min was mounted on the right side of the main instrument panel. It was driven by a flexible shaft which was connected with engine. Red markings were applied to the glass which covers the dial at 2000, 2400, 2600, and 2800 U/min. These limits correspond to economy power (1.15 ata manifold pressure), maximal continuous power (1.35 ata), climb- and combat power (1.45 ata), and emergency power with methanol water operation (1.8 ata).
(10) MANIFOLD PRESSURE GAUGE Fl 20555: The manifold pressure gauge (Ladedruckmesser) with a measurement range of 0.6 to 1.8 ata (absolut pressure) was mounted on rubber shock mounts on the lower right side of the main instrument panel. The pressure tube was connected to the supercharger. It had red markings on the glass at 1.15, 1.35, 1.45 and 1.8 which correspond to he power settings metioned in (9). Some aircraft had an engine with increased mainfold pressure (up to roughly 1.9 ata). It is believed that these aircraft had a 2.5 ata manifold pressure gauge Fl 20554 instead of the 1.8 ata gauge although I do not know a photo showing such a manifold pressure gauge installed in a Bf 109 K-4 panel.
