mitsubishi db-130 manual

How good was the Messerschmitt BF 109 K-4 in combat?

An amazing fighter it showed true engineering brilliance, esp. at this late time of the war. As fast, 440 mph, as the P-51Ds and P-47Ds, (although not as fast as the P-47Ms, 470 mph,) it could turn on a dime, and man, could it climb! Initial rate of climb was 850 m (2,790 ft)/min, without MW 50, and 1,080 m (3,540 ft)/min, using MW 50! (Methane-Water injection.) It was very short ranged at 350 miles, but was on the defensive so not a big issue. But its diving and rolling abilities were limited, making it not the best “energy” fighter with “Boom and Zoom,” diving ambush tactics… But most of all it was limited by the increasingly poor German pilot “training” with fewer and fewer good teachers, and a critical shortage of fuel to even fly the Luftwaffe let alone teach their new pilots. Beautiful new Fw190Ds and Bf 109Ks were piloted by green boys that could barely keep them aloft, let alone fly them with any ability. But in the hand of the occasional surviving German “experten”, the Bf 109K could be devastating. The Bf 109K arrived in late Aug-early Sept ‘44, with a redone fuselage for better aerodynamics, larger tail fin surface with two trim tabs on the rudder, bigger prop/elongated spinner, and (thank God!) a new canopy with far increased viability, increased hood height. (Although still cramped and disorganized compared to the best like the P-47 and P-51s cockpit.) The plane was equipped with a wooden keel, a retractable tail wheel on an elongated strut, a FuG.16ZY radio, a Revi-16B gun sight, and a FuG.25A transponder, with a direction finder antenna behind the cockpit and an additional antenna under the left wing. And mainly, the Daimler-Benz DB 605 D/C -ASCM, which had an adjusting screw allowing the engine to use either B4 + MW 50 Methanol Water injection equipment or C3 fuel (DB 605 DB) or C3 fuel, with or without MW 50 and up to 2000 hp, (1,973 HP), finally able to pretty much match the P-51s and 47s. Two months later in November they added cockpit pressurisation. K-4 drawings: (Since we’re talking about the Bf 109K: A word about ,Climb Rate,: The Bf 109K was one of the premier climbers of WWII, to respond to Allied threats and to reach the high altitudes the Allied bombers and escort fighters were already flying at. Climb rate was most important for interceptor aircraft tasked with quickly getting to the level of intruding enemy aircraft. When an aircraft climbs it gains potential energy, which means it needs spare available power. The ,specific excess power, of an aircraft is equal to V/W(T-D) where V is airspeed, W is weight, T is thrust and D is drag. Note that lift isn't anywhere in this equation! Provided that the plane has adequate lift to stay in the air and its wings are reasonably efficient at generating lift so that the D term doesn't get too high, a plane with stubby wings can be quite the climber! The Mitsubishi J2M Raiden is an excellent example of what a fighter optimized for climb rate looked like. The J2M was to be a strictly local-defense intercepter, intended to counter the threat of high-altitude bomber raids, and thus relied on speed, climb performance, and armament at the expense of manoeuvrability. The J2M was a sleek, but stubby craft with its over-sized ,Mitsubishi Kasei, engine buried behind a long cowling, cooled by an intake fan and connected to the propeller with an extension shaft. Primarily designed to defend against the ,Boeing B-29 Superfortress,, the lack of a turbocharger handicapped the aircraft at high altitude. However, its four-cannon armament supplied effective firepower and the use of dive and zoom tactics allowed it to score…occasionally. The J2M had a very aerodynamically clean design, somewhat at the expense of pilot visibility and decidedly at the expense of turn rate. The airframe was comparatively light, somewhat at the expense of firepower and at great expense to fuel capacity. Surprisingly for a Japanese aircraft, there was actually some pilot armour. The engine was, naturally, the most powerful available at the time. The wings, in addition to being somewhat small by Japanese standards, had laminar-flow airfoils that sacrificed maximum lift for lower drag. The end result was an aircraft that was the polar opposite of the comparatively slow, long-ranged and agile A6M zero-sen fighters that IJN pilots were used to! But it certainly worked. The J2M was one of the fastest-climbing piston engine aircraft of the war, comparable to the F8F Bearcat or the Bf 109K. The design requirements for climb rate were practically the same as the design requirements for acceleration, and could generally be reconciled with the design requirements for dive performance and top speed. The design requirements for turn rate were very difficult to reconcile with the design requirements for climb rate. Anyway…) Bf 109K Kurfurst, (letter “I” was not used by the Ministry of Aviation, and “J” was assigned to a modification of a fighter with a Hispano-Suiza engine), was a modified version of the Bf 109G-10, which received a number of factory-installed kits used on series G aircraft and some aerodynamic improvements. The first aircraft left the assembly line in October 1944. These were the Bf 109K-2 and K-4, differing only in the cabin pressurization on the latter. The last aircraft of the K-4 series received a 30-mm MK-103 cannon instead of the MK-108 propulsion cannon, but the 65-mm cover that covered the gun barrel made replacing the latter in the field with a non-trivial task. The MK-103 cannon was also installed on the Bf 109K-6, the main task of which was the fight against bombers, for which it carried two more 30-mm MK-103 in underwing gondolas, however, the fuselage MG.151 were again replaced by 13-mm machine guns MG.131. Deliveries of the Bf 109K-6 to fighter groups began in January 1945, but before the collapse of the Third Reich, only a few of these machines arrived - given that its takeoff weight (3600 kg) made it so poorly controlled, it actually was happiness for the Luftwaffe pilots in the face of complete air superiority of the Allies. Bf.109K-4 Specification Crew: 1 Dimensions: Wing span, m 10.00 Length, m 8.85 Height, m 2.50 Wing area, m² 16.10 Powerplant: PE Daimler-Benz DB-605ASCM, hp 2000 Weight, kg: Loaded weight: 3100 Maximum takeoff weight: 3400 Performance: Maximum speed at sea level,: km/h 605 (375 mph) Maximum speed at altitude 8700m,: km/h over 700 (440 mph) Maximum rate of climb, m/min: 1470 (4823 feet per minute) Service ceiling, m 12500 (41,000 feet) Service range, km 570 (354 miles) Armament: 30-mm MK-103 or MK108 cannon with 60 cartridges, 2 × 15-mm MG-151 cannon with 200 cartridges on each one The Bf 109K-14 received the long-awaited DB603L engine with a two-stage supercharger. One successful Allied bomb the year before had disabled the DB605L's thin atmosphere test chamber, which proved to be the main reason for the delay in engine deliveries for the Bf 109K. The DB605L engine ran on 96-octane C3 gasoline and used the afterburner MW-50, which provided 1700 hp during takeoff and 1725 hp at an altitude of 1500 m. At an altitude of 9500 m, the power reached 1350 hp in combat mode and 1150 hp, when climbing. If the Bf 109K-4 developed a speed of 723 km/h at an altitude of 6,000 m, then the Bf 109K-14 could maintain such a speed at an altitude of 11,500 m. When the Allies crossed the Rhine, the number of Bf 109s in the Luftwaffe was still quite large - about 800 machines equally divided into the G and K series, of which 80% were combat-ready. But in reality, the combat capability of the units was lower due to the lack of fuel and the change of airfields. The Bf 109K was the last of the series to see operational duty and the last in the Bf 109 evolutionary line. The K series was a response to the bewildering array of series, models, modification kits and factory conversions for the Bf 109, which made production and maintenance complicated and costly – something Germany could ill-afford late in the war. The RLM ordered Messerschmitt to rationalise production of the Bf 109, consolidating parts, types, and so on, to produce a uniform, standard model with better interchangeability of parts and equipment. At the same time, the existing flaws of the design were to be remedied. Work on the new version began in the spring of 1943, and the prototype was ready by the autumn of that year. Series production started in August 1944 with the K-4 model, due to changes in the design and delays with the new DB 605D powerplant. The K-4 was the only version to be mass-produced. Deliveries of the K-4 began in mid-October 1944. 534 examples had been delivered by the Messerschmitt A.G., Regensburg factory by the end of November 1944, and 856 by the end of the year. Externally the K series could be identified by changes in the locations of the radio equipment hatch, which was moved forward and to a higher position between frames four and five, and the filler point for the fuselage fuel tank, which was moved forward to a location between frames two and three. The rudder was fitted as standard with a Flettner tab and two fixed tabs although some rare examples were not fitted with the fixed tabs. All K-4s were to be fitted with a long retractable tailwheel with two small clamshell doors covering the recess when the tail-wheel was retracted. The wings featured the large rectangular fairings for the large 660x190 mm main wheels. Flettner tabs for the ailerons were also to be fitted to serial production aircraft to reduce control forces, but were extremely rare, with the majority of the K-4s using the same aileron system as the G series. Power was provided in production K-4s by a Daimler-Benz DB 605DB or DC engine (very early K-4s used the earlier DM). A wide-chord, three bladed VDM 9-12159A propeller of 3 m diameter was used, as on the G-6/AS, G-14/AS and G-10. Using MW 50 and maximum boost the Bf 109 K-4 was the fastest 109 of World War II, reaching a maximum speed of 710 km/h (440 mph) at 7,500 m (24,610 ft.) altitude. Without MW 50 and using 1.80 ATA the K-4 reached 670 km/h (416 mph) at 9,000 m (26,528 ft). The Initial Rate of climb was 2,775 ft. (850 m)/min, without MW 50, and 3,563 ft. (1,090 m)/min, using MW 50. The Bf 109 remained comparable to opposing fighters until the end of the war. However, the deteriorating ability of the thousands of novice Luftwaffe pilots by this stage of the war meant the 109's strengths were of little value against the numerous and well-trained Allied fighter pilots. Regensburg delivered a total of 1593 by the end of March 1945, after which production figures are missing. With such a high rate of production, despite continuous heavy fighting, by the end of January 1945, 314 K-4s – about every fourth 109 – were listed on hand with the first line Luftwaffe units. Ultimately it was intended to equip all Bf 109 units with the 109K, which marked the final stage of 109 development before the jet age. The Bf 109 K-4 became the fastest 109 of World War II, reaching a maximum speed of 440 mph at 24,610 ft altitude. Likely half were destroyed ion the ground and of the rest, most were flown by kids as the deteriorating ability of the thousands of novice Luftwaffe pilots by this stage of the war meant the 109’s strengths were of little value against the numerous and well-trained Allied fighter pilots. One of the problems with the 109s was the constant upgrades necessary to try and keep this old aircraft even a bit competitive to the Allied fighters. Every aircraft was precious and had to be kept flying. There were often so many different “M”odels, modifications, upgrades, etc, on a single field the ground crews couldn’t keep up with the staggering array of parts, factory bulletins, improvements, new parts, new maintenance routines, let alone the constant regular day-to-day maintenance to simply keep their crates in the air, let alone keep up with the factory upgrades. And the quality of the field maintenance suffered, not even counting the entire engines that had to be sent back to the factory for the most intricate work, and not even counting the continued deterioration of the German railroad system, likely German’s greatest weapon in WWII, that was being systematically destroyed, and unable to keep up with the constant stream of parts necessary to keep them all flying, competitively or not. I think one of the goals of the K models was for standardisation, to reduce the maintenance overhead related to the myriad of different variants and models still in service that simply drove the field crews crazy, having to deal with the vagaries of each different Mark. It was only partially successful. The Bf 109K was an attempt to rationalize all of that. With a focus on making a high altitude interceptor for opposing the US 8th Air Force, the best features were put together in a single spec. This included a smooth cowling without the characteristic machine gun bulges, an “AS” type engine with water injection capable of nearly 2000 hp, and more aerodynamic air intakes under the wings and fuselage. I *think* the only feature ,unique ,to the Bf 109K was a retractable tail wheel and outer covers for the main landing gear. This all made it the fastest and best climbing variant of the well known fighter. As the “K-4” version it entered service in August of 1944 and continued until March of ’45 when all Bf 109 building came to an end. It never fully replaced the “G” across all manufacturers, except to say it was the last type in production for the last couple weeks. About 1500 of the K-4 were built. A prototype for what would have been the “K-6” flew fall of 1944, but I don’t believe that sub-type ever made it into production. Whatever the Bf 109K’s virtues may have been, it was another of Germany’s too little, too late weapon systems. (Above: A Bf 109G-6 alongside a Bf 109K-4. The bulges forward of the cockpit on the “G” were added when the cowling mounted machine guns were upgraded from 7.92mm to 13mm. On the “K” (and ,some ,“G” models!) the fuselage was flared out to remove the bulges and improve aerodynamics.) The Bf 109K utilized all the best altitude and climb related features of the Bf 109 family. It clearly had the best rate of climb of anything in wide use. For the pilots who flew the Bf 109, it could be a brutal aircraft, with a cramped cockpit and poorly located controls and levers, the pilot could get a serious workout during a dogfight, but don't think this aircraft is not worth the time as a majority of Germany's top aces flew Bf 109s. The Bf 109 K-4 was the final iteration of the aircraft, there really wasn't much more which could have been designed into it to take it any further. In comparison to the early versions which saw combat in the Spanish Civil War, the K-4 was over 300 km/h faster at 2,000 m higher than the Bf 109A. The aircraft morphed from a two-bladed wooden propeller to a three-bladed metal propeller with 20 mm or 30 mm autocannons and 13 mm heavy machine guns over two paltry 7 mm machine guns. The Bf 109 K-4 was meant to dance in the sky with its quick speed, fast rate of climb and excellent energy retention, it can be used to “Boom & Zoom” in the vertical, unlike many other aircraft which require wide swaths of space to make their attack runs and retreats, but again was not the best diver. The manoeuvrability of the aircraft allowed it to make tight turns or quick evasive manoeuvres, especially those which cause a faster and heavier enemy to overshoot and then become the target themselves. But “dogfighting” and heavy manoeuvrability/tight turns was NOT the favoured tactics of the last 4 years of the war, that scrubbed off altitude and speed. The Bf 109 was small and very lightly built, and could easily be shredded by the P-51s six or P-47s eight .50s, let alone the British 20mm Hispano’s, and so for extra pilot protection against mostly the American Browning M2 .50 caliber marine guns, it featured: 60 mm bulletproof glass in front and rear of the pilot Self-sealing fuel tank with 21 mm steel plate behind it, and 4 mm plates surrounding it Pilot's seat has 4 mm steel plates underneath, with 8 mm steel making up the backrest 10 mm steel plates surrounding rear bulletproof glass Willy Messerschmitt's design of the Bf 109 is known for its very lightweight construction, eliminating any unnecessary devices, parts and even structural spars to allow for the fastest that this fighter could be and still be a strong fighter. Part of this challenge was ensuring there was enough protection for the pilot and certain critical components without overburdening the aircraft and make it sluggish with the addition of too much armour. For this aircraft, it makes sense that all of the armour is centred around the pilot as this serves two purposes, aid in the protection of the pilot and two, protecting the fuel tank which the pilot literally sat on top of. The “pilot's office” in the Bf 109K-4 is a conventional aircraft cockpit that is rather cramped and disorganized by late-war standards. (Above: Bf 109 “G”ustuv cockpit: small, cramped, cold, low, bad visibility-horrible.) Cockpit space in World War Two fighters wasn't just a matter of comfort. The pilots needed elbow-room in the cockpit in order to wrestle with the control stick, and put some elbow-grease/torque on it for maximum control. I once got to sit in the cockpit of Doug Champlin’s 109E. Like crouching in an Altoids box: Its tiny, low space made visibility terrible. That so many German aviators did so well in an aircraft clearly inferior to the FW190, is a bit of a mystery to me. One of the most important factors in combat is visibility. The vast majority of pilots in WWII, 85%, never even saw the guy who shot them down. A lot of the game is keeping your eyes peeled, sweeping back and forth for targets, and making sure no one gets the jump on you. A lot of air combat comes down to a few crucial elements: see before being seen, kill before the enemy realises he is dead, do NOT engage in any turning contests, keep your “energy’”(speed/momentum) up, protect your wingman, and, most importantly, come home alive. Not only was the 109′s cockpit low, uncomfortable, and at that time of the BoB, poorly heated at best and claustrophobic, it also confirmed what I had heard from another friend, Jeffrey Quill, the Spitfire’s top test pilot from ’38-on, after taking over from “Mutt” Summers, that the tiny cockpit confined the force that pilots could apply on the controls, with obvious effects on the 109’s flight performance… …RAF testing in '46 revealed that under some conditions, the force its pilots could exert on the 109’s control column was only 40% of what they could equally apply in a Spitfire. In the time when hydraulically-boosted controls weren’t readily available, this was a major deficiency. The Spit’s two-step rudder pedals also permitted the pilot to lift his feet up during high-G maneuvering, delaying the onset of blackout. Unfortunately for the German pilots of the BoB era-109Es didn’t have those pedals. This was a major issue in the Battle of Britain, and an advantage to the Brits… The K’s cockpit was a bit better, but still substandard for the time. Not the best place to fight from as the pilot couldn't get the leverage to really throw the stick around… (Above: ,Engine 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. (Above: An inverted V 12. Why inverted? A couple of reasons, to have the engine sit lower and improve visibility of the already horrible cockpit; the inverted V made the entire frame a bit more aerodynamic/slippery; for ease of maintenance access, [for example, changing the spark plugs on a 109 was a breeze, as the German ground crewman doesn't have to climb on a ladder, but can just stand on the ground;] less exhaust noise from the lower exhaust stacks; and inverted engines have a little bit less wear because upon start up, the cylinders have a bit better lubrication. This is because gravity causes oil to settle in the cylinder walls. “He who is without oil shall cast out the first rod...”-Detonations 5:72.) But while its Daimler-Benz DB601/5 engines inverted V-12s were masterpieces of design and manufacture, they were the *worst* type of engine for actual combat. Like the Allison or Rolls Royce Merlins they were water-cooled and incredibly fragile; Just like your home car: if there was the tiniest leak/hit on any of its vulnerable radiators, (unfortunately exposed in it’s lower wing surfaces, although not quite as bad as the P-51’s huge belly scoop,) water jackets, pumps and hoses, it quickly expelled the coolant, the close tolerances would get *real* close and with a disconcerting CLANG the engine would seize up, turning your beautiful, graceful 109, P-51 or P-40 into a brick. (Give me a Pratt & Whitney R2800 or BMW 801 air-cooled, radial engine that can literally have two complete cylinders shot away and *still* get me home.) (Above: Daimler Benz DB 605- incredibly gorgeous, technically advanced…liquid0-cooled so very vulnerable. One tiny splinter of steel the size of a fingernail clipping, “golden BB”, anywhere in the water-cooling system and it’s ..,Farewell and adieu to you,, ,Spanish Ladies,…”) Engine supply situation was 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. Add to that the Allies 130 octane fuel vs the German’s 95 and there is a huge advantage in speed of 40–60 mph. It is also a testament at this time to German engineering that the DB 605 was even as close to the Merlins and P&W R-2800s as it was, but also remembering it did have 32% more displacement than the Merlin. And then near mid-1944, the Allies fuel octane jumped up to and became standard at 150, another significant advantage. Was this significant? You could say…! A P-51 that had run at 67 inches manifold pressure at WEP on 130 octane could now run at 75 inches on 150 octane. (A note on War Emergency Power: its a throttle setting. At full throttle the P-51, for instance is running at 61 inches of manifold pressure, but if the pilot needs an extra burst of power…Wham!) A big part of the Allies’ Spitfire’s and P-51′s Merlins superior performance with smaller displacement was the far higher octane fuel that was coming from America, just in time for the Battle of Britain, that allowed increased manifold pressures and significantly more power. A must-read is about Jimmy Doolittle, Eugene Houdry and Alex Golden Oblad, two unsung heroes of the battle of Britain and WWII itself, and their work on a chemical catalyst process for the Sun Oil Company, now Sunoco, which converted almost useless crude oil/sludge into 100-octane fuel that America gave England to replace the standard European 87 octane fuel just before the Battle of Britain and helped increased the Spitfire's speed by 25 mph at sea level by 34 mph at 10,000 feet, a not inconsiderable advantage against the Bf 109s. (In the early 1930s Eugene Houdry collaborated with two American oil companies, Socony Vacuum and Sun Oil, (later Sunoco,) to build pilot plants. Oil companies that did not want to resort to the new additive tetraethyl lead were eagerly looking for other means to increase octane levels in gasoline. In 1937 Sun Oil opened a full-scale “Houdry unit” at its refinery in Marcus Hook, Pennsylvania, to produce high-octane Nu-Blue Sunoco gasoline. By 1942, 14 Houdry fixed-bed catalytic units were bearing the unanticipated burden of producing high-octane aviation gasoline for the armed forces.) …And here about octane numbers/ratings: The BF 109 was an outstanding aircraft but starting with the battles against the Spitfires, and as the war progressed, it suffered one great, almost insurmountable, weakness compared to the British and American aircraft it battled against: it was significantly slower. The DB 601, esp., was just never able to run at the higher horsepower levels that the Allies could. And there are many reasons for this: from supercharger gearing to intake manifold pressures to octane ratings to levels of tuning and too many more to get into on this broad answer. Most of its combat advantages and subtleties that made it, as I said, agile and deadly, were lost to the new batch of poorly trained pilots that were being fielded and from the drastic change in combat tactics, from the twisting, tight-turning dogfights over The Channel to the “zoom and boom,” ambush-dive, roll, ”energy” tactics of the later war that did not favour the poorly diving/rolling 109. Mr. Rall used these tactics well as he was an expert, but the younger, greener German pilots, were not taught these subtleties, tricks and tactics and from mid 1944 on, the Bf 109’s in any configuration or variant, increasingly became fast moving “fawns” to the Spitfires, P-51s and P-47 “wolves.” The final “K” 109 models were, as a testament to some brilliant German engineering, for a change, much faster, but still came too late in the game and again were in the hands of third-rate pilots/boys. So much of the German development “IQ Points” was, thankfully, geared/wasted around making decent Horse Power off the substandard and low octane synthetic fuel they were stuck with for much of the war. 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. (Above: The large advantage of the Daimler-Benz 605 engine is its direct fuel injection. While most Allied aircraft used 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.) MW-50 Water-Methanol Injection MW-50 (MethanolWasser 50) is a 50-50 mixture of methanol and water sprayed into the Bf 109K-4's supercharger, allowing the use of increased boost pressures. Many Bf 109 variants use some sort of boost. The G-6 was the first variant designed for a new field modification kit or “Rustsatz” model that allowed a large number of various standard kits to be quickly installed in the field, as well as a number of “Umrutsatz,” or factory kits that could be installed in the factory. The U2 kit provided for a 118-liter tank behind the cockpit used for the GM 1 nitrous oxide injection system, while the U3 kit used a tank for the MW 50 water-methanol mix: (Above: At sea level, the engine runs at over 1800 hp with MW-50 enabled, compared to 1430 hp with the MW-50 off. The boost provided by the MW-50 begins to decrease in power at altitudes above 6,000 meters.) Fuel System The Bf 109K, as most Bf 109 variants, uses a single main 250-liter L-shaped fuel tank located partly under the cockpit floor and partly behind the rear cockpit bulkhead. The Bf 109K-4 can also carry an external drop tank under the fuselage with the capacity of 300 liters. The fuel system operates on a simple principle. When more than one fuel tank is used, all tanks are daisy-chained and fed into one another. A Fuel Selector lever located on the left side of the Front Dash allows the pilot to manage the system. Two fuel pumps are provided, P1 and P2. P1 draws fuel from the rear section of the tank, while P2 draws fuel from the front of the L-shaped tank. A Fuel Cock lever located below the throttle quadrant is used to switch between the fuel pumps, with the options of ZU (both off), P1 (P1 pump), P2 (P2 pump), and P1+P2 (both). The engine always draws fuel from the main tank. When drop tanks are used, their fuel pump feeds the main tank. The Fuel Contents Gauge will continue to display full for as long as the drop tanks continue to feed the main tank. Once the drop tank is emptied, the fuel quantity in the main tank begins to decrease. When drop tanks are used, the Fuel Selector Switch should be set to Hinten. The Fuel Contents Gauge will continue to display full for as long as the drop tanks continue to feed the rear and in turn the forward tanks. Once the drop tanks are emptied, the fuel quantity in the rear tank begins to decrease. Hydraulic System The hydraulic system in the Bf 109 is used to operate the landing gear and the wheel brakes. The landing gear is normally raised and lowered hydraulically. There is also an auxiliary manual system for operating the gear. The Bf 109K-4 also 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. Oil System A circular oil tank is located in the nose. As no armor protection is provided for the oil system, the oil tank and the oil cooler are some of the aircraft's most vulnerable spots. (Above: Turquoise unarmored oil tank, lines, with oil radiator underneath.) The oil system is used for the following: Landing Gear Operation; Oil Radiator Flap; Radiator Flap. Below: Oil system: Coolant System The Bf 109 K-4 used two matching radiators partially recessed in the wings for cooling. First introduced during a radical redesign of the F for “Friedrich” variant, the system used a system of interconnected flaps to efficiently regulate cooling while providing the least possible drag. The flaps are controlled automatically by a thermostat that works to provide maximum cooling by moving the flaps in unison as needed. The automatic system can be somewhat sluggish, especially on the ground. Common pilot tactic is to nudge the throttle slightly on take-off to reach the proper temperature limit, causing the automatic cooler flaps to open or close as needed. Manual override for the system is also provided. It should be used in the case of emergency; during normal operation it is highly recommended to use the automatic system. This liquid-coolant system was totally unarmored and, like all vulnerable liquid-cooled engines, was the #1 “Achilles’ Heel” of the Bf 109. “As far as the 109 versus 190 argument, the 109 had the liquid-cooled engine whereas the 190 had an air-cooled radial engine, much like ours. One hit in the cooling system of a Messerschmitt and he was going down...”-Robert S. Johnson, 56th FG, “Zemke’s Wolfpack,” #2 US Ace in ETO, P-47s, 27 “kills.” Armament It had two 13mm (.51 in.) MG 131s on the cowling/nose w/300 rds per gun, and one 30mm Mk 108 in the nose firing through the prop. (Above: Mk 108 30mm cannon.) (Above: A1-.50/.30—C- 13mm MG 131 — G-30mm Mk. 108 (designed to destroy bombers and effective against light amour.) (About that 30mm Mk 108 in the nose with 65 rds: I am of two minds about that 30mm: I love the innovation of the inverted V engine, its tremendous power, and utilising the cannon firing through the prop hub, but the 30mm was of such (relatively) low velocity of only ,540 m/s,, compared to 850 m/s for the MG 151/20. I knew Gunther Rall well in his last years and he talked about how much he relied on his cannon when he ambushed so many enemy aircraft, waiting till they filled his windscreen then giving them all his guns, esp. his nose cannon so he should know. But when your different guns fired their ammo at such different velocities and as the marksmanship felll so drastically as their pilot quality decreased it must have made it tough. Im also a bit leery of the fact that the MK 108 Motorkanone jammed frequently. My fav aircraft of WWII and my opinion the greatest fighter of all the was the P-47 and its eight .50s and it had variable heated gun and ammo bays that functioned perfectly even at the coldest high altitude, but the Bf 109s gun bays weren't heated, and the ammo/links sometimes froze up a bit and jammed. But I guess I’d go for the 30mm’s hitting power in the long run.) It was devastating when it hit but required a bit of tricky shooting to utilise that power esp. coordinated with its higher velocity auxiliary weapons. Armament of the K-4 consists of a 30 mm (1.18 in) MK 108 engine-mounted cannon (Motorkanone) with 65 rounds, and two 13 mm (.51 in) MG 131s in the nose with 300 rounds per gun. Additional Rustsatze, or equipment kits, such as a 300 L (80 US gal) drop tank (R III), bombs up to the size of 500 kg/1,100 lb (R I). An important fact that must be mentioned when discussing the armament is the quality of German ammunition. Largely ahead of its time and superior to comparable Allied examples, German cannon shells use centrifugal fusing in shells which contain several times more explosive than Allied shells due to the use of thinner walls. High-quality explosives used in the shells also provide considerably more punch than comparable Allied examples. The Bf 109 uses electrically operated guns, as do most other German aircraft of WWII. This makes weapon selection easier than on Allied aircraft, and also enables a unique system of ammunition counters that takes all guesswork out of aerial gunnery. As was typical of Bf 109s was having a Motorkanone mounted to shoot through the propeller hub. The 30 mm Mk 108 autocannon tended to jam during combat. This was a problem with the gun feed but also exacerbated by flying at very high/cold altitudes where the unheated gun bays could be locked by freezing condensation. The 30mm round is a slow but deadly round and when fired at close range it can have devastating results on its target. A large disadvantage due to its size and weight only carries 65 rounds made it necessary for the pilot to exercise disciplinary control and only fire when they are sure the rounds will hit. The 30mm MK 108 is a double-edged sword: Nicknamed by the allies for its characteristic sound, the ,Jackhammer, lives true to its name. Slow but powerful. Its ,main purpose,: Demolition of heavy objects, such as the B-17G Flying Fortress. However, its ,common purpose ,remained to hunt fighter planes. Often the stronger Fw190s with their far more cannons would go after the bombers while the Bf 109s would go after the fighter escorts. The cannon's rate of fire is surprisingly high for its caliber - 660 rpm - meaning that, while deflection shots can be made, absolute trigger discipline must be maintained - the 65 rounds given to you will last you less than ,6 seconds, of continuous fire. Furthermore, the minengeschoß-shells are slow- very slow. One had to be either become very good at leading the shells or else, preferably, close the distance. Kills with the 30mm were generally done from 300 meters away, if not closer, ala Gunther Rall/Erich Hartmann. The two additional 13mm machine guns were most often fired alone. The MG 131 features HE shells as the ,Tracer belt,. One technique the more experriced “experten” would use is “prop pitch technique.” Most of the later 109s had this featured so did the 109 K-4. The prop pitch technique is using Manual Engine Control to set the prop pitch to 100% but throttle to 0%. This would make the prop a giant air brake and was very helpful in forcing overshoots of enemy aircraft. It can also be very helpful in diving when they would get dangerously close to their maximum speed. Cockpit equipment for the armament includes the Revi 16B gunsight… …as well as the SZKK 3 ammunition counters…While provisions were made for the more advanced lead-computing EZ 42 gunsight, late-war production difficulties meant that production K-4s shipped with the simpler Revi 16B. The SZKK 3 ammunition counter shows the ammo stores for each of the two MG 131. The left-hand vertical bank in the SZKK show the state of the left MG 131, and the right-hand indicator the right MG 131. The ammo counters are not directly linked to the ammo stores. Instead, they are reset to full (top) position when the guns are loaded on the ground, and then each mechanical indicator bar is lowered by one notch whenever a weapon is fired. Notches provided to the side of each indicator show the amount of rounds in the ammo store for each weapon. White bar portion signifies ammunition in the stores; black bar portion signifies expended ammunition. The Bf 109K-4 is also equipped with the Revi 16B reflex gunsight. It was slated to be replaced by the EZ 42 Gyro gunsight, but this never materialized due to late-war supply troubles. The Revi 16B is a standard reflector sight used on many German aircraft. While attempts to introduce lead-computing sights began rather early in the war, the RLM continued to prefer simpler Reflex Sights (Reflexvisier or Revi for short) well into 1944. All reflex sights used by all nations use the same basic principle and project a reticule image onto a sight glass into infinity. Reflector sights such as the Revi 16B do not compute lead and simply provide a dead aiming point relative to the aircraft gun line. When using a reflex sight in combat, the pilot has to make manual adjustments to account for target lead, G load, distance to target, and other parameters required for accurate aerial gunnery. The K’s #1 opponent was the P-51 with the Packard-built Rolls Royce Merlin engine. The Merlin 61 was an incredibly powerful engine for its size: The Bf 109’s Daimler Benz DB 605 engine was significantly bigger in displacement (32%) than the Rolls Royce Packard-built Merlin, but the P-51s had two superchargers attached: one feeding the engine and one feeding the other supercharger… And there were two main versions of the Packard Merlin 1650: the -7 version was geared so its supercharger drive speed would be optimal at War Emergency Power (WEP) with 130 octane fuel at 6200 feet with the supercharger in low speed and at 19,300 feet in high speed. (The -7 is the Merlin typically quoted for HP numbers.) Making 1,720 HP. But this version was not optimal for escorting high altitude bombers at 25,000 feet so another Packard Merlin version, the -3 which had different supercharger drive ratios which changed the shaft speed, was introduced. The -3 engine actually has less power overall but gives it more power at 17,000 feet at low speed and 28,800 feet at high speed. Making 1,595 HP. Many P-51’s were retrofitted with the -3 supercharger kits giving less overall HP but more where they needed it at high altitudes. And as the Bf 109 G’s start running out of steam/manifold pressure at only 18,800 feet that was a huge advantage for the P-51 and P-47s. The -3 has 1595 HP on 120 octane fuel vs 1720 for the -7 but its a question of *where* that power is *available* at 25,000 feet and higher where the bombers were flying. (Above: Merlin engine.) The main German trick for fighting the P-51/P-47s was to fight them at less than 20,000 feet, and the German pilots were taught to bring the fight down to lower levels if possible where it was more agile…but the P-51 and esp the P-47 were far better divers, and the P-47 was also a significantly better roller, so that was tricky, also as the German pilots were steadily getting greener and the U.S. pilots were getting better. But the K was able to fight at higher altitudes and eliminated some of these Allied advantages. About the significant speed deficiency of the 109 to esp. P-47s and P-51s, the Germans being more and more on the defensive as the war progressed, for example, as the German ground crew’s ability to specifically fine-tune and optimise the Bf 109’s manifold pressures to a specific altitude for maximum power was lost to the “REactive/defensive” position vs the allied “ACTion”/offensive moves, where the British and American ground crews were able to fine-tune their Spitfires, P-51s and P-47s for maximum power knowing at approximately what altitude their pilots would be flying their missions at. The 100/130 av-gas allowed the Allied aircraft to run “hotter” manifold pressures, and have considerable power/speed advantages… But the German quite early came up with a methanol-water injection system, using a 22.5 gallon tank (85 liter) behind the cockpit and running a line to to the engine, ridiculously simple, and with it the Bf 109 G14 model could run 51 inches of manifold pressure making 1775 Hp, up 300 hp of the older G6 Models, running 42.5 inches of manifold pressure, giving the G14 a top speed of 413 mph, (and a high altitude version the G14 As, which had it’s supercharger optimised for fighting up high, with a top speed of 422 mph.) It could be used for 30 minutes total, only ten minutes at a time, with a 3 minute cool-down period between each. Again not as fast as the P-51Ds or P-47Ds but at least the Mustangs and Thunderbolts could not so easily escape the fight at will against the slower G4s. That the K model was so fast was a true burst of engineering brilliance from the German designers/engineers, esp with the MW 50 methanol-water injection that was incredibly simple, but wasted on the green pilots. Production claim figures vary widely but likely half were destroyed before they even flew, and the K4 was the best of them all, 2000 hp, 452 mph, the only one that was a bit faster than a P-51D, (425 - 447 mph) and slower than the P-47 M, (475–500 mph) but in the hands of a rare surviving “experten,” was very dangerous. But it was, of course, pretty hopeless for the Germans by that time. Here’s a drawing I did of Erich Hartmann and the Bf 109 K4 he MIGHT have flown towards the end: Part of the increased speed was the very limited amounts of the new and in limited-amounts, German C3 fuel with 100 octane rating (vs their usual B4 synthetic fuel with 87 octane, which, BTW, with the MW system on the G14s, raise the octane of the 87 fuel to 100, just by itself from the anti-knock function of the water.) But here's the thing, the Germans *had* the technology for the MW 50 system back in 1940, but never utilised it! Imagine if they had used it on the old E models in the Battle of Britain in 1940 (and the Fw 190s set up in 1941), increasing the 109’s HP by an extra 200–300, it could have made things potentially very tough for the British…until you remember the never-ending problem of the Bf 109’s low fuel capacity and its inability to carry much external weight. Another big issue was that the P-51′s Merlin had an after-cooler, a liquid-to-air heat exchanger that cooled the hot air coming out of the superchargers, similar to modern liquid-to-air intercoolers found on high performance cars today. The after-cooler adds power in two ways: first it increases the density of the charge by cooling it, and second, it reduces the tendency to knock allowing greater manifold pressure. So the 109 did NOT have dual stage superchargers, the first feeding the engine and the second feeding the first supercharger. And it did NOT have an after-cooler. (Here’s where Willy Messerschmidt additionally screwed up on the initial design: by designing it as such a little “racehorse,” the actual physical size of the 109 was so small, the fuselage was so tight, it had very little room for the modifications it needed to stay competitive from 1936 -1945. Folks not in the know deride the huge P-47 for its huge size not understanding the incredible advantages of the bigger fighter beyond the fact that enemy projectiles had to travel through significant amounts of steel to hit anything vital, and the room to continue to upgrade it as the war and technology progresses.) Add to that again, the Allies 130 octane fuel vs the German’s 95 and there is a huge advantage in speed of 40–60 mph. It is also a testament at this time to German engineering that the DB 605 was even as close to the Merlin as it was, but also remembering it did have 32% more displacement. And then near mid-1944, the Allies fuel octane jumped up to and became standard at 150, another significant advantage. Was this significant? A P-51 that had run at 67 inches manifold pressure at WEP on 130 octane could now run at 75 inches on 150 octane. (A note on War Emergency Power: its a throttle setting. At full throttle the P-51, for instance is running at 61 inches of manifold pressure, but if the pilot needs an extra burst of power… …he pushes the throttle forward HARD, it will break a “stop wire” and go farther forward and deliver either 67 or 75 inches of manifold pressure depending on which setup/fuel which gave the pilot 5 minutes at WEP. After debriefing each pilot had to log the minutes under WEP and after 50 hours of WEP the engine was removed, and disassembled looking for signs of extra wear. (The P-47′s incredibly tough, and lower tolerance air-cooled R2800 engines could run much longer and harder on WEP and with significantly less wear.) Also WEP did nothing for Allied fighters below 5000 feet. At higher altitude, however the increase in HP was between 100–150 HP. Additionally the P-51’s Merlin also could rev higher that the 109s DB 605: 3000 rpm vs 2700 rpm. The Germans kept trying to replace the 109 but without success; the hoped -for replacement 209s/309s were expensive failures, additionally hurt by Hitler’s personal affection/blindness for Willy Messerschmidt, himself. Why they didn't gear their entire production capabilities towards the far superior, newer and more upgradable Fw190 series that was NOT at the end of its development cycle, then the tired-out 109 is testimony more to Willy Messerschmidt’s good status with Hitler than the aircraft’s basic abilities, now stale, and their poor long-range strategic manufacturing planning, (Below: GREAT Daimler Benz DB 605 engine sound as it passes!! Bf 109K-4 cockpit layout: 1 Horizontal Stab. Trim; 2 Flap Handwheel; 3 Cabin Vents; 4 Fuel Selector Handle; 5 Tail Wheel Lock; 6 Glove Heater Plug; 7 Stabilizer Trim Indicator; 8 Engine Primer Hand Pump; 9 Bomb or Drop Tank jettison; 10 Prop Pitch Auto/Man. Switch; 11 Man. Coolant Valve Controls *; 12 Momentary Limit Switch; 13 Quick-Stop Handle; 14 Fuel Selector & Cutoff; 15 Winter Start Handle; 16 Throttle with Thumb Switch for Prop Pitch Control; 17 Motor Generator for Artificial Horizon; 18 UV Cabin Lights; 19 Canopy jettison Handle; 20 Starter Handle; 21 Landing Gear Push Buttons; 22 Selector Switch for 21 cm Rockets or MK 108 ; 23 Landing Gear Indicators; 24 Magneto Switch; 25 Switch for MW Installation; 2 6 Jettison Switch for 21 cm Rocket Tubes **; 27 Windscreen Cleaning Valve; 28 Main Elect. Circuit Breaker; 29 Master Weapon Switch; 30 Ammunition Counters & Indicators; 31 Armor Glass Windscreen; 32 Gun Sight Revi 16B; 33 Gun Sight Mount; 34 Pessure Gauge for MW Installation; 35 Airspeed Indicator; 36 Artificial Horizon; 37 Vertical Speed Indicator; 38 Altimeter; 39 Repeater Compass; 40 AFN2 Instrument Flight Indicator; 41 Instrument Flight Panel; 42 Fuel & Oil Pressure Gauge; 43 Coolant Temperature Gauge; 44 Tachometer; 45 Flare Gun Port; 46 Oil Temperature Gauge; 47 Prop Pitch Indicator; 48 Manifold Pressure Gauge; 49 Emergency Land. Gear Release; 50 Low Fuel Warning Light; 51 ZSK 244A Bomb Arming Panel; 52 Cover for MK 108; 53 Control Column Grip; 54 Charging Button For MK 108; 55 B2 Button for Bomb Release; 56 Bl Button for MK 108 or Rockets; 57 A Button for MG 131; 58 Radiator Flap Control ; 59 Fuel jettison Handle; 60 Circuit Breaker Panel; 61 Compass Deviation Card; 62 Oxygen Monitor; 63 Oxygen Pressure Gauge; 64 Drop Tank Fuel Transfer Sight Glass; 65 Oxygen Regulator; 66 Main Valve for Oxygen System; 67 Control for FuG 16ZY Radio; 68 Frequency Selector for FuG 16ZY Radio; 69 Headphone Volume Control; 70 Control for FuG 25a (IFF) Radio; 71 Headphone Jack; 72 Oxygen Mask Hose. Thanks for the time!