World War II was the first conflict to employ the use of night fighter operations and this led to a number of types of aircraft being used, different radar types being used and different tactics being used as the war progressed. Very early in the war when RAF Bomber Command chose to bomb civilian targets the Luftwaffe had one goal which was to "search and destroy".
The Luftwaffe then began to follow two night fighting tactics..... a) Dunkel Nachtjagd was the term for dark night fighting and this was where the night fighters were guided by a radio beacon which led them to their targets with the aide of Freya stations. These were a rudimentary early warning radar station. When a fighter arrived in the British bomber stream it needed a visual identification so it could target and then destroy the bomber. In 1940 these Freya Stations ran from the Danish to the Swiss frontier. The first Luftwaffe successes happened in September of 1940. b) Helle Nachtjagd was the term used for clear or illuminated night fighting and was established to improve upon the Dunkel Nachtjagd tactics. Now in addition to the radio beam and the early warning radar the night fighters were now going to be aided by ground searchlights which were also controlled by radar. This would illuminate the bombers and blind the crew. The searchlight batteries ran from Reims in France to Flensburg in Germany. This area was made up of 18 zones and 28 miles x 22 miles. RAF Bomber Command realized quickly that all they had to do was fly around the illuminated zones. Germany knew new tactics would have to be developed using radar.
German flak was another issue as it was only placed in certain area near important Allied targets. The flak worked with radar, an optical rangefinder and searchlights. Each flak battery had 4-8 88mm, 105mm or 128 mm guns. Their shells had timers so they would explode close to the bomber stream. The 88s and 105 mm had a range of 29,167' while the 128 mm had a range of 35,850'. By 1945 the Germans in order to bring down a bomber would have to fire 10,000 shells In May of 1940 it was proposed that the Bf 110 by used as the Luftwaffe night fighters. With RAF Bomber Command increasing their attacks it should the Luftwaffe was not able to stop and destroy the bombers that were pounding German industries. On July 20, 1940 it was ordered that a night fighter force be set up. The new unit was comprised of I.NJG 1 with the Messerschmitt Bf 110; II. NJG 1 with the Junkers 88 C-2 and III.NJG 1 with the Messerschmitt Bf109. This force was called Nachtjagdeschwader 1 with Headquarters in Brussels while the nightfighter Headquarters was in Arnhem in the Netherlands. In late 1940 , the Germans were working on their own radar and it took shape in the FuG 202 Lichtenstein BC and this would become the standard Luftwaffe radar for a few years. Throughout the Reich the air defences were improving and the Luftwaffe developed a new tactic......
Fernnachtjagd which was a tactic against long range missions by the night fighters over enemy controlled areas and to attack the bombers on their return leg from the target and when they are near their home airfields. The bombers were vulnerable taking off in the dark, forming up with the bomber stream and when they would try to land at their home field with their navigation lights on. II. NJG 1 was renamed I.NJG 2 flying the Junkers 88s and based at Gilze-Rijen in the Netherlands.
Following 1941 , the Helle Nachtjagd was slowly phased out in favour of "combined" fighting zones, with both Dunkel Nachtjagd and Helle Nachtjagd continued but improvements in night fighting were being achieved. The Henaja searchlight batteries received the new Wurzburg radar which could direct a searchlight beam onto a bomber. With more experience the German night fighter system began to be more effective in the spring of 1942. Then, Hitler ordered the Henaja searchlight system belt be withdrawn gradually from March to July and placed aroubnd the main defences of targeted cities. Now the Henaja system had to change to a "combined" fighting zone called Konaja and this tried to combine flak, the searchlights and the night fighters over target cities. The Konaja was to fire less than 13,100' and the fighters were ordered to fly above this height. The next innovation was the Himmelbelt (Four Post Bed) which was a line of radar stations 18 miles apart with each having flak guns and searchlights. Each station had a Freya radars with a 100 mile range and 2 Wurzburg radars with a range of 40 miles. The Freya located the bombers and the Wurzburgs would tracked a night fighter and guided it to the target. The fighters were assigned to a zone and flew in that area until ground control contacted them and would guide them to their target. The Himmelbelt was only able to guide one fighter in a zone to a target. They were able to create a line from Denmark to France. During 1942 two new Luftwaffe units came on board which were NJG.4 and NJG.5 and more aircraft were available to attack the bombers. In addition, the night fighters were now beginning to use the FuG 202 Lichtenstein B/C A1 radar antennas on the fighters. Still the chance of success was low because up until now RAF Bomber Command was sending small bomber groups to German targets but even so the RAF losses were 7%. From February 1942 the RAF changed tactics and began sending massive formations and they were concentrated in a thin line of the Luftwaffe defences in the shortest period of time and this causes the German system to collapse. The more RAF bombers that were put in the air lowered their losses. Now the RAF losses were 3.9%. From March of 1942 the Raf began to use electronic devices like the GEE which was a navigational aid that could range out over the Ruhr and guided the bomber and showed where to drop the bombs. Another RAF aid was H2S which was a downward looking radar that could identify cities shown in the shape and could bomb blindly. By 1943 the Luftwaffe night fighter system was well established with 1,000 aircraft but when the RAF introduced the "window" it almost paralyzed the Luftwaffe night fighter operations. The Germans called it Duppeln. Window was a aluminum foil that was one half-wavelength long at it created a mess on the German screens and jamming the German radar and this made the searchlights ineffective. The Dunaja system became ineffective. From July 1943 the window was used nightly and the Luftwaffe night fighter system almost came to a halt. However, the Luftwaffe had developed the "Wilde Sau" system. Single seat fighters began to take advantage of the flak batteries near the searchlight batteries. The shells would explode below where the fighters were preying and the bombers were now illuminated from the searchlights making them easier prey.
At the beginning of August 1943 the Luftwaffe night fighter organization was made up by 5 Jagddivisionen of the XII Fliegrtkorps and were
a) Jagddivision I, II, III and IV/.NJG 1 b) Jaggdivision I, II, III and IV/ NJG 3 and Nachjagdkommando 190 c) Jagddivision II/NJG 4 d) Jagddivision I & III/NJG 4, I & II/NJG 2, I & III/NJG 5 e) Jagddivision I/NJG 6
The "Battle of Berlin" began in the middle of November 1943 and RAF Bomber Command was going to take advantage of the "window" effect on the German night fighters. The FEE and Oboe devices worked well against the Germans, but the H2S did not. The missions against Berlin numbered 35 and the RAF losses were 10% and this was double of what was acceptable. To that end the Battle of Berlin was a German victory. At the end of 1943 the Luftwaffe "Wilde Sau" system along with the Himmelbett system worked together to try and stop the RAF raids and now another war between the RAF and Luftwaffe and this war was across the radio spectrum and still despite all the Luftwaffe efforts and their improved training of the night fighter pilots and crews the RAF bomber streams continued flying and bombing the German cities. RAF Bomber Command 100 Group was formed in late 1943 and used electronic countermeasures against the German radar systems and at this time the Mosquito began their raiding missions over the Reich. The German night fighters were no match for the superior Mosquito and began to use the Ju 88 as the backbone of the Luftwaffe night fighter force. The Mosquito flew with the bomber stream jamming the enemy communications and navigational aids. In addition, now the RAF began to use Mosquitos as "pathfinders" which were aircraft that flew ahead of the bomber stream and marked the target with flares. The Mosquito night fighter, bomber and reconnaissance versions was a constant problem for the Luftwaffe through 1944-45. The Mosquito even set up ambushes to German night fighter beacons and airfields. The only Luftwaffe aircraft that could hold its own against the Mosquito was the Bf 109 G-5 and were deployed in the JG 300 and JG 302 and had mounted a DB 605AS turbocharged engine. They also reduced weight and armament and flew with one cannon and two machine guns in order to catch the Mosquito.
Luftwaffe Night Fighters
RAF Bomber Command flew over the coast of the Netherlands on their way to targets such as Cologne, Frankfurt and Nuremburg and on the return leg would fly over Strasbourg, Paris and on to England. Before night fighters were in danger from flak and searchlights. The night fighter of the Luftwaffe put a whole new spin into a bombing mission.
Messerschmitt Bf 110G was very successful. The top speed was 342 mph and a maximum ceiling of 26,000' it could easily get itself into the bomber stream. I Armament was 2x20mm cannons along with a 7.9 mm machine gun.
Junkers Ju88G6 and this aircraft was equipped with the upward facing "Schrage Musik" which was a 2x20 mm cannon mounted in the central fuselage. It had a maximum speed of 311 mph and had a maximum ceiling of 32,500' . In addition to the upward firing cannon it also had 3x20 mm cannons a nd 3x7.9 mm machine gun. Dornier Do-217J was an aircraft with a top speed of 320 mph with a maximum ceiling of 31,170'. It was more heavily armed that the Bf 110G / Ju88G6 it had 4x20 mm cannons, 4x7.9 mm machine guns plus 1 remote controlled dorsal turret machine gun of 13 mm calibre. Heinkel "Owl" began flying in 1942 but only 268 were built because of the targeting RAF Bomber Command raids. It had a top speed of 416 mph with a maximum ceiling of 41,500'. It was armed with 2x30 mm cannons, 2x20 mm cannons and 2x30 mm "Schrage Musik" cannons.