Schräge Musik
Encyclopedia
Schräge Musik, derived from the German colloquialism
Colloquialism
A colloquialism is a word or phrase that is common in everyday, unconstrained conversation rather than in formal speech, academic writing, or paralinguistics. Dictionaries often display colloquial words and phrases with the abbreviation colloq. as an identifier...

 for "Jazz
Jazz
Jazz is a musical style that originated at the beginning of the 20th century in African American communities in the Southern United States. It was born out of a mix of African and European music traditions. From its early development until the present, jazz has incorporated music from 19th and 20th...

 Music" (the German word "schräg" literally means "slanted" or "oblique") was the name given to installations of upward-firing autocannon
Autocannon
An autocannon or automatic cannon is a rapid-fire projectile weapon firing a shell as opposed to the bullet fired by a machine gun. Autocannons often have a larger caliber than a machine gun . Usually, autocannons are smaller than a field gun or other artillery, and are mechanically loaded for a...

 mounted in night fighter
Night fighter
A night fighter is a fighter aircraft adapted for use at night or in other times of bad visibility...

s by the Luftwaffe
Luftwaffe
Luftwaffe is a generic German term for an air force. It is also the official name for two of the four historic German air forces, the Wehrmacht air arm founded in 1935 and disbanded in 1946; and the current Bundeswehr air arm founded in 1956....

and Imperial Japanese Navy Air Service
Imperial Japanese Navy Air Service
The Imperial Japanese Navy Air Service was the air arm of the Imperial Japanese Navy during World War II, the organization was responsible for the operation of naval aircraft and the conduct of aerial warfare in the Pacific War.It was controlled by the Navy Staff of the Imperial Japanese Navy and...

 during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, with the first victories for each occurring in May 1943. This innovation allowed the night fighters to approach and attack British bomber
Bomber
A bomber is a military aircraft designed to attack ground and sea targets, by dropping bombs on them, or – in recent years – by launching cruise missiles at them.-Classifications of bombers:...

s from below, where they would be outside the bomber crew's field of view.
Few bombers of that era carried defensive guns in the ventral position. The ventral turret fitted to some early Avro Lancaster
Avro Lancaster
The Avro Lancaster is a British four-engined Second World War heavy bomber made initially by Avro for the Royal Air Force . It first saw active service in 1942, and together with the Handley Page Halifax it was one of the main heavy bombers of the RAF, the RCAF, and squadrons from other...

s was sighted by periscope from within the fuselage, and proved of little use.
An attack by a Schräge Musik-equipped fighter was typically a complete surprise to the bomber crew, who would only realize that a fighter was close by when they came under fire. Particularly in the initial stage of operational use until early 1944, the sudden fire from below was often attributed to ground fire rather than a fighter.

World War I

During World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

, forward firing Lewis Gun
Lewis Gun
The Lewis Gun is a World War I–era light machine gun of American design that was perfected and widely used by the British Empire. It was first used in combat in World War I, and continued in service with a number of armed forces through to the end of the Korean War...

s were frequently mounted on a Foster mounting
Foster mounting
In early 1916 Sergeant Foster of No. 11 Squadron RFC devised a sliding rail mounting for the upper wing Lewis Gun on a Nieuport 11. It enabled the gun to be pulled down so that its breech was conveniently in front of the pilot, making it much easier to change ammunition drums or to clear stoppages...

 on the top wing of a biplane to fire over the revolving propeller, due to the difficulty of synchronizing this type of weapon to fire through the propeller arc. Since the gun had to be tilted-back to change ammunition drums, the gun could also be fired upwards at an angle. The guns of the Nieuport 11
Nieuport 11
|-See also:-References:NotesBibliography* Angelucci, Enzio, ed. The Rand McNally Encyclopedia of Military Aircraft. New York: The Military Press, 1983. ISBN 0-517-41021-4....

 and Nieuport 17
Nieuport 17
|-Specifications :-See also:-Bibliography:* Bruce, Jack. "Those Classic Nieuports". Air Enthusiast Quarterly. Number Two, 1976. Bromley, UK:Pilot Press. pp. 137–153....

 fighters, especially in British service, and the Royal Aircraft Factory S.E.5
Royal Aircraft Factory S.E.5
The Royal Aircraft Factory S.E.5 was a British biplane fighter aircraft of the First World War. Although the first examples reached the Western Front before the Sopwith Camel and it had a much better overall performance, problems with its Hispano-Suiza engine, particularly the geared-output H-S...

a were often used in this way, to attack enemy bomber or reconnaissance aircraft from the "blind spot" below the tail. The British ace
Flying ace
A flying ace or fighter ace is a military aviator credited with shooting down several enemy aircraft during aerial combat. The actual number of aerial victories required to officially qualify as an "ace" has varied, but is usually considered to be five or more...

 Albert Ball
Albert Ball
Albert Ball VC, DSO & Two Bars, MC was an English fighter pilot of the First World War and a recipient of the Victoria Cross, the highest decoration for gallantry "in the face of the enemy" that can be awarded to members of the British or Commonwealth armed forces...

, in particular, was a great exponent of this technique and had developed the tactic of getting under and just behind his adversary, and with his upper-wing mounted machine gun in his SE.5, pulled down on its ratchet tracks at an angle of 45°, was able to shoot down the enemy from below. Ball also mounted another machine gun in the bottom of the cockpit to fire downward. Along with many other RFC and French combat aircraft, the Nieuport 17 utilized a unique arrangement of Le Prieur rocket
Le Prieur rocket
Le Prieur rockets were a type of incendiary air-to-air rockets used in World War I against observation balloons and airships. They were invented by the French Lieutenant Yves Le Prieur and were first used in the Battle of Verdun on 1916...

s mounted obliquely to the interplane strut
Interplane strut
An interplane strut is an aircraft airframe component designed to transmit lift and landing loads between wing panels on biplanes and other aircraft with multi-wing designs. They also maintain the correct angle of incidence for the connected wing panels and are often braced with wires...

s, and designed for "stand off" balloon attacks.
The concept of off-set or oblique mounted weaponry in night fighting was first used by Royal Aircraft Factory B.E.2c night fighters to attack airship
Airship
An airship or dirigible is a type of aerostat or "lighter-than-air aircraft" that can be steered and propelled through the air using rudders and propellers or other thrust mechanisms...

s from below. RFC/RAF specialized "Comic" Home Defence night fighter variants of the Sopwith 1½ Strutter
Sopwith 1½ Strutter
The Sopwith 1½ Strutter was a British one or two-seat biplane multi-role aircraft of the First World War. It is significant as the first British-designed two seater tractor fighter, and the first British aircraft to enter service with a synchronised machine gun...

 and Sopwith Camel
Sopwith Camel
The Sopwith Camel was a British First World War single-seat biplane fighter introduced on the Western Front in 1917. Manufactured by Sopwith Aviation Company, it had a short-coupled fuselage, heavy, powerful rotary engine, and concentrated fire from twin synchronized machine guns. Though difficult...

s of No. 151 Squadron RAF
No. 151 Squadron RAF
-World War I:No. 151 squadron was founded at Hainault Farm in Essex on 12 June 1918, and was equipped with Sopwith Camel aircraft.During the five months in which 151 Squadron had taken part in hostilities overseas, the total number of hours flown by night was 1443 hrs 26 mins.Sixteen enemy aircraft...

 in 1918 were produced to combat the German bomber and airship raids over Great Britain. The armament was two Lewis mounted on twin Foster mountings in preference to the synchronized
Interrupter gear
An interrupter gear is a device used on military aircraft and warships in order to allow them to target opponents without damaging themselves....

 Vickers
Vickers machine gun
Not to be confused with the Vickers light machine gunThe Vickers machine gun or Vickers gun is a name primarily used to refer to the water-cooled .303 inch machine gun produced by Vickers Limited, originally for the British Army...

 preferred for day fighting located at the upper center-section or fixed to fire upwards in a position that prevented the pilot from losing his "night vision" when the guns fired.
The Sopwith Dolphin, a "multi-gun" fighter design entering operational service at the end of World War I, featured an armament setup of two forward-firing Vickers machine gun
Vickers machine gun
Not to be confused with the Vickers light machine gunThe Vickers machine gun or Vickers gun is a name primarily used to refer to the water-cooled .303 inch machine gun produced by Vickers Limited, originally for the British Army...

s in the usual location just forward of the cockpit, but also had the provision to mount a pair of Lewis machine guns located on the forward cross-tube that comprised part of the cabane strut
Cabane strut
The cabane struts of a biplane aircraft support the upper wing over the fuselage and work in conjunction with other wing components such as spars and flying wires to transmit flight loads....

 structure, and intended to be aimed forwards and upwards as an anti-Zeppelin armament scheme. Similar arrangements were trialled by the Germans in 1917, when Gerhard Fieseler
Gerhard Fieseler
Gerhard Fieseler was a German World War I flying ace, aerobatics champion, and aircraft designer and manufacturer....

 of Jasta 38 fitted two machine guns to a Albatros D.V
Albatros D.V
|-See also:-Bibliography:*Bennett, Leon. Gunning for the Red Baron. College Station, TX: Texas A&M University Press, 2006. ISBN 1-58544-507-X....

, pointing upwards and forwards.

The most convoluted example of a night fighter designed to fight at high altitudes was the abortive Supermarine/Pemberton-Billing P.B.31E Nighthawk
Supermarine Nighthawk
-References:NotesBibliography* Andrews, C.F. and E.B. Morgan. Supermarine Aircraft since 1914. London: Putnam, 1987. ISBN 0-85177-800-3.* Bruce, J.M. Warplanes of the First World War, Volume Three: Fighters. London: Macdonald, 1969. ISBN 356-01490-8....

, the first project of the Supermarine Aviation Works Ltd. The prototype anti-Zeppelin
Zeppelin
A Zeppelin is a type of rigid airship pioneered by the German Count Ferdinand von Zeppelin in the early 20th century. It was based on designs he had outlined in 1874 and detailed in 1893. His plans were reviewed by committee in 1894 and patented in the United States on 14 March 1899...

 fighter had a crew of three to five and an intended endurance of 9–18 hours. For armament, the Nighthawk had a 1½-pounder (37 mm) recoilless Davis gun mounted above the top wing with 20 shells that had a wide arc of fire including upward, and two .303 in (7.7 mm) Lewis gun
Lewis Gun
The Lewis Gun is a World War I–era light machine gun of American design that was perfected and widely used by the British Empire. It was first used in combat in World War I, and continued in service with a number of armed forces through to the end of the Korean War...

s. A trainable searchlight
Searchlight
A searchlight is an apparatus that combines a bright light source with some form of curved reflector or other optics to project a powerful beam of light of approximately parallel rays in a particular direction, usually constructed so that it can be swiveled about.-Military use:The Royal Navy used...

 was nose-mounted. First flown in February 1917, the lumbering fighter could only manage 60 mph (97 km/h) at 6,500 ft (1,981 m) and took an hour to climb to 10,000 ft (3,048 m), which was totally inadequate for intercepting Zeppelins. The project was summarily dropped.

Interwar years

The Boulton Paul Bittern
Boulton Paul Bittern
|-See also:-References:NotesBibliography...

 was a twin-engined night fighter (designed to Specification 27/24) with a planned armament configuration of barbette mounted guns that could be angled upwards for attack against bombers without having to enter a climb. The first of two Bittern prototypes was flown in 1927, although performance was poor and the development stopped.

The Westland C.O.W. Gun Fighter
Westland C.O.W. Gun Fighter
-See also:-References:* James, Derek N. Westland Aircraft since 1915. London: Putnam, 1991. ISBN 0-85177-847-X.* Mason, Francis K. The British Fighter since 1912. Annapolis, Maryland: Naval Institute Press, 1992...

 (1930) and Vickers Type 161
Vickers Type 161
|-See also:...

 (1931) were designed in response to Air Ministry specification F.29/27. This called for an interceptor fighter operating as a stable gun platform for the Coventry Ordnance Works 37 mm autocannon
COW 37 mm gun
The COW 37 mm gun was a British automatic cannon that was developed as a heavy-calibre aircraft weapon.It was trialled in several installations and specified for the Westland C.O.W. Gun Fighter...

 produced by the Coventry Ordnance Works (COW). The COW gun had been developed in 1918 for use in aircraft and had been trialled on the Airco DH.4. The cannon fired 23 oz (0.65 kg) shells and was to be mounted at 45 deg or more above the horizontal. The tactic was to fly below the target bomber or airship, firing upwards into it. The gun firing trials with both types went well, with no detriment to airframe or performance, although the Westland prototype displayed "alarming" handling characteristics. Neither the Type 161 nor its competitor, the Westland C.O.W. Gun Fighter were ordered and no more was heard of this use of the aerial COW gun.

The Boulton Paul Defiant
Boulton Paul Defiant
The Boulton Paul Defiant was a British interceptor aircraft that served with the Royal Air Force early in the Second World War. The Defiant was designed and built by Boulton Paul Aircraft as a "turret fighter", without any forward-firing guns. It was a contemporary of the Royal Navy's Blackburn Roc...

 and the naval Blackburn Roc
Blackburn Roc
|-See also:-References:NotesBibliography* Brew, Alec. The Turret Fighters: Defiant and Roc. Ramsbury, Marlborough, Wiltshire, UK: Crowood Press, 2002. ISBN 1-86126-497-6....

 were two late-1930s British fighter aircraft that carried their armament in turrets giving them a wide range of fire including upwards; the fire of several fighters could then be brought to bear on a target together. The Defiant was put into service in 1939 with the intention to be used against bombers despite the bombers' numerous gun positions. After becoming outclassed as a day fighter, the Defiant moved to the night fighter role where it had some success at night, typically attacking from below and slightly ahead of the target bomber, and well out of its field of defensive fire.

In the United States, the twin-engine Bell YFM-1 Airacuda was designed as a "bomber-destroyer", touted to be "a mobile anti-aircraft platform". Its armament included mainly forward-firing M4 37mm cannon
M4 cannon
The 37 mm Automatic Gun, M4, known as the T9 during development, was a 37 mm autocannon designed by John Browning and used in the Bell P-39 Airacobra and P-63 Kingcobra fighters, as well as experimentally on other designs. It provided interceptors with a weapon that could shoot down any...

 with an accompanying gunner mounted in a forward compartment of each of the two engine nacelle
Nacelle
The nacelle is a cover housing that holds engines, fuel, or equipment on an aircraft. In some cases—for instance in the typical "Farman" type "pusher" aircraft, or the World War II-era P-38 Lightning—an aircraft's cockpit may also be housed in a nacelle, which essentially fills the...

s. Theoretically, the cannon could be aimed in an oblique fashion. Nonetheless, the flight test and operational evaluation of the type proved troublesome and except for initial flight testing in 1937 where full armament was carried, the nacelle cannon armament and the accompanying gunner/loaders were eliminated in the final development aircraft.

Development

Oberleutnant
Oberleutnant
Oberleutnant is a junior officer rank in the militaries of Germany, Switzerland and Austria. In the German Army, it dates from the early 19th century. Translated as "Senior Lieutenant", the rank is typically bestowed upon commissioned officers after five to six years of active duty...

Rudolf Schoenert
Rudolf Schoenert
Rudolf Schoenert was the seventh highest scoring night fighter flying ace in the German Luftwaffe during World War II.For a list of Luftwaffe night fighter aces see List of German World War II night fighter aces. He was also a recipient of the Knight's Cross of the Iron Cross with Oak Leaves...

 of 4./NJG 2 decided to experiment with upward firing guns in 1941 and began trying out upward-firing installations amidst scepticism from his superiors and fellow pilots. The first installation was made late in 1942, in a Dornier Do 17Z-10
Dornier Do 17
The Dornier Do 17, sometimes referred to as the Fliegender Bleistift , was a World War II German light bomber produced by Claudius Dornier's company, Dornier Flugzeugwerke...

 that was also equipped with the early UHF-band version of the FuG 202 Lichtenstein BC
Lichtenstein radar
Lichtenstein radar was a German airborne radar in use during World War II. It was available in at least four major revisions, the FuG 202 Lichtenstein B/C, FuG 212 Lichtenstein C-1, FuG 220 Lichtenstein SN-2 and FuG 228 Lichtenstein SN-3.- FuG 202 Lichtenstein B/C :Early FuG 202 Lichtenstein B/C...

 radar. In July 1942, Schoenert discussed the results of his experiment with General Kammhuber
Josef Kammhuber
Josef Kammhuber was a Career Officer in the German Air Force, and is best known as the first General of the Night Fighters in the Luftwaffe during World War II...

, who authorized the conversion of three Dornier Do 217J-1s
Dornier Do 217
The Dornier Do 217 was a bomber used by German Luftwaffe during World War II as a more powerful version of the Dornier Do 17, known as the Fliegender Bleistift . Designed in 1937 and 1938 as a heavy bomber, its design was refined during 1939 and production began in late 1940...

 to add a vertical armament of four or six MG 151s. Further experimentation was carried out by the Luftwaffe weapons testing centre at Tarnewitz through 1942, and an angle of between 60° and 75° was found to give best results, allowing a target turning at 8°/sec to be kept in the gunsight.

Meanwhile, Schönert was made CO of II./NJG 5, and an armourer serving with the Gruppe, Oberfeldwebel Mahle developed a working arrangement with the unit's Bf 110s mounting a pair of MG FF/M
MG FF cannon
The MG FF was a drum-fed, 20 mm aircraft autocannon, developed in 1936 by Ikaria Werke Berlin of Germany. It was a derivative of the Swiss Oerlikon FF F cannon, itself a development of the German World War I Becker 20 mm cannon, and was designed to be used in fixed or flexible mountings, as...

 20 mm cannon in the rear compartment of the upper fuselage, firing through the canopy. Schönert used such a modified Bf 110 to shoot down a bomber in May 1943. From June 1943 on, an official conversion kit was produced for the Junkers Ju 88
Junkers Ju 88
The Junkers Ju 88 was a World War II German Luftwaffe twin-engine, multi-role aircraft. Designed by Hugo Junkers' company through the services of two American aviation engineers in the mid-1930s, it suffered from a number of technical problems during the later stages of its development and early...

 and Dornier Do 217N
Dornier Do 217
The Dornier Do 217 was a bomber used by German Luftwaffe during World War II as a more powerful version of the Dornier Do 17, known as the Fliegender Bleistift . Designed in 1937 and 1938 as a heavy bomber, its design was refined during 1939 and production began in late 1940...

 fighters. Between August 1943 and the end of the year, Schönert achieved 18 kills with the new gun installation.
Prior to the introduction of Schräge Musik in 1943, German night fighters in the Nachtjagdgeschwader (NJG) were simply heavy fighter
Heavy fighter
A heavy fighter is a fighter aircraft designed to carry heavier weapons or operate at longer ranges. To achieve acceptable performance, most heavy fighters were twin-engined, and many had multi-place crews....

s equipped with radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

 in the nose and a combination of front-firing and defensive weapons. The standard interception involved the fighter approaching the target bomber from the rear in order to get into a firing position. This attack presents the night fighter's crew with a much smaller target area and Royal Air Force
Royal Air Force
The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...

 bombers were all equipped with multi-gun hydraulic rear turrets to help fend off such attacks. The relatively small calibre .303 machine guns that all RAF fighters and bombers used however, did not provide adequate defensive fire power. NJG night fighter pilots then developed a new tactic to avoid the turrets. Instead of approaching directly from the rear, they would approach about 1,500 ft below the bomber. They would then pull up sharply and start firing when the nose of the bomber appeared in the gunsight. As their aircraft slowed and the bomber passed over them, the wings were sprayed with cannon or machine gun rounds. This maneuver was effective, but difficult to perform. There was a significant risk of collision and if the bomb load exploded, it could take down the night fighter too.

Similar systems to the original Schräge Musik cannon installation such as the Sondergerät 500 or Jägerfaust
Jagdfaust
The SG 500 Jagdfaust was an experimental airborne anti-bomber recoilless rifle designed for use in the Me 163 Komet rocket plane by the German Luftwaffe during World War II...

 series of weapon systems were tested on day fighters as well as a variety of other airframes, including the Grosszerstörer experimental version of the He 177 heavy bomber. The Jägerfaust system firing heavy 50 mm projectiles vertically into the lower sides of bombers, was triggered by an optical device. The pilot's only task was passing underneath the targeted bomber. The Jägerfaust was tested on the Fw 190, and was destined for installation in the Me 163B and the Me 262B. The definitive night fighter version of the Messerschmitt Me 262
Messerschmitt Me 262
The Messerschmitt Me 262 Schwalbe was the world's first operational jet-powered fighter aircraft. Design work started before World War II began, but engine problems prevented the aircraft from attaining operational status with the Luftwaffe until mid-1944...

, the Me 262B-2, was also designed to carry such an installation, but the system did not work successfully, and it was not used operationally. Trials with the Komet, however, showed very promising results with six operational aircraft modified. On 10 April 1945, a Halifax bomber was shot down by Fritz Kelb flying a Me 163B Jägerfaust-equipped Komet operating from Brandis, Germany.

As new experimental aircraft were developed for the night fighter role, such as the Horten Ho 229
Horten Ho 229
The Horten H.IX, RLM designation Ho 229 was a late–World War II prototype fighter/bomber designed by Reimar and Walter Horten and built by Gothaer Waggonfabrik...

, the Schräge Musik system was incorporated from the outset. The experimental Horten Ho 229 flying wing series had an unusual upward-firing armament proposed for testing on the V4 night fighter prototype, photoelectric fired vertically mounted rockets or recoilless gun
Recoilless rifle
A recoilless rifle or recoilless gun is a lightweight weapon that fires a heavier projectile than would be practical to fire from a recoiling weapon of comparable size. Technically, only devices that use a rifled barrel are recoilless rifles. Smoothbore variants are recoilless guns...

s instead of cannon armament inspired by the Jagdfaust system's design.

Typical installations

  • Dornier Do 217N: 4 × 20 mm MG 151/20
    MG 151 cannon
    The MG 151 was a 15 mm autocannon produced by Waffenfabrik Mauser starting in 1940. It was in 1941 developed into the 20 mm MG 151/20 cannon which was widely used on many types of German Luftwaffe fighters, fighter bombers, night fighters, ground attack and even bombers as part of or as...

  • Focke-Wulf Fw 189
    Focke-Wulf Fw 189
    |-See also:-References:NotesBibliography* Brown, Capt. Eric . Wings of the Luftwaffe. Garden City, NY: Doubleday & Company, Inc., 1978. ISBN 0-385-13521-1....

    : 1 × 20 mm MG151/20 (used mainly on Eastern Front)
  • Heinkel He 219: 2 × 30 mm MK 108
  • Junkers Ju 88C/G: 2 × 20 mm MG 151/20
  • Junkers Ju 388J
    Junkers Ju 388
    The Junkers Ju 388 Störtebeker was a World War II German Luftwaffe multi-role aircraft based on the Ju 88 airframe by way of the Ju 188. It differed from its predecessors in being intended for high altitude operation, with design features such as a pressurized cockpit for its crew...

    : 2 × 30 mm MK 108
  • Messerschmitt Bf 110
    Messerschmitt Bf 110
    The Messerschmitt Bf 110, often called Me 110, was a twin-engine heavy fighter in the service of the Luftwaffe during World War II. Hermann Göring was a proponent of the Bf 110, and nicknamed it his Eisenseiten...

    G-4: 2 × 20 mm MG FF/M
  • Messerschmitt Me 262B-2: 2 × 30 mm MK 108
  • Focke-Wulf Ta 154
    Focke-Wulf Ta 154
    |-See also:-External links:*...

    : 2 × 30 mm MK 108

Method of sighting guns

In the ubiquitous Ju 88G-6 night fighter, which was both fast and manouevrable, the Revi 16N gunsight was modified to allow the pilot to aim at the target by placing a reflecting mirror above the pilot’s head, parallel to a similar mirror placed behind the actual gunsight (where the eye would normally be) which itself was further to the rear, functioning together in the manner of a periscope
Periscope
A periscope is an instrument for observation from a concealed position. In its simplest form it consists of a tube with mirrors at each end set parallel to each other at a 45-degree angle....

. The Ju 88G-6 was guided into position from sighting and final approach by commands from the radar operator, with the pilot only taking over when visual contact was made just prior to firing.

"What a contrast with SCHRÄGE MUSIK! Again the technique was to approach deliberately at a lower level, but this time all the night fighter pilot had to do was slow up a little, rise up below the bomber and hold formation. An NJG experte could follow his observer's directions, acquire the bomber visually, close and destroy it within 60 seconds. The firing position, with the bomber 65° to 70° above the fighter, was an almost ideal one. The fighter could see the bomber clearly, as a darker silhouette either blotting out the stars or against paler sky or high cloud. It presented the biggest possible target and reflected any light from searchlights, ground fires or TIs. With the two aircraft in close formation, there was an ideal no-deflection shot. And the fighter was perfectly safe, because it was well below the MONICA beam and could not be seen by any member of the bomber's crew. The only snag was that the Luftwaffe's guns were so effective that the night fighter usually had to get out of the way very fast. It was rather like 1916, except that a Lancaster with one wing blown off tumbled downwards and backwards faster than an ignited airship.”

Operational use

Schräge Musik (or Schrägwaffen, as it was also called) was first used operationally during Operation Hydra (the first instance of the Allied bombing of Peenemünde
Bombing of Peenemünde in World War II
Operation Hydra was a Royal Air Force attack on the Peenemünde Army Research Center on the night of 17/18 August 1943. It began the Operation Crossbow strategic bombing campaign against Nazi Germany's V-weapon programme...

) on 17/18 August 1943. Three waves of aircraft bombed the area, and a successful diversionary raid on Berlin by RAF Mosquitoes attracted the main Luftwaffe fighter effort and meant that only the last of the three waves was met by any sizable group of night fighters. The two Groups of the third wave, 5 Group
No. 5 Group RAF
No. 5 Group was a Royal Air Force bomber group of the Second World War, led during the latter part by AVM Sir Ralph Cochrane.-History:The Group was formed on 1 September 1937 with headquarters at RAF Mildenhall....

 and the RCAF 6 Group
No. 6 Group RCAF
No. 6 Group RCAF was an organization of Royal Canadian Air Force bomber squadrons which operated from airfields in Yorkshire, England during the Second World War. Although 6 Group was RCAF, it was controlled by the Royal Air Force as part of Bomber Command. No. 6 Group had been previously active...

, lost 29 of their 166 bombers, well over the 10% losses considered "unsustainable". In this raid, a total of 40 aircraft were lost: 23 Lancasters, 15 Halifaxes and two Short Stirling
Short Stirling
The Short Stirling was the first four-engined British heavy bomber of the Second World War. The Stirling was designed and built by Short Brothers to an Air Ministry specification from 1936, and entered service in 1941...

s.

Wide-scale adoption followed in late 1943, and by 1944, a third of all German night fighters carried upward-firing guns. Schräge Musik proved to be most successful in the Jumo 213
Junkers Jumo 213
|-See also:-Bibliography:* Jane's Fighting Aircraft of World War II. London. Studio Editions Ltd, 1989. ISBN 0-517-67964-7-External links:*...

 powered Ju 88G-6. An increasing number of these installations used the more powerful 30 mm calibre, short-barreled MK 108 cannon
MK 108 cannon
The MK 108 was a 30 mm caliber autocannon manufactured in Germany during World War II by Rheinmetall-Borsig for use in aircraft.-Development:...

, such as those retroactively fitted to the Heinkel He 219
Heinkel He 219
The Heinkel He 219 Uhu was a night fighter that served with the German Luftwaffe in the later stages of World War II. A relatively sophisticated design, the He 219 possessed a variety of innovations, including an advanced VHF-band intercept radar...

. By mid-1944, however, He 219 aircrew were criticizing the MK 108 installation because its low muzzle velocity and limited range meant that the night fighter had to be positioned relatively close to the bomber being attacked, with damage ensuing from debris. They demanded that either the MK 108s be removed and replaced by MG FF/Ms or the angle of the mounting be changed. Although He 219s continued to be delivered with the twin 30 mm mounted, these were removed by front line units. Using the Schräge Musik required precise timing and swift evasion; a fatally damaged bomber could fall directly upon the night fighter who had just shot it down if the fighter could not quickly turn away. The He 219 was particularly prone to this; its high wing loading
Wing loading
In aerodynamics, wing loading is the loaded weight of the aircraft divided by the area of the wing. The faster an aircraft flies, the more lift is produced by each unit area of wing, so a smaller wing can carry the same weight in level flight, operating at a higher wing loading. Correspondingly,...

 at the edge of stalling speed, left it unmanouevrable, and the 61-victory night fighter ace Manfred Meurer
Manfred Meurer
Manfred Meurer was a Luftwaffe night fighter flying ace of World War II. Meurer was credited with 65 aerial victories claimed in 130 combat missions.For a list of Luftwaffe night fighter aces see List of German World War II night fighter aces He was also a recipient of the Knight's Cross of the...

 lost his life 21/22 January 1944 when, after shooting down a Handley Page Halifax
Handley Page Halifax
The Handley Page Halifax was one of the British front-line, four-engined heavy bombers of the Royal Air Force during the Second World War. A contemporary of the famous Avro Lancaster, the Halifax remained in service until the end of the war, performing a variety of duties in addition to bombing...

 bomber, his He 219 was rammed by a Bf 110.

Schräge Musik allowed German night fighters to attack undetected, using special ammunition with a faint glowing trail replacing the standard tracers, combined with a "lethal mixture of armour-piercing, explosive and incendiary ammunition." Approaching from below provided the night fighter crew with the advantage that the bomber crew could not see the night fighter against the dark ground or sky, yet allowed the German crew to observe and identify the silhouette of the aircraft before they attacked. The optimum target for the night fighter was the wing fuel tanks, not the fuselage or bomb bay, because of the risk that exploding bombs would damage the attacker. “To overcome some of the problems, many NJG pilots closed the range at a lower level, below the MONICA
Monica tail warning radar
Monica was a range-only tail warning radar for bombers, introduced by the RAF in the spring of 1942. Officially known as ARI 5664, it operated at frequencies of around 300 MHz...

 zone of coverage, until they could see the bomber above; then they pulled up into a climb with all front guns blazing. But this demanded fine judgment, gave only a second or two of firing time and almost immediately brought the fighter up behind the bomber's tail turret.

Schräge Musik produced devastating results with its most successful deployment in the winter of 1943–1944. This was a time when losses became unacceptable: the RAF losing 78 of 823 bombers that attacked Leipzig on 19 February, and 107 of the 795 bombers that attacked Berlin on 30 March. RAF Bomber Command was slow to react to the threat from Schräge Musik, with no reports from downed crews confirming the new menace in the skies. The sudden increase in bomber losses had often been attributed to flak. Initial reports from air gunners of German night fighters stalking their prey from below had appeared as early as 1943, but had been discounted. An urban myth developed around reports, made by RAF Bomber Command crews, who claimed "scarecrow shells" were encountered over Germany. The phenomenon was thought to be "AA shells simulating an exploding four-engined bomber and designed to damage morale. Sadly, in many cases these were actual 'kills' by Luftwaffe night fighters... It was not for many months that evidence of these deadly attacks was accepted."

A detailed analysis of the damage done to returning bombers clearly indicated that the night fighters were firing from below. Defense against the attacks included mixing de Havilland Mosquito
De Havilland Mosquito
The de Havilland DH.98 Mosquito was a British multi-role combat aircraft that served during the Second World War and the postwar era. It was known affectionately as the "Mossie" to its crews and was also nicknamed "The Wooden Wonder"...

 night fighters into the bomber stream, attempting to pick up radar emissions from the German night fighters. Wing Commander J.D. Pattinson of 429 "Bison" Squadron, recognized an unseen danger but to him, it "was all presumption, not fact." He ordered that the mid-upper turrets be removed and the "displaced gunner would lie on a mattress on the floor as an observer, looking through a perspex blister for night fighters coming up from below." While many Lancaster B. IIs had retained the FN64 ventral turret, a small number of Halifax and Lancaster bombers were unofficially fitted with a single machine gun installation in either a ventral turret or a makeshift port directly under the mid-upper gunner station.

Even in the last year of the war, 18 months after the Peenemunde Raid, Schräge Musik night fighters were still taking a fearful toll, for example on the Mitteland-Ems Canal Raid, 21 February 1945:

“On this particular night the night fighters were to score heavily. The ground radar stations responsible for initial guidance to the vicinity of the bombers did their job well, as did the airborne radar operators to whom fell the task of final location of individual targets. The path of the returning bomber stream was clearly marked by the pyres of numerous downed victims. NJG-4 was operating from Gutersloh (later an RAF base
RAF Gütersloh
The former Royal Air Force Station Gütersloh, more commonly known as RAF Gütersloh, was a Royal Air Force Germany military airbase, the nearest Royal Air Force airbase to the East/West German border, in the vicinity of the town of Gütersloh. It was constructed by the Germans prior to World War II...

) and in the space of 20 minutes, between 20.43 and 21.03, Schnaufer and his crew, using their upward firing cannons, shot down seven Lancasters. As it was, on that black night, four night fighter crews accounted for 28 of the 62 bombers lost out of the 800 despatched.”

Japan

In 1943, Commander Yasuna Kozono of the 251st Kokutai, Japanese Imperial Navy in Rabaul came up with the idea of converting the Nakajima J1N
Nakajima J1N
-See also:-Bibliography:* Francillon, Réne J. Japanese Aircraft of the Pacific War. London: Putnam & Company Ltd., 1970 . ISBN 0-370-30251-6....

 (J1N1-C) into a night fighter. On 21 May 1943, about the same time as the Luftwaffe had its first victory with Schräge Musik in Europe, the field-modified J1N1-C KAI shot down two B-17s of 43rd Bomb Group attacking air bases around Rabaul. The Navy took immediate notice and placed orders with Nakajima for the newly designated J1N1-S night fighter design. This model was christened the Model 11 Gekko (月光, "Moonlight"). It required only two crew and like the KAI, had a twin 20 mm pair of Type 99 Model 1 cannon firing upward and a second pair firing downward at a forward 30° angle, placed in the fuselage behind the cabin.

The Japanese Army Air Force's Mitsubishi Ki-46
Mitsubishi Ki-46
The Mitsubishi Ki-46 was a twin-engine reconnaissance aircraft used by the Imperial Japanese Army in World War II. Its Army Shiki designation was Type 100 Command Reconnaissance Aircraft ; the Allied nickname was "Dinah"....

 "Dinah" twin engined fighter was used to test the Schräge Musik armament format in its Ki-46 III KAI version in June 1943, using a 37 mm Ho-203 cannon
Ho-203 cannon
Ho-203 was a Japanese autocannon that saw considerable use during World War II. It was a long-recoil automation of the Year 11 Type direct-fire infantry gun. It was fed by a 15-round closed-loop ammunition belt...

 with 200 rounds of ammunition. It was mounted in virtually the same position in the fuselage as in the Luftwaffe fighters. Operational deployment began in October 1944.

One of the main Japanese fighters using this device was the Kawasaki Ki-45
Kawasaki Ki-45
The Kawasaki Ki-45 Toryu was a two-seat, twin-engine fighter used by the Imperial Japanese Army in World War II. The army gave it the designation "Type 2 Two-Seat Fighter"; the Allied reporting name was "Nick"....

 "Nick". The Japanese Navy air forces also used the Schräge Musik installation with the Nakajima J1N1-S
Nakajima J1N
-See also:-Bibliography:* Francillon, Réne J. Japanese Aircraft of the Pacific War. London: Putnam & Company Ltd., 1970 . ISBN 0-370-30251-6....

 "Gekko" (two or three 20mm cannons firing upwards, some had two firing downwards), and a pair of 20 mm Type 99 cannon
Type 99 cannon
The Type 99-1 cannon and Type 99-2 cannon were Japanese versions of the Oerlikon FF and Oerlikon FFL. They were adopted by the Imperial Japanese Navy in 1939 and served as their standard aircraft autocannon during World War II.-Adoption:...

s in the Nakajima C6N1-S
Nakajima C6N
-See also:-References:NotesBibliography* Francillon, Ph.D., René J. Japanese Aircraft of the Pacific War. London: Putnam & Company Ltd., 1970. ISBN 0-370-00033-1 ....

 "Myrt".

United Kingdom

The Boulton Paul Defiant
Boulton Paul Defiant
The Boulton Paul Defiant was a British interceptor aircraft that served with the Royal Air Force early in the Second World War. The Defiant was designed and built by Boulton Paul Aircraft as a "turret fighter", without any forward-firing guns. It was a contemporary of the Royal Navy's Blackburn Roc...

 "turret fighter" was originally conceived (F.11/37 and .F.9/35 specifications for a "two-seat day and night fighter... which gave birth to the Defiant") to defend Great Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...

 against massed formations of unescorted enemy bombers. Regardless of the requirement, the use of its dorsal turret was predicated on the "broadside" fighter interception and combined fighter attack tactic in bomber interception. The circumstances that caused the woeful Defiant to take on single-seat fighters led to catastrophic results in 1940 over France and during the Battle of Britain
Battle of Britain
The Battle of Britain is the name given to the World War II air campaign waged by the German Air Force against the United Kingdom during the summer and autumn of 1940...

. With untenable losses in day operations, the Defiant was transferred to night fighting and there the type achieved some success. Defiant night fighters typically attacked enemy bombers from below in a similar manoeuvre to the later successful German Schräge Musik attacks, more often from slightly ahead or to one side, rather than from directly under the tail. During the winter Blitz
The Blitz
The Blitz was the sustained strategic bombing of Britain by Nazi Germany between 7 September 1940 and 10 May 1941, during the Second World War. The city of London was bombed by the Luftwaffe for 76 consecutive nights and many towns and cities across the country followed...

on London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

 of 1940–41, the Defiant equipped four squadrons, shooting down more enemy aircraft than any other type. The Defiant Mk II variant was fitted with the AI Mk IV airborne interception radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

 and a Merlin XX engine. A total of 207 Mk II Defiants were built but the use of the turret fighter as a night fighter was short-lived as Beaufighter
Bristol Beaufighter
The Bristol Type 156 Beaufighter, often referred to as simply the Beau, was a British long-range heavy fighter modification of the Bristol Aeroplane Company's earlier Beaufort torpedo bomber design...

 and Mosquito
De Havilland Mosquito
The de Havilland DH.98 Mosquito was a British multi-role combat aircraft that served during the Second World War and the postwar era. It was known affectionately as the "Mossie" to its crews and was also nicknamed "The Wooden Wonder"...

 night fighters came on line in 1941 and 1942, respectively.

United States

The American Northrop
Northrop Corporation
Northrop Corporation was a leading United States aircraft manufacturer from its formation in 1939 until its merger with Grumman to form Northrop Grumman in 1994. The company is known for its development of the flying wing design, although only a few of these have entered service.-History:Jack...

 P-61 Black Widow
P-61 Black Widow
The Northrop P-61 Black Widow was the first operational U.S. military aircraft designed specifically for night interception of aircraft, and was the first aircraft specifically designed to use radar. It was an all-metal, twin-engine, twin-boom design developed during World War II...

 night fighter could deliver a Schräge Musik–like surprise of its own, from below an enemy aircraft, because of the design of its remote dorsal turret carrying a quartet of .50 Caliber Browning M2 machine guns.

Postwar

The Northrop F-89 Scorpion was originally designed to meet the 1945 United States Army Air Forces
United States Army Air Forces
The United States Army Air Forces was the military aviation arm of the United States of America during and immediately after World War II, and the direct predecessor of the United States Air Force....

 Army Air Technical Service Command specification ("Military Characteristics for All-Weather Fighting Aircraft") for a jet-powered night fighter to replace the P-61 Black Widow. The N-24 company proposal was armed with four 20 mm (.79 in) cannon in a unique trainable nose turret
Gun turret
A gun turret is a weapon mount that protects the crew or mechanism of a projectile-firing weapon and at the same time lets the weapon be aimed and fired in many directions.The turret is also a rotating weapon platform...

 that could rotate 360˚ with the guns able to elevate to 105˚. Ultimately, the F-89 design abandoned the swiveling nose turret in favor of a more standard front-firing cannon arrangement.

In 1947, the United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...

 tested a Schräge Musik gun installation on a Lockheed F-80A Shooting Star standard "day fighter" aircraft (s/n 44-85044) to study the ability to attack Soviet bombers from below. Twin 0.5 in (12.7 mm) machine guns were fixed in an oblique mount.

A final attempt to exploit a fully traversing turret was found in the original 1948 design of the Curtiss-Wright XF-87 Blackhawk all-weather jet fighter interceptor. Armament was to be a nose-mounted, powered turret containing four 20 mm (.79 in) cannon, but this installation was only fitted to the mock-up and never incorporated in the two prototypes.

Some Soviet jet fighter prototypes of the late-1940s/early-1950s era included cannon mounted in the nose that were capable of being trained in elevation, however none achieved production status.

Analysis

Freeman Dyson
Freeman Dyson
Freeman John Dyson FRS is a British-born American theoretical physicist and mathematician, famous for his work in quantum field theory, solid-state physics, astronomy and nuclear engineering. Dyson is a member of the Board of Sponsors of the Bulletin of the Atomic Scientists...

, who was an analyst for Operations research
Operations research
Operations research is an interdisciplinary mathematical science that focuses on the effective use of technology by organizations...

 of RAF Bomber Command
RAF Bomber Command
RAF Bomber Command controlled the RAF's bomber forces from 1936 to 1968. During World War II the command destroyed a significant proportion of Nazi Germany's industries and many German cities, and in the 1960s stood at the peak of its postwar military power with the V bombers and a supplemental...

in World War II, commented on the effectiveness of Schräge Musik: "The cause of losses... killed novice and expert crews impartially. This result contradicted the official dogma... I blame the ORS and I blame myself in particular, for not taking this result seriously enough... If we had taken the evidence more seriously, we might have discovered Schräge Musik in time to respond with effective countermeasures."

External links

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