Oerlikon FF
The Oerlikon FF is based on the 20 mm Becker cannon , the world's first light machine gun , during the First World War by the German engineer Reinhold Becker was developed. In the 1920s, following the acquisition of patents, the machine tool factory in Oerlikon further developed the weapon into an on-board cannon for aircraft. The name FF means "wing fixed" because the weapon was built into the wing. It was one of the first 20mm cannons to be light enough to be inserted into the wings of aircraft. The FF series served as a template for many 20 mm cannons in World War II, the German MG FF and its variants, the Japanese Type 99 cannon and the anti-aircraft cannons that functioned on the same principle.
The original design, which was introduced as the FF , was a cannon with an unlocked mass shutter and therefore limited in its performance. The ammunition used were cartridges with the dimensions 20 × 72 mm, the projectiles of which reached a muzzle velocity of 600 meters per second (m / s) with a weight of 128 grams and were fired at a rate of 520 rounds per minute. The gun weighed 24 kilograms. The low muzzle velocity was of central importance, so that the later development FF L (a 30-kilogram weapon) fired 20 × 101 mm cartridges at a speed of 750 m / s. The 39 kilogram FF S fired cartridges of 20 × 110 mm at a speed of 830 m / s with a slightly lower rate of 470 rounds per minute. The original weapon has since FF F called.
The FF F was manufactured under license in Japan as Type 99-1 , the FF L as Type 99-2 .
Hispano-Suiza manufactured the FF S as HS.7 and, in a slightly modified form, the HS.9 in France , but after 1930 developed the Hispano-Suiza-HS.404 series, which was later used by the French, British, Swiss and American armies , a gas pressure charger . This and its successors, improved in their performance, were one of the best 20 mm cannons of the Second World War.
In Germany, the Berlin-based Ikaria Society for Aircraft Accessories in Velten produced the FF F with a slightly stronger 20 × 80 mm cartridge than the MG FF . Later a mine projectile was introduced, which had a thinner, pressed projectile shell instead of a milled one, which increased the proportion of explosives. The result was the FF / M , which was standard until 1941. At the end of 1940 these weapons were replaced by the completely different MG 151/20 .
20 mm guns
Surname | cartridge | Bullet weight |
cadence | Muzzle velocity |
Gun weight |
---|---|---|---|---|---|
(Grams) | (rpm) | (m / s) | (kg) | ||
France | |||||
HS.9 | 20 × 110RB | 122 | 360-420 | 830 | 48 |
HS.404 | 20 × 110 | 130 | 700 | 880 | 60 |
Germany | |||||
MG FF | 20 × 80RB | 134 | 520 | 600 | 28 |
MG FF / M | 20 × 80RB | 92/115 | 540/520 | 700/585 | 28 |
MG 151/20 | 20 × 82 | 92/115 | 750-800 | 800/720 | 42 |
Japanese army | |||||
Type 94 flexible | 20 × 99RB | 127 | 380 | 675 | 43 |
Ho-1 | 20 × 125 | 144 | 400 | 805 | 45 |
Ho-3 | 20 × 125 | 144 | 400 | 805 | 45 |
Ho-5 | 20 × 94 | 96 | 750-850 | 715 | 37 |
Japanese Navy | |||||
Type 99-1 | 20 × 72RB | 129 | 520 | 525 | 26th |
Type 99-2 | 20 × 101RB | 128 | 490 | 750 | 34 |
Great Britain | |||||
Hispano Mk.II | 20 × 110 | 130 | 600 | 880 | 50 |
Hispano Mk.V | 20 × 110 | 130 | 750 | 840 | 42 |
Soviet Union | |||||
SchWAK | 20 × 99 mm r | 95 | 800 | 750-770 | 42 |
Beresin B-20 | 20 × 99 mm r | 95 | 800 | 750-770 | 25th |
Web links
Individual evidence
- ↑ George M. Chinn: Chapter 5. Becker-Semag-Oerlikon Automatic Aircraft Cannons. In: The Machine Gun: History, Evolution, and Development of Manual, Automatic, and Airborne Repeating Weapons (Vol. I / Part V). ibiblio.org, 1951, accessed on September 17, 2015 (English) PART V AUTOMATIC AIRCRAFT CANNON ( Memento from September 30, 2017 in the Internet Archive )
- ↑ Popular Science, September 1943 issue, A Photo History of Arms , pp. 86 ff.