Can the cannon on the fighter plane only shoot forward?

Most of the fighters in World War II had only one weapon, so the cannon at that time was rotatable and had a large angle. Modern fighter weapons are mainly missiles, supplemented by cannons, and cannot rotate. If they rotate, they can't catch up with high-speed moving enemy planes.

The reason why machine guns have not been eliminated in modern fighters is mainly because of the following points:

1) The missiles of fighter planes are still very limited, usually a few to a dozen. When the missiles are not replenished after being shot (just like fighting for a bayonet after being shot), the cannon becomes the only weapon.

2) After the missile is launched, there is usually a certain reaction distance, which is the blind area of missile attack, such as within a few hundred meters (different missiles have different blind areas), and then the cannon becomes the main weapon.

3) The caliber of air guns is generally 20-40MM, and the maximum range is only a few kilometers. In air combat, especially in the face of modern high-speed and high-mobility fighters, it seems to be more and more inadequate, but its advantage is that it is simple and cheap, and does not occupy the load of many fighters.

4) Another use of air guns is to attack the ground. On fighter planes (especially those without bombs or surface-to-surface missiles), air guns are the main or only air attack method, because it is not practical to attack ground targets with air-to-air missiles after all.