I MUST KNOW HOW THEY DO IT !!?

Question

Ever since I found out about fighter planes that uses propellers with a machine gun in front of the pilot;I always wondered how the bullets would pass through the propeller without damaging it or destroying it. =)

Answer 1

Actually, destroying the propeller is exactly what the early fighter pilots did when they first used the forward firing center mounted machine guns. Soon after, a method of synchronization was developed so the gun could only fire at a precise time during the arch of the propeller. It uses a cam shaft running off of the engine integrated with the firing mechanism of the machine gun. When the trigger is pulled, the machine gun firing mechanism is essentially interrupted until the cam shaft enables it.

Although a little more complicated, it uses the same principle as a camshaft opening and closing the intake and exhaust valves on an internal combustion engine. A spring always holds tension against the valves to keep them closed until the camshaft rotates to a position where a high spot (or lobe) on the shaft pushes a rod to force the valve open. As the camshaft rotates past the lobe the spring forces the valve back into it's normal closed position.

Answer 2

There were several solutions to that problem.

1) metal backing to the propeller, make it bullet resistant, but all that ricochet must go somewhere... Hmmm...

2) make the cannon / MG fire THROUGH the central axle of the propeller. Yes, it's quite possible.

3) Put the gun up HIGH, above the propeller's arc, on the top wing, pointing slightly downward. Some French planes did this.

4) The German "interrupt gear", which interrupts the MG as the propeller sweeps by.

5) Put the guns in the wings, outside the propeller arc, pinting slightly inwards.

Answer 3

Prop fighter planes had a device called a synchronizing gear, which, like the name implies synchronized the gun and propeller so that the bullets were fired when the propeller blade was not in front of the gun barrel. If the blade was in front of the barrel, the gun trigger was disabled.

Answer 4

In the early days of WWI air combat, some pilots actually did have the unfortunate experience of shooting themselves down by damaging their propeller when firing through it. The first protection developed was to put a metal shield behind the prop to prevent their bullets from striking the wooden propeller blades. Later, a trigger interruptor was invented which stopped the guns from firing when a prop blade was in the line of fire.

By WWII, most fighter aircraft had their guns placed in the wings where the bullets would not interfere with the prop. There were actually a few fighter planes with heavy guns that fired through the center of the prop

Answer 5

The guns were synchronized with the propeller to fire when the propeller blades were not in line with the gun. Even at full speed, the bullet is always faster than a propeller.

Answer 6

They have an interrupter (synchronizer) that momentarily stops the gun from firing when the propeller is in the way.
In WWI, the French (figures) tried plates of steel on the back of the prop. The problem was, the pilot had to dodge the ricocheting bullets from his own gun also.

Answer 7

the gun is hooked up to the propellers motor and fires in sequence with the rotation of the propeller so each bullet will be fired between each blade. Its really a simple design

Answer 8

a mechanical sensor would detect when it was safe to fire. since the bullet travels faster than sound it was not going to hit the propeller....later WWII aircraft then had innerwing mounted guns for more fire power and would not be effected by the propeller

Answer 9

Magic

Answer 10

it's called synchronization :)