The relief you should feel when you hear the M61 Vulcan cannon of an F/A-18 Hornet fighter

In the world of aviation, without a doubt the most famous cannon is the GAU-8 of the A-10 Thunderbolt II attack aircraft, a 30 mm gatling cannon.

The shots with live ammunition of Swiss F/A-18C fighters at an alpine airshow
This is how the GAU-8 Avenger works: the powerful and huge rotary cannon of the A-10

However, the most widespread cannon among Western fighter aircraft is the M61 Vulcan, also a Gatling gun (i.e., a rotating cannon) but with a 20 mm caliber and six barrels (the A-10 has seven). Introduced in the 1950s, the first aircraft to use it was the Lockheed F-104 Starfighter. In recent decades, the M61 has been used by fighters such as the F-14 Tomcat, the F-15 Eagle, the F-16 Fighting Falcon, the F/A-18 Hornet, and the F-22 Raptor.

The F/A-18 Hornet is the only one of the aforementioned aircraft that has the M61 Vulcan gun installed in the center of the fuselage, specifically the M61A1 or M61A2 version (the latter being lighter) in the nose, just behind the radar and in front of the cockpit. Beneath the gun is an ammunition hopper with a capacity of 578 rounds and a closed-loop, linkless rotary feed system, meaning that spent cartridges are stored, preventing links or discarded cartridges from accidentally entering the air intakes and from there the engines.

The M61 Vulcan has a rate of fire of 6,000 rounds per minute, meaning it can fire 100 projectiles per second. The cartridge used, the PGU-28, weighs 272 grams and is 168 mm long (slightly longer than a soda can). The projectile (the part that is fired) weighs 100 grams and can be of different types. The projectile reaches a speed of 1,050 meters per second, more than three times the speed of sound.

The maximum effective range of the M61 cannon is 3,000 meters. Doing some simple calculations, this means that if you're 3 km from that fighter and it fires at you, you could be hit by a hail of more than 200 rounds before you even hear the shot. The sound would reach you only after you've been shot to pieces. So, as with the A-10, you should feel relieved to hear the M61 Vulcan cannon of an F/A-18 Hornet fighter, because it means you're not the target.

You can get an idea of ​​this by watching this video posted on Sunday by The Change In Time, which shows four Swiss Air Force F/A-18C fighter jets firing their M61 Vulcan cannons at AXALP, one of Europe's most spectacular air shows, held annually in the Swiss Alps. It is one of the few European events of its kind that includes live-fire demonstrations. If you look closely at the footage, the smoke generated by the M61 cannon fire appears on the target before the sound of the shot is even heard:

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Main photo: Swiss Air Force.