
This apparently happened by mistake, but when you look at some of the facts, that mistake was a big one. By all accounts, it was not a dark and stormy night back on October 11 2018 at Belgium’s Florennes Air Force Base. Its located about 4 kilometres South East of the city of Florennes in the Walloon municipality.
Base authorities say a maintenance worker accidentally caused a 20mm Vulcan cannon to open fire from an F-16 jet on which he was working, destroying an F-16 parked opposite, while damaging another aircraft nearby. Miraculously no-one was hurt in the incident but one F-16 took the full brunt of the Vulcan, it caught fire and exploded as it was fully loaded with fuel awaiting an afternoon sortie.
“You can’t help thinking of what a disaster this could have been,” said Col. Didier Polome, the base commander, speaking to Belgium TV.

Two fighter squadrons operate out of the Airbase, 1 Squadron which dates back to 1917, and 350 Squadron, founded in the UK in 1942 during the Second World War.
Both units fly the F-16 Falcon.
But how could a maintenance worker mistakenly trigger a dangerous high speed cannon that fires more than 70 rounds in 0.5 seconds? That’s enough power to literally rip a wall in half. In this case it appears the cannon rounds missed a wall erected between the hangar and the apron, passing through a small gap. For more read on.

There are a few things here that need clarity. For instance, what was a fully armed F-16 jet doing inside a hangar being worked on by an engineer? Surely even in an operation environment, the jet is “made safe” before someone goes tinkering on the vehicle? Again, I try answer this below.
The 20MM Vulcan is a gatling gun, which means its not just a cannon, its a cannon with an attitude. As the 6 barrels revolve, they proceed through the different stages of the gun firing cycle, which produces an utterly terrifying firing rate of 6,600 rounds per minute.
The engineer apparently let fly for a few seconds. Maybe two seconds. That means 120 High Explosive or Armour-Piercing rounds flew out of the hangar and into the parked F-16. It blew up almost instantly according to reports.

Rules governing armed jets and maintenance
If the F-16 is to undergo light maintenance, which involves a series of checks more than anything else, only the bombs and missiles are removed from the plane. After this incident, perhaps they should consider removing the massive ammunition drum too.
There is a process to make the Vulcan 20mm Cannon safe during storage and maintenance.
It takes the following, according to the F-16 Flight Manual.
- Rounds limiter switch set to ON with rounds counter set to 990. (set to OFF or ON with 510 or less on counter when hot gun needed)
- Electrical safety pin installed. (Removed when hot gun needed)
- Clearing sector holdback toll installed. (Removed when hot gun needed)
The really important note here is that every single step above must be taken to ensure the gun won’t fire on its own.
It takes a huge 35 horse power to actually fire this weapon, with it’s massive alloy barrel and the pressures required to move 20mm shells so quickly.
So either it needs the engine running, or a hydraulic test rig to be setup which is used to check landing gear, flight controls, brakes and the gun system.
But the big problem is how to setup “fire on the ground” options. It goes like this
- Find the GND JETT switch and switch to ENABLE.
- Select gun mode (A/A or A/G)
- Select Master Arm switch to arm and
- Press the trigger.

So as you can see, dear friends, all of the above means someone has to have screwed up really, really badly to have managed to fire one of the most lethal cannons every designed on the ground into your own airforce.
I’m not suggesting anything like a conspiracy, just that it is a truly shocking event that fortunately ended well compared to what could have happened had these rounds missed the F-16 and hit a motorway or similar nearby.
Need I say that the Belgian Air Force is investigating?