If you've ever gazed up at a jet streaking across the sky and wondered, “How does that thing not run out of fuel?” — you're not alone. It's one of the most frequent questions I get. At first glance, it seems almost magical: giant metal birds flying thousands of miles non-stop. But the truth is far more fascinating — and entirely grounded in science, engineering, and meticulous planning.

Let’s break it down.

Grab yourself a coffee before we get stuck into the nitty gritty!!

The Simple Supermarket Analogy 

I’m going to make this really simple by comparing it to something in everyday life.

Imagine your car is parked outside your house, but it doesn’t have any fuel in it. You want to drive to the supermarket, but how much fuel do you actually need? You might think, “Just give me a full tank of petrol, please” — and that’s fine.

But here’s the thing: the heavier the plane, the more fuel it burns. The more fuel it burns, the more money the airline spends, and the greater the environmental impact. On top of that, if the plane is full of passengers and luggage, taking a full tank of fuel might put it over the maximum take-off weight — and obviously, that’s a no-go.

So, let’s go back to the car and supermarket example…

The refueller walks up to your car, rings the doorbell, and asks, “How much fuel would you like?”

You think it through and decide:

• You’ll need some fuel just to warm up or cool down the car while it’s sitting on the driveway before setting off — we’ll call that Taxi Fuel.

• Of course, you’ll need enough fuel to get from your house to the supermarket — we’ll call that Trip Fuel.

That sounds like enough, right? Sure, it’ll get you there. But what if the supermarket is closed when you arrive?

In that case, you’ll need to go to a different one — so you take enough fuel for that too. We’ll call it Alternate Fuel.

Just to be on the safe side, you also add an extra 5% of your trip fuel, or 5 minutes' worth — whichever is greater. That’s Contingency Fuel.

Now you’re covered, right? Almost. But just in case everything goes wrong, you also take an additional 30 minutes of fuel as a last-resort backup. That’s called Final Reserve Fuel.

Lastly, if you, the driver, think there might be traffic, roadworks, or any other delay, you can request as much additional fuel as you like. That’s called Extra Fuel.

And that’s why it’s extremely rare for an airliner to run out of fuel — it’s all carefully planned, with plenty of backup.

Fuel Planning

Let’s now move from the supermarket analogy back into aviation.

On our flight plan we will plan our fuel, we carry a specific amount of fuel — and each part of it has a defined purpose:

Taxi Fuel: The amount of fuel expected to be used on the ground before take-off (for taxiing to the runway).

Trip Fuel: The fuel required to fly from take-off to landing at the planned destination.

Contingency Fuel: An additional 5% of the trip fuel, or no less than 5 minutes’ worth — to cover unexpected factors like wind changes or minor route deviations.

Alternate Fuel: Enough fuel to divert from the planned destination to an alternate airport, in case you can’t land where originally planned.

Final Reserve Fuel: A mandatory 30 minutes of fuel at holding speed at 1,500 feet above the airport — for use only as a last resort.

Extra Fuel: Additional fuel taken at the captain’s discretion to cover expected delays, runway changes, weather deviations, or any other operational considerations.

Has a plane ever run out of fuel?

While extremely rare, there have been instances where planes ran out of fuel mid-flight — often due to a combination of human error and unusual circumstances. Two of the most famous cases are:

✈️ The Gimli Glider (Air Canada Flight 143, 1983)

This Boeing 767 ran out of fuel at 41,000 feet over Manitoba due to a metric conversion error. The fuel had been loaded using pounds instead of kilograms — resulting in less than half the needed fuel being onboard. The pilots glided the powerless aircraft to a former air force base in Gimli, Manitoba. Miraculously, no one was seriously injured.

Why it happened:
Fuel quantity was calculated incorrectly due to confusion between metric and imperial units (kilograms vs pounds).

✈️ The Azores Glider (Air Transat Flight 236, 2001)

On a flight from Toronto to Lisbon, this Airbus A330 experienced a fuel leak due to improper maintenance. The pilots were unaware until it was too late. The aircraft ran out of fuel over the Atlantic Ocean but glided over 75 miles to safely land in the Azores. All 306 people survived.

Why it happened:
A fuel line had been damaged during maintenance, causing a leak that went undetected until both engines failed.

These events led to improved training, better fuel monitoring systems, and procedural changes — making commercial aviation even safer today. There's way more chance of you winning the lottery than being on a plane that runs out of fuel.

If you have any questions pop them in the comment section below and if you haven't tried our Jumbo Jet Espresso out yet, you're missing out!

Nathan Raab
Airline Pilot | Better Coffee Advocate | Jet Bean Founder