July 29, 2016
If you’re heading somewhere hot and sunny this summer chances are you will be making your way to the nearest airport and boarding a plane to take you to sunnier climes. But have you ever thought about the fuel that is going to propel you through the skies? We can’t say that knowing a bit about jet fuel is going to get you to your destination any quicker, but a few titbits of knowledge may help pass the time at the airport or on the plane itself.
Jet Fuel is most commonly referred to as Jet A1, but its technical name is actually Avtur (Aviation Turbine Fuel). Avtur is designed for use in both turbo-jet and turbo-prop aircraft, which basically accounts for all modern planes of any real size. Avtur can rightfully be mixed up with is standard grade kerosene, because that is what it is, and in the UK at least, this is the grade of fuel that is also used for heating oil in boilers and home-range cooking stoves!
Look at the burning qualities of the three main combustion fuel grades, diesel, kerosene and gasoline and you will understand why kerosene is used for aeroplanes.
Diesel – This has the highest boiling point of the three grades but is also the least flammable. So whilst diesel would easily give off enough energy for propulsion in the air, its lack of flammability would not generate enough initial power to get the plane off the ground.
Gasoline (petrol) - Is highly flammable and easily provides the required acceleratory power for take-off, but its energy pay back is poor and fuel consumption too rapid, meaning a plane would have to carry an inconsistent amount of fuel for even the shortest of journeys.
Kerosene – Is more flammable than diesel which gives it the explosive burning qualities required for take-off, but at the same time more energy efficient than gasoline, which means that less fuel needs to be carried.
Aviation fuel facts
A “standard” 747 in mid-flight will burn approximately 4 litres of fuel every second, which based on a cruising speed of 565 mph, means consumption of 25 litres per mile (giving a fuel economy range of 0.18 miles per gallon!).
A 747 has the capacity to carry a staggering 220,000 litres and this only gives it a distance range of around 8,500 miles - not enough to get to Australia from London non-stop
A 747 with a full tank of fuel, adds an incredible 175 tonnes to the plane’s payload.
Total consumption of jet fuel in the UK is an impressive 15bn litres per annum, but an incredible 55% of this volume goes through Heathrow – that’s over 22m litres per day.
All of Heathrow’s jet fuel comes in by pipeline - either direct from refineries (Immingham, Fawley and Stanlow can all pump product directly into Heathrow’s fuel farm) or via import pipelines from the Thames estuary (over 60% of UK jet fuel is now imported).
Once it arrives at Heathrow, the Avtur is stored in the airport tank- before being further distributed via its 80 miles of pipelines. This incredible underground “hydrant” system runs the length and breadth of the airport and has multiple fuelling points to allow the airport’s mobile bowsers to connect up and fuel planes across the whole Heathrow complex.
It’s hard to believe that all this is going on at the airport and many of us will be too busy choosing our duty free or enjoying a glass of bubbly to think about how the plane gets us to our destinations.