But to understand what the future of fuelling holds we need to look back at where it all began.
The success of the Wright Flyer in 1903 brought to the world an understanding of the principles of controlled flight and the need for engines which offer high power to weight ratio and good reliability. For the first few decades of flight, the fuel used was a low boiling hydrocarbon gasoline commonly used in ground vehicles and obtained by distilling crude oil. The link between engine operation and fuel quality remained unexplored for several years. That is until the First World War, when the need for reliability and high-power output led to the introduction of aviation gasoline (Avgas). This high-quality fuel was, and still is, specifically designed for use in spark ignition piston engines.
Gasoline is rated according to its level of octane. Avgas is designed to be a product of high octane quality to prevent engine damage. Initially developed as an unleaded fuel, a lead additive – Tetra Ethyl Lead (TEL) - was introduced around 80 years ago. TEL has been a vital ingredient in achieving the high octane quality of Avgas. The current grade 100LL (low lead), which was introduced in the 1970s, is still widely available across Air BP’s global network.
The arrival of jet engines in the 1930s and 1940s signalled another challenge for engine designers. Avgas is flammable down to about -40oC, so you could be standing at the north pole with a cup of Avgas, light a match and it will burst into flames. A jet engine doesn’t require fuel that vaporises quite so easily. So, instead of using gasoline engineers turned to a kerosene mix. This first type of jet fuel was known as JP-1.
The big advantage of kerosene is that it can have a low freeze point, so is able to stay liquid down to -47 o C and below. Plus, it can be heated up to 38 o C before it will catch fire. The Jet fuel Air BP uses now is made using pure kerosene and while you are likely to encounter different Jet fuel grades globally, the most widely used specifications are Jet A and Jet A-1.
Environmental pressures to eliminate the use of lead and seek cleaner, greener fuels now face the industry. We introduced unleaded Avgas (UL91) in 2016 and will continue to roll it out at new locations as demand requires. Specifically developed by the aviation industry for flight use UL91 is an approved aviation fuel. It contains no lead or blue dye and is of lower octane quality than Avgas 100LL. As a result, it is only suitable for use in certain aircraft. We will however continue to explore and develop unleaded fuel options to satisfy demand.
Hydrogen has also been considered extensively as a potential aviation turbine fuel. When liquefied, the product offers about three times the energy content by weight when compared to conventional fuels. However, this necessitates significant cooling and introduces additional risks including a wide flammability range. So, unsurprisingly it’s an unlikely fuel candidate for future aircraft use.
It’s the development of sustainable aviation fuel (SAF) that is key to changing the face of the aviation industry. Made from non-palm renewable and sustainable raw materials including used cooking oil, these fuels can reduce the carbon footprint of aviation fuel by an impressive 80% over their full life cycle. Air BP’s commitment to developing and supplying SAF is widely recognised. In recent years we’ve supplied SAF to 15 locations in five countries. And at the end of 2018 we entered into an agreement with Neste, one of the world’s leading renewable products producers, to increase the supply and availability of SAF.
It’s not just the fuel itself that has evolved either. Look back at photos from aviation’s early days and you’ll see pictures of people holding jerry cans of fuel to be poured into an engine. Nowadays we’re expected to fuel a big passenger jet with up to 4,000 litres per minute. And while it might once have been common to use a chamois cloth at the end of the hose to filter fuel, filtration technology has also come a long way, catching trace dirt and water at parts per million level. Air BP’s ability to supply clean, dry fuel is a key part of the fuelling process and it’s something we’re continually investing in.
Plus, with misfuelling one of the biggest risks faced by the industry we introduced Airfield Automation in 2018. The cloud-based technology helps ensure the right fuel goes into the right aircraft while providing real-time data to airline customers. We will continue to roll this technology out across our global network before the end of 2020.
Over the last century, aviation as an industry has gone from learning how to fly, to being able to fly faster, further and with greater loads than ever before. Going forward the challenge is to meet continuing passenger growth in a responsible and sustainable manner. Emerging technologies are reshaping the industry with the push for hybrid and electric aircraft, unmanned aircraft systems, robotics and artificial intelligence all playing a role in aviation’s future. But as engines and aircraft become lighter, quieter, faster and more efficient Air BP’s role ultimately is to continue supplying the industry’s aviation fuel needs safely and reliably. And we’re ready to do just that.