Meet Dr Alisdair Clark

How did you get into aviation and aviation fuelling?

As a boy I used to watch a local biplane perform aerobatics over my back garden and was transfixed. I was also an avid model plane builder. Following my Chemistry degree and PhD, I joined BP in 1988 in the automotive fuels division and transitioned to Air BP in 1993. 

I’m now responsible for Air BP’s Aviation Fuels Research and Development Programme. This involves progressing aviation fuel technology within BP, liaising with manufacturing refineries, distribution transport, storage and into-plane supply. I also sit on the Steering Committee for the Co-ordinating Research Council for Aviation, which is considered to be the top aviation research group in the world. It comprises experts from across the engine, airframe, regulator and fuels industries. I also continue to represent the company at international level at ASTM and Defence Standard aviation fuel specifications.

What attracted you to Air BP?

Air BP is one of the few companies that knows aviation from refinery to wingtip, including combustion and environmental issues. The company is able to balance the commercial reality of operating in a growth industry with technical excellence, environmental aspiration and positive working relationships around the globe. People make a company, and Air BP has great people.

Dr Alisdair Clark, manager of Air BP’s Aviation Fuels Research and Development Programme, is based at our Sunbury headquarters in the UK.

How is jet fuel made?

The majority of jet fuel in the world is made from a particular distillation fraction from crude oil.  In addition, there are routes to synthesise jet fuel from coal, natural gas, bio-mass, vegetable oils and alcohols. The synthetic routes will become more important in the long-term to manage CO2 emissions.

How do you control the quality?

Specifications have been developed specifically for aviation fuels since 1917. Their role is to ensure the reliability and safety of flight and they contain tests for the product using industry-defined test methods together with other detailed requirements such as approved additives. Air BP’s aspiration is not only to meet the specification, but also the ‘spirit of the specification’ – to provide a good quality, fit-for-purpose aviation fuel for aircraft use.

What’s the difference between Avgas and Jet fuel?

Avgas is a high-performance gasoline for spark ignition piston aviation engines. For commercial aviation use, the requirements are more severe than for automotive fuels.  Avgas burns within the engine on an ‘intermittent’ basis. Jet fuel, on the other hand, is used for aviation turbine engines and burns under steady state conditions. 

There is also a significant safety difference between the fuels – when Avgas is spilt, the vapour is immediately flammable. Jet fuel has to be heated to at least 38˚C before the vapour will catch fire.

What does a higher quality fuel do for a customer/plane?

Both Avgas and Jet fuel are high quality fuels and have allowed aviation engines to far exceed ground fuels use. A reliable performance Avgas engine can regularly deliver 300 HP with some designs easily capable of >1000 HP.  However, a jet engine, which can operate for up to 11 million miles before overhaul, can provide (at 400 mph) >90,000 HP. This is why Jet fuel rules the commercial sky.

What’s happening in aviation fuel at the moment that is exciting?

International Air Transport Association (IATA) figures showed a jump of 6.3% in global demand for air transport in 2016. This is phenomenal, but now fuel supply has to keep pace – such a demand for product places new and exciting demands on Air BP research and development activities.

Aircraft fuel efficiency is improving at over 1.5% each year, which helps manage the environmental foot-print together with the introduction of sustainable fuel options. For example, the recently announced agreement between Air BP and Fulcrum turns municipal waste into Jet fuel.

What does that mean for the industry?

A key document for the industry is the 1944 Chicago Convention on International Civil Aviation. This broadly sets out how the aviation industry operates today on a global scale.  The appetite to travel and the need to balance the environmental impact is becoming the most significant challenge of our time.  The industry is built on technology, to ensure the reliability and safety of flight, and will look to technology to ensure a sustainable future for the generations to come.

Will the aviation industry ever abandon Jet fuel for another fuel type?

For long-range commercial flights, this looks very unlikely. All approved synthetic/renewable aviation turbine engine fuels are designed to have the same properties as current production fuel. The industry has tried other fuel types, for example natural gas and hydrogen – these do work but carry other hazards compromising flight safety.

Having said that, for light aircraft undertaking shorter journeys, electrical aircraft may end up being viable – it’s a possibility already being explored by the likes of Airbus and others.