Qatar Airways has made a major breakthrough in airline fuel technology by operating the inaugural paying-passenger flight powered by natural gas, with a flight between Gatwick and Doha on Monday. The move is regarded as an important step in the industry’s attempts to reduce its dependence on oil-based fuel.

The airline contacted passengers booked for the six-hour flight from London Gatwick to Doha beforehand and offered them a free alternative flight in case they were worried about taking the flight.

The fuel was developed by Shell and uses a 50-50 blend of synthetic gas-to-liquids (GTL) kerosene and conventional oil-based kerosene.

Neither Shell nor other members of the development consortium claim it is better at reducing carbon emissions, saying only that “there may be some modest CO2 emissions benefits”.

Jeff Gazzard, board member of the Aviation Environment Federation group, told The Financial Times: “GTL is useful for local airport air quality but has a higher carbon footprint than ordinary fuel.”

A number of manufacturers and airlines, including Continental Airlines, Virgin Atlantic and Air New Zealand have been testing alternative fuels based on substances ranging from algae to coconut oil.

Last February, Virgin Atlantic flew a Boeing 747-400 trip with one engine operating on a 20 per cent biofuel mix of babassu oil and coconut oil.

Airbus flew an A380 last year with one engine powered by GTL fuel.

However, Qatar Airways claims to be the first airline to use GTL kerosene on an ordinary scheduled flight with paying passengers.

A spokesman for the Civil Aviation Authority in the UK said GTL had been used on military flights but the Qatar flight was the first time the authority had heard of it being used on a commercial flight with passengers.