In a bid to adopt more efficient and sustainable processes, Singapore Airlines (SIA) has begun operating what it calls "green package" flights on its non-stop San Francisco-Singapore route, powered by sustainable biofuels produced from used cooking oils and conventional jet fuel. The flights - the first of which took off on May 1 - also use SIA's most fuel-efficient aircraft and optimized flight operations and air-traffic management systems which reduce fuel burn and carbon emissions. SIA's CEO, Goh Choon Phong, says the initiative is meant to help promote the use of sustainable biofuel in "an operationally and commercially-viable manner," while improving the efficiency of its operations. The fuel is produced by AltAir Fuels and supplied by SkyNRG in cooperation with North American Fuel Corporation, a wholly owned subsidiary of China Aviation Oil (CAO), and EPIC Fuels.