The price of a high-altitude toilet flush? One litre of fuel, according to a pilot with China Southern Airlines.
As Chinese airlines come under increasing pressure from fuel expenditure, China Southern's latest strategy is to encourage passengers to spend their pennies before boarding the aircraft.
"The energy used in one flush is enough for an economical car to run at least 10 kilometers," Captain Liu Zhiyuan, who flies regularly between Hangzhou and Beijing, told Xinhua on Wednesday.
Citing a survey by the company's logistics department, Liu said carrying one kilogram of items such as blankets and pillows by air for one hour uses 0.2 kilograms of fuel oil.
"This means the blankets and pillows on board the aircraft eat up 60 tons of fuel every day. If each seat is loaded with three 450-gram magazines, another 60 tons will be consumed," he explained.
"One hundred and twenty tons of fuel can carry a Boeing 737 aircraft to Paris from Beijing and back," he added.
"Fuel expenditure accounts for up to 35 to 40 percent of the total operational costs of Chinese airlines, so reducing fuel consumption to the extent that the basic needs of customers are still guaranteed has become essential," he said.
Another cost-saving technique has been implemented that will keep 47 million yuan a year in the airline's coffers. The company has asked logistics staff to fill the water tank only 60-percent full..
Liu Zhiyuan said that pilots could also save money by maximizing their flying skills. "Wind velocity varies at different heights so fuel consumption also differs," he said.
In the first half of the year, the aggregated loss of China's local airlines was estimated at around 3 billion yuan. To offset the rising costs of fuel, the Chinese government has allowed the civil aviation industry to raise fuel surcharges twice this year.