The rising price of oil is driving up costs for airlines everywhere
Belgium's Brussels Airlines has announced it is slowing speeds and reducing weight on some of its aircraft in order to reduce fuel costs.
The airline said slowing its planes by about 10km/h would cut its annual fuel bill by 1m euros ($1.6m; £800,000) and add a minute or two to flight times.
The measures will also reduce the airline's emissions of global warming greenhouse gases, a spokesman said.
Oil prices have risen steeply recently, adding hugely to airlines' costs.
Brussels Airlines is looking at nearly 100 ways of cutting fuel use, including more efficient fuel use and reducing weight on its planes.
Harmonised air system
The airline's fleet of 30 Avro aeroplanes, flying short routes within Europe, can be flown at slightly slower speeds, airline spokesman Thierry van Eyll told the BBC.
The remaining 19 planes, flying longer routes to Russia, the Middle East and Africa, fly at pre-set speeds and cannot be slowed down, he said.
Other options to cut down on fuel use and reduce weight are carrying less water, getting rid of built-in stairways on planes and adding angled tips to wings to reduce drag on take-off.
Brussels Airlines is also putting pressure on the EU to adapt a harmonised air system.
The current system often forces planes to fly a zigzag route over Europe as they pass over different countries' airspaces.
This measure alone would result in a significant savings of aviation fuel and therefore produce fewer polluting emissions, Mr van Eyll said.