Massive fire-fighting aircraft battle Californian blaze

Jumbo jets are usually used to fly passengers thousands of kilometres around the world, but in California they're being used for something far more dramatic.

Large aircraft including a reconfigured Boeing 747 are being used to help fight large bush fires, which are frequently sparked during California's dry season.

Built with massive water tanks on-board, some of the planes can drop as much as 71,000 litres of fire retardant in one go.

So far this year, Californian fire authorities have used nearly 8 million litres of retardant fighting fires.

The 747 supertanker can cover a huge area in a single run - it can drop retardant across an area 5km long, at the width of a rugby field.

It's fast as well. It takes just 45 minutes for the aircraft to fly from the fire ground to a refuelling airport in Sacramento, more than 600km away.

The airport in Sacramento has been strategically placed between northern and southern California, allowing it to be dispatched to any fire in the state as fast as possible.