Hero 'Thor' returns to hammer NSW skies

With a high-risk bushfire season forecast for the summer across NSW, a much-loved hero has flown back into town.

The Hercules C-130, nicknamed 'Thor', has returned to the RAAF Base at Richmond in Sydney's northwest to again provide assistance to NSW firefighters from the skies.

The mammoth aircraft, capable of dumping 15,000 litres of water or fire retardant at a time, has been busy in the northern hemisphere summer.

"With record dry and warm conditions over the past two months and a forecast of similar conditions leading into spring, these aircraft are an important asset in our firefighting toolbox," Deputy RFS Commissioner Rob Rogers said in a statement on Friday.

The NSW government has allocated $38 million for the use of Thor and another air tanker over the next four years, along with 100 other firefighting aircraft across the state.