Pilots in British Columbia's war against wildfires can dump up to 19,000 litres of water in a single day, often flying over fiery infernos that span thousands of hectares. It's not a job for the faint of heart.

"It's demanding," pilot Jeff Brown said. "After a 10-hour day, you're tired. No doubt."

The province is experiencing the worst forest fire season in years, and the aerial battle has been the initial line of attack.

Forty air tankers and 245 helicopters lead the ground assaults by dumping fire retardants to slow the spread of fires, and later air drops help cool down hot spots.

One of the toughest challenges, Brown says, is judging the wind.

"You always get drift with your drops. Sometimes if you're right over your spot, you do your drop, it lands 20 or 30 feet away."

Pilots receive wind conditions and drop co-ordinates from the Provincial Air Tanker Centre located in Kamloops. The centre also organizes accommodation, meals and rental cars for pilots.

"We're sitting at over 700 missions, and our average is in the neighbourhood of 400. And we're still in the first part of August," tanker centre manager Jeff Berry said.

As a result, the provincial government's budget for fighting the fires has gone up in smoke. The original estimate was set at $62 million, but that bill has more than doubled to $135.5 million.

The tankers used in B.C. include the Airspray Lockheed Electra, the Conair Convair 580, the Grumman S-2 Firecat and the AT802 Airtractor.

The giant Martin Mars water bombers aren't being used because they've been leased to the state of California by the company that owns them.

For more information on air tankers and the Provincial Air Tanker Centre, see the B.C. Wildfire Management Branch website.

With a report from CTV British Columbia's Jina You