A light plane trip passing over Walgett may have prevented a structural fire in a hay shed on a local property from spreading any further.

The small Fuji Aero Subaru, being flown by Max Phillips with father Michael in the passenger seat, was travelling between Lightning Ridge and Coonamble on the morning of Tuesday 6 July.

The older Mr Phillips said they first spotted signs of the fire just after 7am, shortly after passing over the township of Walgett.

"We spotted a plume of smoke in the distance which I initially took for some kind of burn off," Mr Phillips said.

"But as we approached closer it was clear that this was a structural fire of what looked to be a large hay shed, with nobody in attendance.

"Friends of ours driving down the Castlereagh Highway at the same time spotted the smoke plume from about 20 kilometres north of Walgett, so it was a good 'un."

According to Mr Phillips, the fire was taking place on the 'Euroka' property, located about 15 kilometres south-south-east of Walgett.

He said Max Phillips, as the pilot, promptly reported the fire to the local flight service located in Brisbane and then flew to the nearby homestead to attempt to alert the owners.

"He circled the property dropping paper notes in the hope that folk on the ground would be alerted - it seemed to have worked as a vehicle promptly headed north to the fire," he said.

The North-West Rural Fire Service (RFS) brigade - which covers this area - apparently became aware of the first at roughly 7.15am due to a report from the property owner.

Acting District Manager Michael Apps said two trucks arrived on the scene as soon as they could, but quickly realised it was too hot for them to handle.

"Approximately 200 bales of hay were alight and it was deemed too hot and too much to handle with water and the machinery we had available," Mr Apps said.

"So (as of 8 July) it's still currently burning - we decided to create a safe break around the hay shed itself which the owner could then self-monitor and extinguish when it had died down enough."

According to Mr Apps, the RFS crews decided to do this when they had determined that no further assets on the property were in danger once the safe break was in place.

He said they currently don't know the cause of the blaze since it was still ongoing but he believed the weather had a part to play.

"It was probably due to the humidity in the air, but we can't ascertain if it was due to the recent rain at this stage," he said.

"There have been a number of house fires in the area recently though - including in Walgett, Lightning Ridge and Coolabah, which is between Nyngan and Bourke.

"We're wanting people to make sure people are mindful in this cold weather of their heating appliances - be sure to turn off your heaters and extinguish all internal wooden fires to ensure everyone is safe."