More than 100 pilots from 27 countries have descended on the small city of Benalla in Victoria for the 2017 edition.

The Championships are held every two years with competitors fighting across three classes: 15 metres, 18m and the open class.

An Opening Ceremony was held yesterday before the first day of flying was expected to take place today.

However, no action could take place as conditions were not sufficient for competition with rain forcing the planes to stay grounded.

"It is raining at Benalla today as a trough system sweeps across South Australia, Victoria and New South Wales," read a post on the Championships website.

"So a forced rest day with the hope of flying tomorrow."

Poland's Sebastian Kawa is the reigning FAI world champion in the 15m class while his compatriot, Karol Staryszak, is the defending 18m champion.

Germany’s Michael Sommer is the reigning FAI world champion in the open class.

At the Championships, "tasks" are flown and scored every day.

In a task, pilots must make their way around a pre-determined course, which is different each day depending on the weather, and tag turn-points using a navigation system.

Competitors race against each other to complete the course in the quickest time possible.

It is hoped action will get underway tomorrow.