6-7 September 1958

This World Championship of model-aviation was organised by the FAI (Federation Aeronautique Internationale) and the Aero Club Belge. Both organisations still exist today.

Information received from FAI:

The FAI World Control Line Aeromodelling Championships was held in Belgium in 1958. Class F2A, F2B and F2C were held.

• F2A: 38 competitors
• F2B: 38 competitors
• F2C: 36 competitors

13 nations were represented.

Besides many white covers without any cachet, there are 2 'official types' of philatelic items I have identified about this happening:

Official cover of the happening:

Same cover but with the rarer 7 September cancellation:

Card edited for the happening (r) (publisher ?)