[milhistry]

The meaning of the bullion pilot wings also changed over time.

Originally the bullion with crown on top was worn on Full Dress and Blue Undress, padded silk was worn on Service Dress (drab or light fawn jackets), un-padded silk on various types of working dress and metal on Mess Dress.

When the Second World War started, Full Dress died. Undress and Mess Dress were casualties too, though Mess Dress was revived post war. Undress was only revived by some army units (mainly the traditional part-time regiments) and technically, I suppose by the Navy, although their undress looked completely different.

During the Republican era it seems there were only silk and metal wings at first for Service Dress and Mess Dress respectively. Later plastic and cotton versions appeared
for flying gear and shirt sleeves.

Then in the early 1990s, the types with the lion on top appeared. These resembled the WW2 wings more closely but with "the South African Lion" on top instead of the crown. This lion passant gardant holding a fasces of four rods bound together, was the crest of the South African coat-of-arms at the time. At that stage there were standard wings, silver wings and gold wings. The silver and gold were awarded after various flying hour milestones. IIRC, plain white at graduation from flying school, 2500 hrs for silver and 5000 for gold.