A striking triangular postage-due stamp from the Republic of Congo, featuring a vintage single-engine aircraft set against a finely engraved sky backdrop. Issued in the 1960s, this Timbre Taxe denomination of 0.50 franc showcases detailed linework by designers R. Serres and P. Forget, typical of early post-independence Congolese issues. The unusual triangular format adds strong visual appeal, making it a desirable addition for collectors of African postal history, aviation themes, and revenue/postage-due material. Clean impression and rich colors enhance its display value.