On Tuesday the Commercial Aviation Association of South Africa (Caasa) released its composite index of aviation activity for the fourth quarter of last year (4Q17). The Caasa Aviation Activity Index (CAAI) is created using 25 different indicators. It is designed to provide a measure of economic activity in the commercial aviation industry that is balanced and objective. Because buying and selling aircraft creates short-term volatility, due to the small numbers but high prices involved, the CAAI incorporates a trend based on a three-month moving average. Six key overall trends have been identified. The first, as listed by Caasa, is that the value of the index rose a little during 4Q17 to 115.6. This represents an increase of 15.6% over the CAAI base period of 1Q14.