In 2018, revenue streams finally reached their 2011 peak of 111.3 billion U.S. dollars. However, it is predicted revenue streams will fall by 2020 to 101.2 billion U.S. dollars.

Air cargo

The air cargo industry includes companies that transport property in an aircraft for a fee. Cargo can be transported on an aircraft designed only for cargo, on a combination aircraft with separate areas for passengers and cargo, or through using any spare space on a passenger aircraft. Because aircraft often transport passengers and cargo, the air cargo sector is considered part of the broader commercial aviation industry. As a result, some cargo-only airlines such as FedEx are among the largest commercial airlines.

Inconsistent growth

The somewhat erratic revenue generated by the cargo segment contrasts to the more consistent growth seen in the overall global commercial aviation industry. Part of this may be due to the variable cost of airline fuel affecting the feasibility of sending cargo by air compared to other methods. This hypothesis seems to be supported by the decline in non-regular air cargo services following periods of high fuel prices, and the faster growth of regular air cargo services when fuel prices are low.