Airbus forecast in July that $1.8 trillion will be spent on commercial aviation maintenance, repair and overhaul (MRO) activities over the next 20 years as part of a projected $3 trillion spend on global aftermarket services. In its first Global Services Forecast, which was released at the Farnborough Air Show, the airframe manufacturer said that on an annual basis, MRO spending will grow from $53 billion to $132 billion over the forecast period, which works out to average annual growth of 4.6 percent.