International air traffic in 2009 suffered its worst decline in demand since the Great Depression, an industry association said Wednesday.

In terms of demand, the airline industry had its worst year ever in 2009, the International Air Transport Association says. (Amy Sancetta/Associated Press)

Amid the worst financial crisis in generations, passenger demand dropped 3.5 per cent while scheduled carriers flew 75.6 per cent full, the International Air Transport Association said Wednesday.

Cargo demand suffered an even bigger hit, falling 10.1 per cent, with an average load factor of 49.1 per cent.

"In terms of demand, 2009 goes into the history books as the worst year the industry has ever seen," said Giovanni Bisignani, the director general of the association.

The airline industry has lost 2.5 years of growth in the passenger market and 3.5 years in the freight business, he said. The situation started to improve in recent months, but the association expects international carriers will lose $5.6 billion US in 2010.

International passenger demand increased by 4.5 per cent in December and planes flew 77.6 per cent full as capacity fell 0.7 per cent.

December's demand marked an 8.4 per cent improvement from the February low point, but was still 3.4 per cent below the early 2008 peak.

Revenues per passenger mile flown have started to improve following capacity reductions, but they remained five to 10 per cent below 2008 levels.

Seasonally adjusted demand figures for December increased 1.6 per cent from November, while freight demand was almost flat.

Security costs

In 2009, carriers in North America, Asia-Pacific and Europe recorded the largest year-over-year declines in passenger demand of 5.6, 5.0 and 5.6 per cent, respectively.

North American carriers declined by 0.4 per cent, while European carriers decreased 1.2 per cent in December.

The industry also faces a renewed security challenge from the attempted Christmas Day bombing of a Detroit-bound airline.

Bisignani described the Obama administration's approach to security as encouraging but said airlines spend $5.9 billion US annually for what is essentially national security.