Weakening economic conditions worldwide affected air traffic during May, according to a new report from the International Air Transport Association (IATA).
Global passenger traffic growth remained flat in May 2012, compared to April, although there was a 4.5% rise in year-on-year passenger traffic during the month.
Apart from the Middle East, almost all regions reported sluggish growth in passenger demand in comparison to previous months.
Freight traffic in May declined 1.9% over the previous year's results and 0.4% below the freight volume recorded in April, while the freight load factor remained unchanged at 45.3% from April, but declined 1.2% when compared to May 2011.
IATA director general and CEO Tony Tyler said the airline industry is fragile.
"Relief in oil prices provides some good news. Unfortunately, the softness in oil markets comes on the back of fears of deterioration in the European economy," Tyler said.
"Airlines are expected to return a $3 billion profit in 2012 on $631 billion in revenues. That's a razor-thin 0.5% margin."
According to IATA, international passenger demand increased 5.6% during May 2012, compared to 2011, a drop from the 7.1% growth recorded in April 2012.
IATA said that the 4.1% capacity expansion had supported improving load factors from 75.9% in May 2011 to 77% May 2012.
Domestic passenger demand increased 2.7% during the period, less than the 4.1% rise recorded in April, while load factors also declined to 78.8%, in comparison to 79.6% in May 2011.
Japan reported the highest growth with a 14.8% rise in domestic passenger traffic, followed by a 7.2% rise in Brazil, 4.4% rise in China and 0.1% in India, while domestic passenger traffic in the US declined 0.1% during the month.
"Whether bringing people together or moving cargo around the globe, aviation is vital to modern life," Tyler said.
"Now we need governments to move from recognition to action with tax policies that don't kill growth, regulation that enables growth and infrastructure to accommodate growth."