RPK traffic growth among the 240 airlines represented by IATA rose by 5.9% year-on-year in March, according to the industry group's latest traffic report.
Part of the growth may be related to early Easter celebrations this year, IATA notes, but it says that seasonally adjusted figures still point to rapid expansion.
Global demand expanded at an 8% annualised rate in the six months from October 2012 to March 2013, compared with a 3.5% capacity hike.
Average load factors climbed 1.8 percentage points to reach 80.3%.
Middle Eastern carriers continued to lead the growth, with the region recording 15.6% year-on-year expansion in March. South America saw 11.8% growth while African traffic rose 8.2%.
Other regions saw more muted expansion, with Asia Pacific airlines up 5.4%, European carriers witnessing 3.7% growth, and North American traffic rising 2.4%.
"Strong demand for air travel is consistent with improving business conditions," says IATA chief executive Tony Tyler, though he points to "uneven" growth driven by emerging markets.
"Although oil prices have softened in recent weeks, they remain high against historical averages. In view of this, airlines are responding with a very cautious approach to capacity management."