Collectively, the region's airlines carried an aggregate total of 25.6 million international passengers for the month, representing a 5.3% increase compared to the same month last year.
Reflecting solid growth in long-haul travel markets, demand as measured in revenue passenger kilometres (RPK) grew by 9.2%.
The growth in demand, coupled with a 6.2% expansion in available seat capacity, led to a 2.3% increase in the average international passenger load factor to a high of 80.4% for the month.
On the back of strong international demand, business conditions continued to improve across Asian economies, in turn lending support to international trade activity, says AAPA.
This helped underpin further growth in air cargo volumes in April, with demand in freight tonne kilometre (FTK) terms registering a 9% increase compared to the same month last year.
Offered freight capacity grew more modestly, by 2.8% for the month. As a result, the average international freight load factor increased by 3.7% to reach 65.1%.
AAPA's director general, Andrew Herdman, says: "The broad-based expansion in global economic activity, coupled with renewed demand on selected routes, particularly between Europe and Asia, has contributed to growth in long-haul travel markets in recent months, whilst regional travel markets remain strong supported by a combination of competitive air fares and expansion in the region's economies.
"Overall, during the first four months of the year, Asian carriers registered a 5.2% increase in the number of international passengers carried to an aggregate total of 103 million.
Within the same period, Asian airlines recorded a solid 9.5% increase in air cargo demand, supported by a pick-up in export orders across the region's economies."
Looking ahead, Herdman notes: "Business and consumer confidence indicators remain positive and underpin expectations of continued growth in air passenger and cargo markets in the coming months.
However, the impact of rising fuel and staff costs are a concern, particularly as airfares have remained low in an intensely competitive environment.
"Nevertheless, Asian airlines remain proactive in reviewing their operations, implementing cost-cutting measures and streamlining business processes, with the aim of improving efficiency and sustaining profitability."