International passenger traffic slumped 2.4 per cent in April as flight cancellations due to a volcanic ash cloud from Iceland slammed the brakes on recovery, airline association IATA said Thursday.
"The ash crisis knocked back the global recovery -- impacting carriers in all regions," said Giovanni Bisignani, director general of the International Air Transport Association.
"Last month, we were within one per cent of pre-crisis traffic levels in 2008. In April, that was pushed back to seven per cent," he said.
European carriers bore the brunt of the disruption from the volcanic ash cloud, with traffic dropping 11.7 per cent in April.
Bisignani said this "could not have come at a worse time" for the region.
"Europe's slow recovery from the global financial crisis and its currency crisis are already a huge burden on the profitability of its airlines," he noted.
"The uncoordinated and excessive cancellations and unfairly onerous passenger care requirements rubbed salt into the European industry's wounds," said Bisignani, reiterating his criticism of the way European governments had handled the ash cloud crisis.
The impact was felt beyond Europe, with North American carriers reporting a 1.9 per cent decline in April as north Atlantic routes were also hit. This marked a sharp drop from the 7.8 per cent growth posted for March.
Asia-Pacific airlines saw their traffic growth slow to 3.5 per cent from 12.9 per cent in March.
Middle Eastern carriers reported growth of 13 per cent, African carriers' traffic was up 8.6 per cent while Latin American airlines recorded an increase of 1.2 per cent. All were significantly slower growth than in March.
Cargo traffic suffered less, with growth slowing to 25.2 per cent from 28.1 per cent in March.
"The ash crisis was a shock. While there is always a danger of the consequences of renewed volcanic eruptions, the impact on passenger confidence should be limited," Bisignani said.
"Unfortunately, we are trading ash for two additional uncertainties -- strikes and a growing currency crisis -- both of which are also focused on Europe," he added.
He stressed that it was the wrong time for employees to ask for pay hikes or improved conditions, describing such demands as a "divorced from reality."