The Icelandic volcano has cost international aviation $1.7 billion in six days, making it more expensive than the reaction to the September 11 terrorist attacks Iata has claimed.

At the height of the problems from April 17-19, it is believed the lost revenues peaked at $400 million a day as the blanket ban on flying across the UK and much of northern Europe was put into place.

Director general and chief executive for the airline body Giovanni Bisignani said: “Lost revenues now total more than $1.7 billion for airlines alone.

“At the worst, the crisis impacted 29% of global aviation and affected 1.2 million passengers a day. The scale of the crisis eclipsed 9/11 when US airspace was closed for three days.

“For an industry that lost $9.4 billion last year and was forecast to lose a further $2.8 billion in 2010, this crisis is devastating. It is hitting hardest where the carriers are in the most difficult financial situation.

“Europe’s carriers were already expected to lose $2.2 billion this year – the largest in the industry.”

Bisignani admitted there have been some savings as a result of the grounding, the fuel bill for airlines affected by the crisis would have dropped by $110 million a day.

He is now demanding governments step in with four specific requests for regulatory relief.

He urged airports to relax slot rules to allow runway space to be maximised while he demanded governments lift restraints on night flights to allow as many flights as possible to return home.

Bisignani also said the European commission should assist with the cost of paying for stranded passengers’ hotel and food bills which are currently the airlines’ responsibility while demanding governments consider compensating airlines for lost revenues.

He said following the September 11 attacks, the US government compensated airlines with $5 billion having been grounded for three days.

“I am the first one to say that this industry does not want or need bailouts but this crisis is not the result of running our business badly,” Bisignani said.

“It is an extraordinary situation exaggerated with a poor decision-making process by national governments. The airlines could not do business normally. Governments should help carriers recover the cost of this disruption.”