Operators are concerned that disruptions to the supply chain created by the six-day closure of European airspace, following the Icelandic volcanic eruption, could run into May.
Fears are now growing that backlogs of freight arriving in the UK will build up in warehouses around airports, with HM Revenue & Customs having to clear six days' worth of inbound air freight as volumes return to normal.
Charlie Fulk, MD at Goldstar Heathrow, believes things could get interesting: "As goods wait to clear Customs, we could see planes not moving because they cannot unload freight because warehouses are too full."
But he adds the situation is improving: "Freight is slowly filtering through. We had a 15% uplift through the night [between Wednesday and Thursday] and all of the staff will be back in on Thursday night, but we are looking at 60% to 70% of what normally goes through."
Goldstar Heathrow is also routing trucks into Europe, running to Madrid and Amsterdam, to keep freight moving.
Martin Carroll, chairman of Saints Transport, expects it will take up to two weeks to clear the backlog of freight that has built-up in warehouses across Europe.
"It has been a very busy time for us. We have sent nearly 50 trucks into Europe and that has really made up for any shortfall we might have had. As a result, that means the impact has been quite small on us.
"If the situation had gone on any longer, we would have routed back to road freight. We have loads going to Luxemborg, Germany, France, you name it, and they are all coming back full."
Peter Quantrill, director general of the British International Freight Association, confirms that there has been modal shift in Europe, but adds that freight coming from long-haul routes - such as Asia - will continue to be affected the most.
He stresses the need for operators and freight forwarders to maintain close dialogues with customers over the backlogs and re-routing of freight movements.
A Kuehne + Nagel spokeswoman confirms that this approach is already being adopted. "We are working closely with customers to seek alternative routing of goods and are offering solutions via road where possible."
But she was unable to confirm what percentage of goods were being moved by road as opposed to air as a direct result of the crisis. The company says that some 70%- 80% of European air freight flights are now back to usual.
The FTA has warned that re-routing European air freight by road could be affected by bans on weekend lorry movements in countries throughout Europe and has called on governments to negotiate temporary alleviations of the restrictions.
