Q&A: How long will chaos last – and what has it cost?

Q When is the Icelandic volcano chaos likely to end, and when is air traffic likely to resume?

Q When is the Icelandic volcano chaos likely to end, and when is air traffic likely to resume?

A Perhaps not before mid-week, or even later. All UK flights are grounded until at least this evening, and some airlines have already cancelled all today's flights. But the situation may not improve before Wednesday at the earliest, because the situation depends on the amount of volcanic ash coming from the eruption of the volcano, Eyjafjallajoekull, and the strength and direction of the wind.

Q What's happening with the volcano?

A Yesterday, Icelandic scientists said the eruption appeared to have quietened slightly, with the ash plume diminishing, which is potentially good news, because the lower the ash, the less far it travels. But the respite may only be temporary: the last major eruption of Eyjafjallajoekull lasted intermittently from 1821 to 1823. And even if it does slacken, there is an enormous quantity of ash already in the atmosphere over Britain, scattered in a very complex way. It is lower over southern England, and high over northern Scotland.

Q What's happening with the wind?

A Unfortunately, it is blowing the ash straight towards us. There is a high-pressure system over the eastern Atlantic (giving us our fine spring weather) and this looks unlikely to shift until Friday when winds are expected to move in from the south-west, continuing over the weekend, which might move the cloud north-east away from Britain. In the meantime rain would help, because it would wash the ash out of the atmosphere at lower levels, but there is very little prospect of rain in the present weather system.

Q What effect is the ban on UK flights having?

A The most immediate concern is that thousands of Britons are still stuck abroad. The children of the Liberal Democrat leader Nick Clegg, for example, are stuck in central Spain on a visit to the family of their mother, who is Spanish. The Ministry of Defence is considering flying troops wounded in Afghanistan to coalition partner countries such as Germany for treatment if UK airspace remains closed. The ash cloud has also affected troops returning from Afghanistan: an RAF transport plane flying hundreds of soldiers from 11 Light Brigade at the end of their tour of duty had to land in Cyprus, and the RAF is working on ways to get them back to Britain.

Q What about the effect on the economy?

A The flight shutdown has so far cost the European travel industry more than £1bn in cancelled flights, lost hotel rooms and empty cruise liners, said the crisis advisory company, Lewis PR. "Airlines alone are facing a massive bill from lost revenues and the enormous costs of re-accommodating and repatriating stranded passengers," said the company's Paul Charles, a former senior director at Virgin Atlantic. The Dubai-based airline Emirates, which is providing accommodation and meals for 6,000 passengers, said the disruption had already cost it $50m. Yesterday, airline pilots called for a banking-style rescue of the airline industry. "The short-term financial impact could not be more serious for an industry already reeling from the economic downturn," said The British Airline Pilots' Association. City pundits said the eruption was unlikely to derail a fragile recovery, unless the impact lasted for weeks. Howard Archer, chief economist at IHS Global Insight, said: "The overall economic impact should be limited even if the problem persists for several more days."

Q Is the total air shutdown over Europe really necessary?

A Two bodies representing most of Europe's airlines and airports questioned the extent of the flight restrictions and called for an immediate reassessment. The two airline bodies, ACI Europe and AEA, said: "The eruption of the Icelandic volcano is not an unprecedented event and the procedures applied in other parts of the world for volcanic eruptions do not appear to require the kind of restrictions that are presently being imposed in Europe." Some airlines, including the Dutch carrier KLM, Germany's two biggest airlines Lufthansa and Air Berlin, and Air France, made test flights over the weekend without mishap. Last night, BA made its own test flight from Heathrow in a Boeing 747. The aircraft flew over Windsor and Reading and headed over the Atlantic before landing in Cardiff after about three hours.

Q What about this week's big European football games?

A Uefa have confirmed that both Champions League semi-finals will go ahead. Barcelona will travel by coach to Milan to face Inter on Tuesday. Olympique Lyonnais will travel to Bayern Munich 24 hours later. A decision will be made shortly regarding Thursday's Uefa Europa League matches, with Liverpool are away at Atletico Madrid, while Fulham are to travel to Hamburg.

Q How have Britain's schools been affected by the ash cloud?

A For most schools today is the first day back after the Easter break, but hundreds of teachers remain stranded abroad. There were warnings last night that some secondary schools might be forced to cancel lessons for younger pupils to allow those teachers present to concentrate on pupils who have exams coming up.