Iceland's Grimsvötn volcano continues to erupt, and the ash cloud has delayed or cancelled UK flights, with Scottish airspace virtually shut down and some airports closed.
The Volcanic Ash Advisory Centre predicts that the ash cloud will cover most of the UK by 1200 GMT on Tuesday (2200 Tuesday Sydney time) -- which will likely delay flights further.
The "FL200" on the map at the top of the article means that the ash is expected to reach 20,000 feet -- making landing at UK airports problematic.
Travellers with plans to reach the UK should start considering other options in the event that the rest of UK airspace closes down, as it did last April for the Eyjafjallajökull volcanic eruption.
Check with your airline for their current plans, and ask specifically about their plans in the event that your flight from an Asian or US hub to London is cancelled. Last year, many travellers took advantage of global airline alliances and flew into unaffected Spain on Iberia, the oneworld partner of Qantas and British Airways.
How to get to Scotland with airspace closed
Travellers for Scotland who had been planning to fly into the country will need to change in London, Manchester or Birmingham to the train.
Manchester is furthest north of the three larger airports, with a train station inside the airport with direct trains to Scotland. It's probably the best choice of the three.
Birmingham is another good choice, as the UK's West Coast Main Line (which runs Virgin Trains) has a station inside the airport, although you'll need to change in the cavernous and depressing 1960s-era Birmingham New Street station for Scotland trains.
Connecting to the train via London is more complex. From Heathrow, you'll need to get to Euston for Glasgow trains or King's Cross for Edinburgh trains. Euston is a pain to get to (our recommendation is to take the Heathrow Express to Paddington and then take a taxi), but King's Cross is on the Piccadilly Line Tube -- which runs from Heathrow.
If your plane arrives in the evening, you have an option to take the Scotrail Caledonian Sleeper from Euston, which runs two trains every night except Saturdays to Aberdeen, Edinburgh, Fort William, Glasgow and Inverness. The Glasgow and Edinburgh train is the last to depart at 2300.
How to get to the UK when airspace closes
In the immediate future (while the cloud is expected to cover only the UK) the best option is likely to be to aim for Paris or Brussels by air and then continue onwards to the UK by the high-speed Eurostar train through the Channel Tunnel.
If Paris and Brussels are affected (as seems likely), German airports Frankfurt and Munich are likely to be good alternative options (Frankfurt is closer to London than Munich). From there, the Deutsche Bahn trains run quickly to Paris, and from there you can pick up the Eurostar.
As a final resort, Spain is the least likely to be affected. With national carrier Iberia part of the oneworld alliance (and under the same International Airlines Group corporate umbrella as British Airways), flying into Spain will at least get you to Europe. From there, high-speed
AVE trains will take you into France, where you can pick up the French TGV high-speed train network to Paris and on to London on Eurostar.
Last year, some travellers ended up flying into Spanish, Italian, German and French airports, renting cars and driving to the English Channel to take the ferry -- though if it gets to that stage, we'd probably recommend you stay at home.
Check your travel insurance will cover you
Make sure your insurance will cover delays, hotels, rerouting and surface travel -- and get it in writing if you can.
Travellers delayed or inconvenienced due to the ash cloud this week are more likely to be covered, because they could not "reasonably" (which is a favourite term from insurers) have foreseen the ash.
Once a "reasonable" person should have been able to foresee the problem, however, travel insurance is less likely to pay up -- which happened during the Brisbane floods last year.