Most flights in the UK will remain grounded until early Sunday as ash from a volcano in Iceland continues to drift.
Many countries and airlines have grounded fleets amid fears that the ash - a mixture of glass, sand and rock particles - could be catastrophic to aircraft.
BBC News website readers trying to fly in and out of the UK have been explaining how the flight ban is affecting them.
JESSICA CAVANAGH, HO CHI MINH, VIETNAM
Jessica is staying with her mother as she waits to fly back from Vietnam
We've been here for two weeks and were meant to be going home on Friday to Manchester. We knew the flight from Hong Kong had been cancelled, but we didn't realise how long the delays were.
We were hoping to fly to Hong Kong but we were turned away as they said it was even busier there. I was a bit shocked, but luckily we are staying with my mother so we don't have to worry about accommodation.
I teach at St Andrews Methodist Primary School in Salford and was supposed to be back at work on Monday. We have now been told that there are no seats on a flight until 28 April. We've now been put on a waiting list from Tuesday.
We tried looking at different flights such as going through Singapore but they're all the same and booked up.
I have mixed feelings - it's nice as I get to see mum a bit longer and it's sunny here, but it's stressful as I don't know when I'm able to get home and I'm worried about my job.
I feel really guilty that I'm missing school as I teach younger children who need stability and as small an upheaval as possible, but my head teacher has been really understanding.
GEORGE CRAIB, AMSTERDAM
George Craib, who has epilepsy, is trying to get to Aberdeen
The airport closed last night and since the airline has not provided any help with accommodation, I've been forced to get my own hotel accommodation. Plus now that I'm no longer at the airport I no longer have any money for food, phone credit etc.
After much arguing with KLM Air France, I was finally put on standby for tomorrow's flight 08:00 and 10:00 but since then I've found out that all flights to Northern Europe are cancelled.
Of course this leaves me in the predicament, of whether to go to the airport or not tomorrow, then just to complicate matters even further, I've only got enough medication for my epilepsy to last me until tomorrow, so my seizures are likely to start again unless I get access to that.
I realise everyone is in the same boat and there's very little anyone can do about it however needless to say I've been travelling since Wednesday evening now; I'm extremely tired and just want to get home.
MARK ANDERSON, EN ROUTE TO AUSTRIA
I am currently driving to pick my stranded son and friends from Austria who were all there taking a ski instructor course.
My son rang up sounding stressed as his flight was cancelled and he doesn't have a lot of money on him. He has to be at college on Monday and his friends have to go to work so I decided to book the Eurotunnel and go and pick them up.
I set off at half eight this morning and my sat nav says I'll get there at about 11pm tonight - a distance of over 800 miles. I don't mind driving - although I'd rather not be driving 12 hours a day. Driving through Germany at the moment and the view is quite nice.
My son said he'd have a nice pint of beer waiting for me but as I'm driving back tomorrow, I can only have one so I'm looking forward to a nice bottle of red wine on Monday night - and he can pay for it.
MOIRA HICKSON, MOSCOW, RUSSIA
University student Moira Hickson, 21, is stranded in Moscow with her mother. They were flying back to England from Thailand but were grounded on the way to their connecting flight in Moscow.
She told her boyfriend Chris Thurmott, 19, that they are being treated like prisoners and are currently being held under armed guard in a hotel near the airport.
She said everybody who was on the flight, including young children, have been confined to one corridor of a hotel and as they do not have any visas, they are not allowed to leave their hotel rooms apart from when they are escorted by armed guards to the hotel's restaurant for food.
Moira added that the longest they had been outside was 15 minutes when they were allowed onto a balcony. Their luggage remains at the airport and families have been split up.
As they do not speak Russian and no-one there speaks English, they have no idea what is going on although the British Ambassador has been allowed into the hotel.
DEBBIE COLLINS, BRIDGWATER, SOMERSET
Cassy has been stranded at a Moscow airport
My daughter Cassy was on holiday in Dubai visiting her father, her plane home got diverted to Moscow. She has been stuck there ever since.
There is no way to contact Cassy or the friend she is with as their phones have died.
The embassy has said they can't help as Cassy isn't technically in the country but airside, but the airline says it's the responsibility of the airport, the airport says it's the government, they say it's the airline ... And on it goes.
I believe the Foreign Office has sent someone there.
I believe there are 200 Brits airside. Most have been left there with food vouchers. There's no facilities and no access to their luggage. Some - women and kids - have been taken to hotels.
Aeroflot doesn't adhere to the EU guidelines, so they have had little in the way of blankets, food etc.
PHIL APPLEBY, TOKYO, JAPAN
We were due back at Heathrow on Thursday afternoon. Our plane left on time, but five hours into the flight, it was announced that we were returning to Narita Airport.
Since then me, my wife, and our five-year-old daughter have been flitting between hotels and the airport terminal. We've recently checked into our fifth different hotel in five nights. We had seats on a Virgin Atlantic flight that was due to leave today but that has been cancelled.
The good news is that we seem to be guaranteed seats on the first Virgin Atlantic flight out of Narita. The bad news is that we're obliged to stay in the vicinity of the airport, until Heathrow reopens and the flight is confirmed.
It's a reflection of our current state of mind, and the state of things here in Tokyo that the high spot of our day is managing to find a hotel room for the night!
PETE JACKSON, LONDON, ENGLAND
Peter Jackson was supposed to travel to the US with his family
We were supposed to fly out on Thursday. We tried to re-book. We tried calling, and it took forever, and eventually we got through. The earliest they could offer us was Wednesday.
That will most probably be cancelled as well but there's nothing else we can do. We were due to travel to Cincinnati, flying in to Dayton in Ohio.
My wife is American and we try to go twice a year. Her dad's not well. We try and go over for Thanksgiving or Christmas and at Easter as well. He is in a hospice - he's had a stroke and is paralysed. It's good for him to see his grandson.
If the situation is just as bad on Wednesday, we'll have to cancel our trip. It just won't be worth our while going for a couple of days.
COLIN CASKEY, DONCASTER, SOUTH YORKSHIRE
Colin Caskey had to hire a car to get back to the UK
I'm one of the lucky ones who managed to make it home.
Following my flight cancellation in Pisa on Thursday morning I managed to take a different flight from Florence to Paris Thursday evening and landed just before they closed French airspace.
Eurostar was fully booked but I managed to get a train to Calais.
Only P&O seem to allow foot passengers and were fully booked, but you can book onto SeaFrance with a car or bicycle.
I hired a car in Calais and got on the ferry, then drove to Gatwick and dropped off the car.
Final leg was the train back to Doncaster, all that remains is to go and pick up my car from Leeds airport today.
My advice, go to Calais and hire a car, although it is expensive at 600 euros (£526), and this will get you on the ferry.