All of Scotland's airports were closed from Thursday until Friday evening
Restrictions on flights from Scottish airports, put in place after a cloud of volcano ash drifted across the UK, have been lifted.
National Air Traffic Services said a large part of airspace had reopened but passengers were advised to check with their airline before going to airports.
Some trans-Atlantic flights may resume now that the restrictions are lifted.
However, Ryanair has announced all its flights to and from the UK have been cancelled until 1300 BST on Monday.
All of Scotland's airports were closed from Thursday morning until 1900 BST on Friday, with only a tiny number of flights running to and from the country.
However, Nats said the cloud of ash from the Eyjafjallajoekull eruption in Iceland has been moving away from Scottish airspace.
A spokesman said: "The cloud of volcanic ash continues to move south through the UK and the eruption in Iceland continues.
"Following a review of the latest Met Office information, Nats advises that restrictions preventing flights in controlled airspace over England and Wales will remain in place until 0700 BST on Saturday 17 April, at the earliest.
"From 1900 BST today, air traffic control restrictions will be lifted in a large part of Scottish airspace including Scottish airports, Shetland, Orkneys and also Northern Ireland."
However, flights into the rest of UK airspace and into parts of Europe still face restrictions.
Earlier on Friday, an Air Transat flight to Toronto took off from Glasgow Airport.
Check-in desks at Glasgow Airport have been empty for most of the day
A small number of flights from North America into Belfast, Prestwick and Glasgow airports were also allowed to land overnight and on Friday morning.
Other services have also been allowed from Glasgow and Prestwick to Belfast and the Western Isles, as the ash cloud moved away from the west coast.
Three flights from the Dominican Republic, Mexico and Orlando in Florida landed at Glasgow airport on Friday morning, after they were diverted from Gatwick.
Two flights from Iceland also landed at Glasgow, bringing with them hundreds of stranded tourists.
Among them, was a school group from Loughborough in Leicestershire.
One of the teachers had photographs of the plume of ash breaking through the clouds as they flew back to Scotland.
'Dust on cars'
Loganair said a limited number of flights, including those between Glasgow and Stornoway, Islay, Benbecula and Barra, started operating on Friday afternoon following advice that flight routes used by these services were clear of volcanic ash.
The first flight saw 16 passengers leave Glasgow for Stornoway at 1410 BST.
The airline said it hoped services would return to normal on Saturday.
Flybe also hoped to operate flights from Glasgow to Belfast City.
The ash, which has been examined by scientists, is said to be non-toxic
The Scottish Environment Protection Agency said it was examining particles of the ash that had been found in Scotland.
But First Minister Alex Salmond told the BBC: "It's not toxic or poisonous, it's not radioactive and shouldn't pose any danger to general health".
Peter Sloss from the Met Office said people could start to see dust on their cars by Saturday.
"As the winds begin to ease down the heavier particles start to fall," he said. "We'll also find heavier rain coming into the north of Scotland tonight and into Saturday morning.
"The rain itself will start to wash some of the particles down so we could well see dust on cars."