Paris - Applause, cheers and whoops of joy rang out from Asia to New York to Paris on Tuesday as airplanes gradually took to the skies after five days of being grounded by the drifting volcanic ash that has crippled European air travel.
Only limited flights were allowed to resume on Tuesday, and most of British airspace remained shut down. An international pilots group warned that ash remains a danger and meteorologists say Iceland's still-erupting volcano isn't ready to rest yet, promising more choked airspace and flight delays to come.
Yet in many airport hubs that have been cauldrons of anxiety, anger and sleep deprivation, Tuesday marked a day of weary collective relief.
The boards at Paris' Charles de Gaulle Airport announcing long-distance flights - which had been streaked with red "cancelled" signs for five days - filled up with white "on time" signs on Tuesday and the first commercial flight out since Thursday left for New York's John F Kennedy Airport.
"We were in the hotel having breakfast, and we heard an aircraft take off. Everybody got up and applauded," said Bob Basso of San Diego, who has been staying in a hotel near Charles de Gaulle since his flight on Friday was cancelled.
Screaming from happiness
"There's hope," he said. Basso, 81, and his son have tickets for a flight to Los Angeles later on Tuesday.
At New York's JFK, the first flight from Amsterdam in days arrived on Monday night.
"Everyone was screaming in the airplane from happiness," said passenger Savvas Toumarides, of Cyprus, who missed his sister's New York wedding after getting stranded in Amsterdam last Thursday. He said the worst part was "waiting and waiting and not knowing".
An Associated Press photographer saw one KLM jet taking off from Amsterdam into a colorful sunset, which weather officials said was pinker than normal due to the ash.
Limited flights resumed in Scotland, and Switzerland reopened its entire airspace to regular traffic on Tuesday.
The German airline Lufthansa got a waiver to bring 50 long-haul planes carrying about 15 000 passengers home flying at low altitudes, and the country's overall airspace was to open starting on Tuesday afternoon.
Airports in central Europe and Scandinavia have reopened, and most of southern Europe remained clear, with Spain volunteering to be an emergency hub for overseas travelers trying to get home. Spain piled on extra buses, trains and ferries to handle an expected rush of passengers.
Crammed to capacity
Some flights resumed early on Tuesday from Asia to southern Europe. But Asian airports and airlines remained cautious, and most flights to and from Europe remained cancelled.
Two Japan Airlines flights, the first from Moscow and the second from Rome, landed in Tokyo on Tuesday - the first European flights to arrive in Japan since Friday. Both flights were crammed to capacity.
Patrizia Zotti, from Lecce, Italy, carried her 6-month-old son on her back as she waited to finally board a flight out of Tokyo on Tuesday. She was with her husband last Thursday at the airport but they had separate flights - his left just before European airspace choked up, but hers was 20 minutes later and was cancelled.
While they waited five days for a flight, she said, "My biggest worry was the baby".
She and other passengers around the world, while relieved at getting airborne at last, showed continued concern about the ash. "I've read that the exploratory flights were safe, but I'm still a bit worried," she said.
Australia's Qantas cancelled its Wednesday and Thursday flights from Asia to Frankfurt and London, as well as return flights to Asia, saying the situation was too uncertain to resume flights into Europe.
Truck driver Mike Kelly, 62, and his wife Wendy, 60, of Somerset, England, decided to wait out the ash in Sydney.
Another volcano explosion
They were heading home after a four-week vacation to visit their son in Sydney when the volcano ash cloud shut down most European airports and left them stranded at Singapore's Changi International Airport for five nights.
"We're heading back to Sydney today. We heard there might be another volcano explosion so we'd prefer to wait it out on a beach in Sydney," he said. "I was supposed to be back at work on Monday but there's nothing anyone can do."
The optimism about airport reopenings was tempered by a statement from the British National Air Traffic Service early on Tuesday, which said "the volcanic eruption in Iceland has strengthened and a new ash cloud is spreading south and east towards the UK".
British air traffic controllers kept London's main airports closed on Tuesday. Flights have resumed in Scotland, but in a limited way and only for a handful of domestic flights.
Europe's aviation industry - facing losses of more than $1bn - criticised government handling of the disruption that grounded thousands of flights to and from the continent.
A very real threat to flight safety
But the international pilots' federation said on Tuesday that a return to flight operations in Europe will be possible only if the final decisions are left to the pilots themselves, and are based on safety concerns rather than being economically driven.
Gideon Ewers, spokesperson of the London-based pilots group, says historical evidence of the effects of volcanic ash demonstrates that it presents a very real threat to flight safety.
Ash and grit from volcanic eruptions can sabotage a plane in many ways, stalling engines, blocking fuel nozzles, and plugging the tubes that sense airspeed.