More than 500 BA flights had to be cancelled on Thursday after 1,000 ground staff walked out in support of sacked workers at the airline’s catering supplier.
A flight to Paris, one of 31 departures BA pledged to operate, took off just before 9:00 pm (2000 GMT) on Friday evening.
Hordes of other passengers were left behind, queuing for food, drink and blankets at makeshift snack corners set up in the airport’s departure lounges.
Other restored destinations were Munich, Frankfurt, Edinburgh, Hamburg, Manchester, Hong Kong, Johannesburg, Singapore, Melbourne, Dubai, Rio de Janeiro, Sydney, Bangkok, and Tel Aviv.
The company’s staff in the Transport and General Workers Union (TGWU) started to return to work on Friday after a walkout in support of sacked employees of Gate Gourmet, BA’s catering supplier at Heathrow.
But there was still a massive backlog of flights left over from the previous day at Europe’s busiest airport.
“We face a complex logistical challenge with at least 100 aircraft and 1,000 flying crew out of position,” Mike Street, director of customer services and operations, said in a statement.
“As a result, it will take some time to return to a normal flying program,” he said.
The breakthrough followed an agreement by managers from Gate Gourmet to meet officials from the TGWU to try to resolve the sackings row.
Across Heathrow departure lounges, thousands of passengers continued an unbroken vigil for alternative travel arrangements.
“It’s going to take an awful long time to get things back to normal,” a BA customer services official said. “There are planes still on the tarmac which need to be unloaded, and food on board that needs to be dealt with, and that’s going to take a long time.”
Henk Potts, an analyst at Barclays Stockbrokers, said the dispute could cost BA ₤10 million (A$23.5m) a day, at a time when it is grappling with soaring fuel prices.
Qantas, Finnair and Sri Lankan Airways, which use the same baggage handlers, also felt the blow.
But on Saturday Qantas flights from Australia to London were operating normally, the Australian carrier said.
Qantas flights to London were scheduled to leave on schedule, except for QF29 Sydney-Hong Kong-London, which was delayed until 2205 (AEST), a spokesperson said.