Heathrow passengers will face more disruption and misery on Saturday, the airport warned, as investigators attempt to uncover the cause of a mysterious fire on an Ethiopian Airlines plane on Friday night.
Thousands suffered long delays or cancellations after the plane, one of the troubled Boeing 787 Dreamliners, caught fire while on a remote parking stand shortly after 4.30pm.
And to add to Boeing's already severe headache, in a separate incident Thomson Airways said a Dreamliner flight to Florida had to be diverted back to Manchester on Friday due to a "technical issue".
Heathrow Airport warned that there will be some cancellations and delays to flights, with its website is advising passengers to check the status of their flight with their airline before travelling.
Nobody was on board the Ethiopian Airlines-operated plane at the time of the incident and there were no injuries.
Runways were closed to all flights for an hour and a half while emergency crews dealt with the blaze, which caused diversions and long delays for passengers.
The Air Accidents Investigations Branch, which is part of the Department of Transport, told HuffPost UK that investigations were ongoing but no cause was likely to be determined today.
The US National Transportation Safety Board said it was sending a representative to London to assist authorities with their investigation into the fire.
Boeing temporarily withdrew the Dreamliner from service earlier this year for modifications after concerns that batteries on board could cause fires.
Aviation expert Julian Bray said it was unlikely that the long-controversial lithium ion batteries in the planes were the source of either problem.
"It is very easy to jump in, as have the usual crop of former pilots turned armchair media pundits, short on hard facts, but long on hot air," he said. "They have been doing the rounds, and poking fun at the troubles the new Boeing 787 Dreamliner is going through.
"To have one Thompson Holidays highly promoted aircraft go technical dumping fuel before returning to Manchester Airport and a second Dreamliner burst into flames whilst it is empty, and the plastic aircraft just parked up in the extreme heat for a full eight hours on the hanger apron at London Heathrow, literally hot enough to fry eggs on, is a run of bad luck just gone too far."
The fire in the Ethiopian Airlines plane was in "an area well away from the previously troublesome lithium batteries, that are now grouped in three locations; and in fireproof externally vented retrofitted flush fitting pods."
Thomson Airways became the first British carrier to operate the Dreamliner earlier this week, and is taking delivery of eight of the planes.
The company had hoped to take delivery of the first of its 787s in time to start Dreamliner operations in May.
But a series of battery problems led to the grounding of the plane earlier this year while modifications were carried out.
Thomson had to scrap plans to use the ultra-green aircraft in May and June, and only received its first plane in June.
The battery problems followed endless production difficulties for the Dreamliner, which has been marketed as a quiet, fuel-efficient aircraft carrying between 201 and 290 passengers on medium-range routes.
It should have entered passenger service in 2008 but it was not until October 2011 that the first commercial flight was operated by Japanese carrier All Nippon Airways.
British Airways is taking delivery of the first two of its 24 Dreamliners, while Virgin Atlantic said it "remains committed" to taking the first of its 16 Dreamliners in September next year.
The Manchester "technical fault" was a routine problem, but an infuriating coincidence for Boeing, Bray said. "Almost every day an aircraft somewhere in the world 'goes technical' the pilot reacts to warning signals and in this case decided to dump excss fuel before returning to Manchester.
"Unfortunately that just happened to be the Thompson Holidays Dreamliner, the frst Dreamliner to be used for the holiday charter market, ruthlessly advertised as being one of key selling points for Thompson holidays."
Thomson Airways said its Dreamliner flight to Florida was flown back to Manchester airport yesterday afternoon as a "precautionary measure".
A spokeswoman said: "Thomson Airways can confirm that flight TOM126 travelling from Manchester to Sanford, Florida experienced a technical issue and the aircraft returned to Manchester Airport, as a precautionary measure.
"Passengers have disembarked and our dedicated team of engineers are now inspecting the aircraft. Our customers will be moved to an alternative aircraft to ensure they get away on their holiday as soon as possible.
"The safety of our customers and crew is of paramount importance and we would like to apologise for the delay caused."