The managing director of Manchester Airport issued a personal apology to passengers on Sunday evening after all flights from Terminals 1 and 2 were cancelled.
The airport said a “major power cut” had caused “widespread disruption” which was particularly disruptive to departures.
Chris Woodroofe, the airport’s managing director, said that although cancellations and delays would continue on Sunday, he hoped normal operations would resume on Monday.
In a video recorded outside the airport, he said: “My sincere apologies to all passengers affected by what happened at Manchester Airport today.”
He said an “early morning failure” had caused a “major power spike” in the airport’s electrical system.
“It damaged some very important equipment for our departure security and departure baggage systems.
“That means that both Terminal 1 and Terminal 2 were unable to leave aircraft today and as a result we were unable to have aircraft coming in because there is no space to park those aircraft on the airfield.”
He added: “We are working closely with our airlines to try to recover the operation and understand what passengers can be booked on future flights.”
Mr Woodroofe described it as “very difficult circumstances”.
He continued: “The good news is we’re really hoping to get this through the afternoon and evening so we’re back to normal operations tomorrow.”
An airport spokesman said earlier: “Manchester Airport was affected by a significant power cut early this morning. Power was restored but the outage affected key systems, including boarding card processing and baggage screening, causing significant delays, particularly in Terminals 1 and 2.
“All flights from Terminals 1 and 2 are being canceled until further notice and passengers due to travel from these terminals are advised not to come to the airport and stay in touch with their airlines.”
The power cut is understood to have affected nearby businesses, including hotels, as well as the airport, which was trying to get all the passengers stuck in the terminals on their flights to clear the queues.
The airport said it had backup generators that restored power relatively quickly after the power cut.
However, the outage affected the security systems that communicate with the UK Border Force, as well as the baggage systems, both of which are not designed to be switched off and take time to get back up and running .
Katie Phillips posted a video on social media showing the chaos at the baggage carousel in Terminal 1.
She said: “Power cut at Manchester Airport T2 & T3 landed at all to T1 baggage thrown on a roundabout.
Ms Phillips, who was traveling with her four-month-old and toddler, said she landed at 1am and didn’t get her bags until 4am.
One Singapore Airlines flight that arrived from Houston in Texas had to go to London Heathrow and another flight, which came in from Singapore, was forced to land at London Gatwick.
An Etihad Airways flight from Abu Dhabi to Birmingham Airport has been diverted.
EasyJet, which operates flights from Terminal 1, said there were “very long queues” at security and disruptions to baggage processing, meaning passengers could only board flights with cabin luggage.
He said: “Although it is beyond our control, we would like to apologize for any inconvenience caused.
“We are doing our best and working closely with airport staff to minimize disruption.”
A Virgin Atlantic spokesman said: “Following a site-wide power outage at Manchester Airport, baggage systems are currently not operational.
“Our teams are working closely with the airport authorities and keeping our customers informed of the latest information.
“Atlantic flights are currently departing but may be slightly delayed.”
The country’s third busiest airport said some flights had already been canceled and more were expected to be affected throughout the day.
“Passengers due to fly from Terminal 3 should arrive at the airport as normal unless advised otherwise by their airline, but may be affected by delays,” the airport spokesman said.
Priority would be given to flights of those already at the airport as efforts to “work through that backlog” continued, a spokesman said.
The power outage means there may be situations where some people’s luggage will not be on flights.
An airport spokesman said: “We are working to get passengers who are already at the airport on their flights. In some cases there may not be baggage on those flights due to the disruption caused by the outage.
“We will work with airlines to ensure that passengers are reunited with any baggage not on their flight as soon as possible.
“We apologize for any inconvenience and aim to restore normal service as soon as possible.”
The electricity supply went out around 1.30am but has since been restored, although it will take time to get systems up and running again.
Bobbi Hadgraft, who is traveling to watch England at Euro 2024, told BBC Radio Manchester that she arrived at the airport at around 4am to see “massive queues” outside Terminal 1.
“We were worried we would miss our flight,” she said, adding that the power outage affected display boards and scanners and crew members had to guide passengers around the site.
Meanwhile, railway passengers experienced travel chaos on Sunday due to a signaling problem on busy routes.
South Western Railway urged people not to attempt to travel between Brockenhurst and Eastleigh or between Fareham and Southampton as lines were blocked.
A message to passengers said: “We are currently unable to operate a service between Brockenhurst and Eastleigh in both directions.
“We are currently unable to operate a service between Fareham and Southampton Central.
“Train services passing through these stations may be cancelled, delayed or revised. Submissions are expected until the end of the day.”