Flybe has gone into administration with all flights to and from the UK cancelled, the airline has stated.
Brits hoping to fly with the regional carrier have been urged not to head to airport by authorities and that flights will not be rescheduled.
The UK Civil Aviation Authority (CAA) also made the announcement about Flybe with consumer director Paul Smith saying that it will be "distressing for all its employees and customers".
Three early Flybe flights from Belfast, two from Birmingham and two from Amsterdam were all showing as 'scheduled on time' on Flybe's online flight status live tracker at 5am.
But the CAA urged ticket-holders to instead check its website for the latest information.
Mr Smith said: "It is always sad to see an airline enter administration and we know that Flybe's decision to stop trading will be distressing for all of its employees and customers.
"We urge passengers planning to fly with this airline not to go to the airport as all Flybe flights are cancelled. For the latest advice, Flybe customers should visit the Civil Aviation Authority's website or our Twitter feed for more information."
It comes after Flybe returned to the skies in April following an earlier collapse.
It operated up to 530 flights per week across 23 routes, serving airports such as Belfast City, Birmingham, East Midlands, Glasgow, Heathrow and Leeds Bradford.
A Government spokesperson said: "This remains a challenging environment for airlines, both old and new, as they recover from the pandemic, and we understand the impact this will have on Flybe's passengers and staff.
"Our immediate priority is to support people travelling home and employees who have lost their jobs.
"The Civil Aviation Authority is providing advice to passengers to help them make their journeys as smoothly and affordably as possible. The majority of destinations served by Flybe are within the UK with alternative transport arrangements available.
"We recognise that this is an uncertain time for affected employees and their families. Jobcentre Plus, through its Rapid Response Service, stands ready to support any employee affected."
Flybe was pushed into administration in March 2020 with the loss of 2,400 jobs as the Covid-19 pandemic destroyed large parts of the travel market.
Before it went bust it flew the most UK domestic routes between airports outside London.
Its business and assets were purchased in April 2021 by Thyme Opco, which is linked to US hedge fund Cyrus Capital.
Thyme Opco was renamed Flybe Limited and it had been based at Birmingham Airport.
