US flight delays: What are passengers' rights with severe disruption of Delta, United and Southwest flights?

Once again major airlines have proved susceptible to IT failures – with tens of thousands of travellers facing severe disruption.

On Monday morning Delta Airlines delayed departures on US domestic flights to many destinations because of a fault at “a company that handles the Delta Connection carriers”.

At New York’s La Guardia airport, the first wave of flights to Atlanta, Boston, Chicago, Washington DC and many other destinations suffered delays of up to three hours.

The issue hit the US at peak time at the start of the working week, and is likely to cause nationwide disruption for the rest of the day.

The airline told passengers on social media: “We are currently experiencing a system-wide outage. We are working diligently to get it back up and running.”

It later said: “A brief third-party technology issue [that] prevented some Delta Connection flights from being dispatched on time this morning has been resolved.

“Our teams are working to resolve some resulting delays.”

The Federal Aviation Authority confirmed at 08.30 ET that the issue had been resolved, but that passengers should contact their airline for more information on specific delays.

The problem is believed to rest with the system called Aerodata that prepares the “weight and balance” documentation for departure.

The disruption highlights the sharp distinctions between US and European rules on passenger care and compensation.

EU regulations specify that in the event of a protracted delay or cancellation, airlines must provide meals, and if necessary accommodation, until the passenger reaches their destination.

The duty of care applies even for events beyond the control of the airline – which may also be obliged to buy a ticket for a stranded passenger if it cannot organise an alternative in a day or two.

In contrast, US carriers offer care only when the cause is directly the responsibility of the airline.

Many of the passengers will have missed connections at major hubs. Airlines will rebook passengers free of charge on the next available flight on their services.

Travellers who are "self-connecting", for example by flying the first leg on Delta with a separate booking on Spirit, will be regarded as "no-shows" if they fail to reach the gate on time for their onward flight.

One rule that prevails in the US but not in Europe is that airlines must follow strict rules on a “Tarmac delay,” with passengers entitled to leave the aircraft after a wait of three hours aboard an aircraft on the ground.

The United Airlines flight from Manchester to New York Newark, due to leave at 9am, was eventually cancelled. The cause was unrelated to the IT problems in the US. Passengers are entitled to €600 (£515) in cash compensation – again, a European-specific route.

In 2016, Delta delayed and cancelled hundreds of flights when the power supply at its Atlanta hub was cut off for six hours.

Tens of thousands of British Airways passengers had their flights cancelled in May 2017 after the power to its IT system was interrupted by human error.