Fury as tens of thousands of passengers are left stranded at airports around the world after ALL Delta Air Line flights are grounded for five hours by computer crash

DELTA Air Lines systems crashed worldwide, leaving tens of thousands of travellers stranded with none of the airline's planes able to take off.

Around 300 flights were cancelled due to a power outage that saw one of the world's largest airline systems crash, leaving frustrated travellers waiting for more than four hours.

Flight crew were forced to issue hand-written boarding passes and manually enter passport details with hordes of angry travellers forced to queue for hours without knowing the fate of their flight.

The ground stop has since been lifted more than four hours after the systems crash, and by mid-afternoon UK time, about 10.30am ET, 800 of the nearly 6000 scheduled flights had operated.

Travellers took to social media to vent their frustration with some even giving up and going home.

After hours of confusion and delays, the airline announced on social media that the ground stop had been lifted with "limited departures resuming" following the power outage in Atlanta that impacted Delta computer systems.

Amanda Jackson told The Sun Online that she had been left at Heathrow for more than three hours trying to drop her bags.

She said: "I am through security now with a scrappy handwritten boarding pass, but absolutely no news about what's going on."

Travelling to Seattle then onto Alaska for a family celebration, she said she was still hopeful she would make it.

She said: "It took us 3 hrs to drop bags, staff are pretty clueless and people are just getting on being very good."

Travellers were forced to sleep on the floor with little news of when their flight would take off.

Others have been given food vouchers while others were given free food and drinks as the wait continues.

Sandra Longdon said her husband Tony was heading to the US for a couple of days for work but was left stranded at Heathrow in the Delta delays.

She said: "He's just messaged me to say that he's at the gate but there's no sign of boarding. It sounds like the computer system is partially fixed but they can't produce flight plans so won't be going anywhere."

She said her husband had arrived at Heathrow for his 9.40am flight to Minneapolis find the airport in chaos.

Ms Longdon said: "It was a right mess when he got there."

But she said the airport and airline had been trying their best to rectify the global issue with her husband now able to board his flight.

Peter Taylor was ready for a morning flight from Heathrow to Boston this morning when he was hit with a delay of more than six hours.

Intending on travelling to the US for barely two days for business, Mr Taylor was forced to watch the precious amount of time he had in Boston dwindle away in the Delta delays.

He told The Sun Online: "I was heading to Boston and I was only going for two days so in the end I just gave up.

"The jetlag wasn't going to be worth it."

The project management speaker and author said passengers only realised something had gone wrong when the staff began to key in their passport details manually.

He said: "We told us about the global systems outage and from that point onwards it would be about an hour until we left. But it didn't end up like that."

Mr Taylor ended up giving up and getting a refund on his flight, saying the trip was no longer worth it.

The airline said: "A Delta ground stop has been lifted and limited departures are resuming following a power outage in Atlanta that impacted Delta computer systems and operations worldwide. Cancellations and delays continue.

"Customers heading to the airport should expect delays and cancellations. While inquiries are high and wait times are long, our customer service agents are doing everything they can to assist. There may also be some lag time in the display of accurate flight status at delta.com, the Fly Delta App and from Delta representatives on the phone and in airport."

The airline recently warned customers should expect further delays and cancellations.

Delta Air Lines has since said all travellers on Delta flights on August 8 would be able to claim a refund.

In a statement, the airline said: "If your flight is canceled or significantly delayed, you are entitled to a refund. Even if your flight is not canceled, you may make a one-time change to your ticket without fee if you are scheduled to travel to, from, or through the following destination(s) on Delta."

Delta Air Lines runs more 5000 flights a day.

People waiting at Heathrow airport this morning, hoping to travel to places including Athens, Las Vegas and Tokyo, were left stranded at Terminal 4.

The outage has also impacted the Keflavik International airport in Iceland, Rome Ciampino Airport, Lihue airport in Hawaii and the Seattle-Tacoma International airport, according to social media reports.

Passengers were given little news or updates around when their flight will be ready to with upset travellers taking to social media to complain.

Delta News released a statement, saying: "A power outage in Atlanta, which began at approximately 2:30 a.m. ET, has impacted Delta computer systems and operations worldwide, resulting in flight delays. Large-scale cancellations are expected today.

"All flights enroute are operating normally. We are aware that flight status systems, including airport screens, are incorrectly showing flights on time. We apologize to customers who are affected by this issue, and our teams are working to resolve the problem as quickly as possible. "