The day after Delta Air Lines temporarily grounded its flights worldwide, cancellations and delays continue to pile up. Here's what's happening and what travelers can expect.
What's the latest?
Delta said it canceled 680 flights Tuesday, with an additional 2,400 flights delayed. The nation's third-largest carrier canceled about 1,000 flights Monday.
Which airport was hit hardest?
Most of the cancellations and delays were for flights in and out of Hartsfield-Jackson Atlanta International Airport, which is Delta's hub headquarters. About 73% of that airport's passengers fly Delta each year.
What is Delta doing for affected passengers?
Delta is offering $200 travel vouchers to people whose flights were canceled or delayed more than three hours. Delta is also waiving the fee normally charged to passengers for rebooking a flight, with some restrictions. Delta said it has provided hotel vouchers to several thousand customers, including more than 2,000 in Atlanta. But some consumer advocates are complaining that Delta is putting too many restrictions on its remedies, such as requiring passengers to rebook and begin the delayed trip by Friday to avoid having to pay penalties.
What caused the problem in the first place?
Delta initially said the problem began with a power outage early Monday. However, representatives for Georgia Power, which controls the power grid at the Atlanta airport, said the outage did not originate with its system but instead appears to have started in the airline's equipment. On Tuesday, company representatives said that equipment failure at Delta's Atlanta headquarters caused the power glitch. Delta said it is investigating why "some critical systems and network equipment didn't switch over to Delta's backup systems."
Has the problem been fixed?
Delta reported that its systems were fully operational by Monday at 12:40 p.m. Pacific time, but the ripple effect caused by so many canceled and delayed flights continued to disrupt the airline's flight schedule Tuesday.
If the system is back online, why do problems continue?
One reason for the lasting effect is that airlines have been packing planes to record levels in the past several years. The percentage of seats filled on commercial planes in the U.S., known as the load factor, was 83% in 2015, up from 73% in 2002. Because of the high load factor, airlines have very few empty seats in which to put passengers from canceled flights. Rebooking passengers into available seats will take time.
Airlines also have minimized planes' turnaround time — the window between when a plane lands and when it is supposed to take off again — in order to maximize revenue per plane. That means that a delay by one flight can throw off a flight schedule for days.
Is this problem common?
Aviation experts say computer problems are causing more delays and cancellations among airlines because the systems have become larger and interconnected — linking websites, airport kiosks, mobile apps and other components. Critics say airlines need to invest more in backup systems and staffing to ensure the systems can handle any crisis.
Southwest Airlines canceled more than 2,000 flights last month, blaming the problem on a faulty network router. United Airlines and Alaska Airlines blamed computer glitches last year for pricing snafus.
The Associated Press contributed to this report.
3:35 p.m.: The number of delayed and canceled flights was updated and information about hotel vouchers was added as well as consumer advocate commentary. Delta's further explanation of the outage was included.
10:50 a.m.: This article was updated throughout with Times staff reporting.
8:50 a.m.: This article was updated with additional details.