Thousands of passengers remained stranded on Wednesday as Spirit Airlines entered its fourth day of flight delays and cancellations.
According to flight tracker FlightAware, 367 of the budget airline's flights – or 53% of its schedule – were canceled as of 12:30 p.m. ET as distraught customers continued to look for answers both in-person and on social media.
More than 40 flights were shown as delayed.
On Tuesday, Spirit canceled around 60% of its schedule, or more 400 flights, and nearly 100 other flights were late.
Photos showed massive lines both inside and outside multiple airports, with frustrated passengers sitting on top of their bags as they continued to wait.
While passengers at airports have previously speculated that the travel disruptions were due to pilot strikes, both the Air Line Pilots Association and Spirit told Fox Business those reports are inaccurate.
Spirit Airlines said it had proactively canceled some flights in order to "reset" the operation.
"We’re working around the clock to mitigate the travel disruptions caused by overlapping operational challenges including weather, system outages and staffing shortages in some areas of the operation," spokesman Erik Hofmeyer said. "We’re working to provide refunds for cancellations and, when possible, to re-accommodate our guests" on other flights.
A Tuesday morning outage also affected crew scheduling, preventing airline officials from rescheduling crews, according to a person familiar with the situation.
"We understand how frustrating it is for our Guests when plans change unexpectedly, and we're working to find solutions," the South Florida-based airline told FOX Business on Tuesday. "We ask Guests to actively monitor their emails and flight status before heading to the airport."
On Spirit's Twitter account, the airline instructed passengers who needed assistance to visit their webchat.
Customers have complained about being put on hold for hours when placing phone calls to Spirit.
With air travel reaching new pandemic-era highs, airlines like Spirit are scrambling to meet the increased demand.
U.S. air travel has recovered to approximately 80% of 2019 levels, with more than 2.2 million people going through airport checkpoints last weekend.
After receiving $54 billion in taxpayer dollars to keep employees on the payroll throughout the COVID-19 pandemic, airlines still reduced staff.
The industry's recovery may face another public health threat as the coronavirus delta variant continues to spread, but officials said they have not seen bookings suffer due to the strain.
FOX Business' Daniella Genovese, Lucas Manfredi and The Associated Press contributed to this report.