Sun Country Airlines apologized to customers for canceling six flights last weekend without notifying passengers, the latest blunder for Minnesota's hometown carrier.

The company on Wednesday said a series of unrelated problems at airports in Newark, Las Vegas and Washington, D.C., prompted the cancellations. Canceling flights or delaying departures is common in the airline industry, but Sun Country upset customers by failing to communicate about those changes before and during the disruptions on Saturday.

Eagan-based Sun Country last week completed an overhaul of the computer system that manages its operations. Unfortunately, the airline said, "a step that triggers customer communication was missed," in the case of a cancellation.

These weekend flights, which were three round trips to and from Minneapolis-St. Paul International Airport, were the first to be canceled since the overhaul and was the first real-time test for the customer communication system that should've been automatic.

Passengers were given the option to either book on the next available flight or receive a refund. Sun Country will also reimburse hotel costs incurred from the cancellation and is giving each passenger a $200 voucher toward future travel.

"We sincerely apologize to all the passengers on the six flights canceled," Sun Country said. "This is not the customer experience we strive to offer or that our guests should expect."

The cancellations were unexpected. One aircraft was suddenly out of service due to a maintenance issue, another flight was delayed due to a temporary runway shutdown at Newark, and the third cancellation was triggered when a crew "timed out" from the delays, meaning they were past the legal limit of hours worked in a day.

Notable growing pains

Sun Country has had several fits and starts as it lurches toward a new, revamped business model. The company's new leaders, who arrived in 2017, and its new private-equity owner, who bought the airline in early 2018, have been trying to modernize the fleet, the route structure and the finances with an eye toward sustainable, long-term growth.

But the process has been fast-moving and rocky, especially from a customer service standpoint — including lost or extremely delayed baggage to more egregious missteps like stranding passengers at their destination.

The airline aims to expand beyond the Twin Cities market, on which it is heavily dependent. Its growth spread its small fleet thin and, without backup airplanes on multiple flights per day, there's little room for error. Cancellations or delays can quickly ripple through its network, leading to even more frustration for passengers.

The new computer system is meant to bridge some of these communication gaps. It's not unusual for companies updating their IT systems to experience unexpected glitches that cause short-term headaches for hopefully long-term improvement.

Other ultra low-cost carriers have experienced similar growing pains, said airline expert Seth Kaplan, including Spirit Airlines. But once the major mainline carriers started offering their own basic economy fares designed to compete with them, they had to step up their reliability. Kaplan said finding that balance will be key to Sun Country's long-term success.

"Sun Country cannot provide the same level of service as Delta, they just can't afford it," Kaplan said, "but there are a lot of people in the world who are willing to give up a lot of amenities, but who still want reliability. People understand that things go wrong and there are factors, beyond the airline's control, but they want to at least be told about it."

Sun Country asked customers to be patient. "We are hopeful they will give us another chance to provide an exceptional flight experience in the future," the airline said.

Kristen Leigh Painter • 612-673-4767