Canadian leisure airline Sunwing has entirely dropped its four Boeing 737 Max aircraft from the winter schedule, meaning the grounded aircraft won’t return to the fleet until May at the earliest.

“The worldwide grounding of the Boeing 737 MAX 8 aircraft created operational difficulties for us during the summer months when we did not have additional capacity within our fleet to replace this aircraft type,” said Sunwing President of Tour Operations for Sunwing, Andrew Dawson.

The airline said the type’s worldwide grounding in March has already affected more than 3,000 flights, forcing Sunwing to either lease planes, juggle schedules or cancel flights altogether.

“We acknowledge the options our customers were presented with to maintain their travel plans may have caused them an inconvenience and we appreciate the understanding and flexibility shown by both our travel agent partners and our customers during this period,” he said.

For certainty’s sake, the type has been removed from Sunwing’s schedule until at least mid-May.

The grounding of the Max in March following two fatal crashes has caused chaos for airlines around the world. Norwegian blamed the grounding for the cancellation of service between Hamilton and Dublin, its only Canadian route.

Canadian low-cost carrier blamed the Max grounding for cancelling service between San Diego and Edmonton and Abbotsford through the winter.

Air Canada and Westjet have both had to juggle schedules, with Air Canada warning the Max grounding would be felt worst in the peak summer travel season, though it would not reveal precise figures. One estimate by OAG, a data analysis firm, suggests Air Canada has lost more than 3.2 million seats of its own capacity due to the grounding, while Westjet lost just under 1.5 million seats.

Airlines have responded by switching aircraft, changing non-essential maintenance, and leasing planes where they can.

“With these changes, our customers should feel more confident about booking their vacations or destination weddings early and taking advantage of the best deals and Early Booking Bonuses we’ve ever offered,” said Dawson.

Sunwing offers service from 33 airports across the country to 45 sun destinations across the U.S.A., Caribbean, Mexico and Central America.

It says affected passengers have been advised by e-mail or through travel agents. It says the schedule on its website is what will be offered through the winter, though if the Max is approved to fly again, Sunwing would look for opportunities to add capacity on some routes or swap out aircraft. Both the 737-800 and the newer Max aircraft are configured with 189 seats, though the Max has a longer range.

No date has been set for the Max to return to service, though Boeing continues to work on fixes for a software fault suspected of contributing to the deadly crashes. The new administrator of the Federal Aviation Administration said the Max would not fly again until he was completely assured it was safe to do so.

Sunwing competes directly with Air Transat to offer flights and resorts at key sun destinations. Transat is in the midst of a takeover by Air Canada.