Canadian ultra low-cost carrier Swoop Airlines has dropped planned flights to San Diego, California from Edmonton and Abbotsford, British Columbia long before a single flight could be operated.

The new route was announced July 2, meaning it was available for booking for less than a month before it was dropped. San Diego was to be one of only two new destinations to join the Swoop roster this winter (the other, Los Cabos, Mexico, remains on the schedule). Flights were to begin in October. At the time, Swoop called San Diego “an excellent addition to our winter line-up with a schedule that encourages weekend excursions by air.”

Affected passengers were notified by e-mail Wednesday.

Swoop is offering to re-book passengers on Westjet flights or refund the ticket price.

The airline blamed lingering effects of the grounding of the Boeing 737 Max for the cancellation. “We are notifying you that your Swoop flight to San Diego has been cancelled due to the industry-wide Boeing 737 MAX groundings and subsequent aircraft inventory shortages,” read an e-mail to passengers announcing the decision. “We understand that this impacts your travel plans and we sincerely apologize for the inconvenience.”

Even though Swoop did not fly the Max, its parent company Westjet did. It, along with airlines around the world, needs every spare aircraft it can source, leading to a shortage of older-generation Boeing 737NGs on the market, such as the ones Swoop flies.

Rival low-cost carrier Flair originally blamed a similar aircraft shortage when it cancelled all flights to the United States weeks ahead of the end of the scheduled season. Flair returned its leased 737-800NG aircraft to the lessors as a result of the decision.

The Max was grounded around the world after a pair of crashes less than five months apart. Since then, Boeing has been trying to fix a flaw in the software that governs certain aspects of the takeoff. There is no timeline for the type’s return to service.

While Boeing has set aside billions to compensate affected airlines, there has been no indication there would be compensation for knock-on effects, such as the lack of older aircraft on the re-sale market.

Swoop was expecting to receive an additional three planes by the end of the year, to bring the fleet up to 10 planes. They were to be used to reinforce the airline’s network and boost frequencies. It was not immediately clear how the decision to drop San Diego fit into the airline’s overall fleet plan.

San Diego remained as a destination in Swoop’s on-line booking system Thursday, but no flights could be found or booked. The decision leaves Swoop with 10 sun destinations on the roster, five of them in the southern United States.

Western Aviation News has reached out to Swoop for comment.

It’s not the first time the Westjet subsidiary has cancelled a route even before a single flight was flown. In the spring, Swoop cancelled planned service from Edmonton to Oakland, California as a result of poor ticket sales. Swoop President Steven Greenway told Western Aviation News the cancellation was evidence that Canadians want to travel to primary airports, such as San Francisco over Oakland, in other countries.