Two weeks ago, JetBlue Airways (NASDAQ:JBLU) announced two dozen new routes that will launch later this year. In addition to numerous new routes to leisure destinations -- particularly in the Caribbean and Latin America -- the expansion included a notable focus on adding "long-and-thin" transcontinental routes.

Now, JetBlue is doubling down on its transcontinental growth plans. On Tuesday, the airline announced four additional new routes, including three transcontinental routes that will take flight in late 2020.

Expanding in Hartford

JetBlue plans to add four new routes from Hartford's Bradley International Airport by year-end. On Nov. 19, it will begin flying to Cancun, one of the few international leisure destinations that's fully open for tourism.

The leisure-focused airline will start three new transcontinental routes on Dec. 18, connecting Hartford to San Francisco, Los Angeles, and Las Vegas. JetBlue executives see the potential for high leisure travel demand to all of these destinations this winter.

The timing of JetBlue's expansion announcement was driven by new rules that will allow anyone arriving in Connecticut to skip the previously mandatory 14-day quarantine if they test negative for COVID-19 within 72 hours before arrival. (The quarantine requirements had severely reduced demand for travel to and from Connecticut.)

A JetBlue Airways plane preparing to land on a runway.

Image source: JetBlue Airways.

Seizing the moment

Prior to the pandemic, JetBlue operated up to 12 daily flights from Bradley International Airport to five cities in Florida, as well as San Juan. The four new routes will make JetBlue the largest airline in Hartford in 2021 as measured by the number of destinations served, according to the company.

JetBlue will have to leapfrog several airlines to take that title, including, Southwest Airlines (NYSE:LUV). Southwest carried the most passengers of any airline in Hartford as recently as 2016, when it had 27% market share. For the past few years, it has been in the No. 2 spot for traffic, but has still served more destinations nonstop than any other airline.

Southwest was shrinking in Hartford even before COVID-19 hit. Last year, it enplaned 712,697 passengers at Bradley International Airport: down 12% from the 809,062 enplanements it logged in 2016. A seasonal flight to Las Vegas was one of the flights cut during that period. It is pulling back even more now. Over the summer, Southwest operated up to 17 daily departures to eight cities from Hartford, including several seasonal routes. However, it is cutting back to just four daily departures to two destinations for much of the fall because of weak demand.

With Southwest retrenching and legacy carriers primarily focusing on service to nearby hubs, JetBlue sees an opportunity to become significantly bigger in Hartford.

Will the new routes be profitable?

All four of the routes that JetBlue is adding from Hartford have had nonstop service at some point in the last few years. That said, the airport had lost its nonstop service to Las Vegas and San Francisco before the pandemic, and it has only had flights to Cancun and Los Angeles seasonally. Clearly, it's hard to make transcontinental service from Hartford work financially because it's a midsize market.

Thus, investors could reasonably wonder whether JetBlue will be able to turn a profit on its new routes from Bradley International Airport. In the short term, the answer is that JetBlue just wants to deploy capacity on flights that can cover their variable costs and make some contribution toward the airline's fixed costs. Management doesn't necessarily expect any of the new routes to be profitable on a fully allocated basis.

Looking further ahead, the profitability of these new routes -- like many of the other transcontinental routes announced earlier this month -- likely depends on utilizing the Airbus A220-300s that will begin joining JetBlue's fleet later this year. Because of its extremely low fuel consumption and low maintenance costs, the A220-300 will allow JetBlue to operate transcontinental routes with much lower trip costs than either it or competitors could achieve historically.

By launching a slew of new transcontinental routes in late 2020, JetBlue will generate data that will help it decide which routes offer the most promising long-term growth opportunities. Sustainable profitability may not come until JetBlue can start serving these routes with the ultra-efficient A220-300.