After multiple delays, Southwest Airlines will begin its first test flights to Hawaii on Tuesday.

The airline has been attempting to begin its long-anticipated service between California and Hawaii since late 2017, but several factors, including this year’s government shutdown, delayed the start.

To begin its certification process with the Federal Aviation Administration (FAA), Southwest’s Boeing 737 will take off without any commercial passengers. The point of Tuesday’s flight is to test the plane’s long-range navigation and communication capabilities, according to Forbes.

The flight from Oakland to Honolulu is a critical step in receiving government approval to begin flight service to the islands. Because the airline, so far, only operates flights in the continental U.S., Mexico and a smattering of airports in the Caribbean, it needs a new type of certification (extended range or ETOPS) to fly across the Pacific.

Oahu, Honolulu, Hawaii from plane
Credit: Ingus Kruklitis/Getty Images

Traveling on this flight will be FAA officials who will judge whether or not the aircraft is capable of not only completing the flight but diverting to a nearby aircraft, in the event that something goes wrong mid-flight. Flights from the mainland to Hawaii are about 2,500 miles long and take approximately five hours to complete.

"If we successfully pass this next phase, we will move into tabletop exercises with the FAA to demonstrate our full ETOPS procedures followed by ETOPS validation flights," Southwest spokesperson Brian Parrish told SF Gate. "Once we pass all phases of the ETOPS application process to the satisfaction of the FAA and receive our ETOPS authorization, we will announce further details of timing for selling and operating flights."

It is thought that several more test runs between Oakland and Hawaii will be completed within the coming days, including one flight with a simulation of an emergency diversion.

In addition to the new certification, the airline had to complete mountains of paperwork and permit applications. It seemed that the airline was close to launching the flights at the beginning of 2019. But not only were there paperwork delays, the government shutdown in December pushed back the launch period even further.

With the FAA back in commission, the airline expects to begin selling tickets to passengers in February or March. The airline expects to begin commercial service within weeks of putting flights on the market. But it will only announce further details once it has received federal clearance to begin operating flights.

The Hawaii flights are particularly high-anticipated in the aviation world because Southwest’s foray into the route is expected to bring down the costs of flights to the 50th state considerably.