By John Dodge

CHICAGO (CBS) — Before international travelers fly across the pond on certain United Airlines flights, they will need to pass an important test–one for COVID-19. It’s the world’s first transatlantic flight to guarantee everyone over 2 years old on board tested negative for COVID-19 before departure.

Under a new trial program by the Chicago-based airline, travelers over age 2 flying on UA 17 from New York/Newark to London Heathrow Airport, will need to take a rapid COVID-19 test before they can board the flight. The four-week trial started this week.

The free COVID-19 test is administered by Premise Health at the United Club near gate C 93 at New York/Newark Liberty International airport. The test is mandatory and passengers cannot board the plane without a confirmed negative result.

“The goal of this program is ensure that all travelers on the trial flights have received a negative COVID-19 test, but it may not meet the testing requirements of your final destination,” the airline said in a statement. “Be sure to check your full travel requirements to make sure you have what you need to enter your destination country.”

United Airlines is testing some passengers for COVID-19 before boarding. (United)

United will reach out to anyone booked on one of the trial flights prior to their trip with detailed information, including how to schedule their tests. Appointments are required and must be booked in advance. Results are provided in approximately 30 to 45 minutes.

This trial will run on a total of 12 flights: Flight UA  14 from New York/Newark to London Heathrow operating on Mondays, Wednesdays, and Fridays, from Nov. 16 to Dec. 11.

When you book your flight on united.com, you’ll see an indication that a COVID-19 test is required on that flight, and you’ll be asked to confirm that you’re willing to participate. The ID Now – NAAT, rapid COVID-19 nasal swab test is produced by Deerfield, Ill.-based Abbott Laboratories.

If you receive a positive test result, you won’t be able to fly at that time and should contact your local healthcare provider, the airline said. Following CDC guidelines, United will re-book passengers after testing negative and who are no longer symptomatic.

The airline advises customers to schedule the test as early as possible and allow at least three hours between the appointment time and departure time.