The first flight window for the new Boeing 747-8 Intercontinental opens Sunday, and if the flight goes off, it will be the company’s third first flight in less than 18 months.

The flight depends on successful taxi tests. As a final test run of the plane’s systems, test pilots and engineers recently completed the final gauntlet test, subjecting the aircraft to a wide range of possible flight conditions and several systems failures.

The two-day gauntlet test benefits the pilots and the engineers who will monitor the aircraft’s systems during the flight-test program.

Flight-test programs for the 747-8 and 787 Dreamliner have been plagued with problems since the 787 made its first flight in December 2009 and the 747-8 freighter first took to the sky in February 2010. Both aircraft have suffered delays with customer-delivery dates being pushed until later this year.

The passenger version of the 747-8 will not require as many flights as the freighter, because much of the data gathered during freighter flight testing can be applied to the Intercontinental.

Video: Boeing