The second flight-test Gulfstream G600—S/N 73002 and registered as N720GD—took to the air for the first time on Friday afternoon, logging four hours, 26 minutes aloft. According to data from FlightAware, the new fly-by-wire twinjet flew 1,875 nm (mostly in a racetrack pattern off the coast from the Georgia-Florida border), reached its 51,000-foot ceiling and attained speeds up to 548 knots during its maiden flight.

“The addition of a second flight-test aircraft just 10 weeks after the first demonstrates the rigor and discipline inherent in our development programs and continues a cadence of accomplishments that will steadily move the G600 toward certification and entry into service,” said Gulfstream Aerospace president Mark Burns. “Each milestone we clear validates the significant investments we’ve made in research and development, our ground-based labs and our flight-test capabilities.”

The first G600, registered as N600G, flew on December 17 and has already logged more than 150 flight hours and has flown 22 consecutive sorties without a single maintenance discrepancy, Gulfstream said. N600G is now conducting flutter testing and expanding the flight envelope; the second G600 will soon begin flight-loads testing.

Gulfstream also recently completed ultimate load testing of the G600 structural test article, a “key step” in the certification process. Gulfstream anticipates FAA certification and first customer deliveries of the G600 next year, which is one year behind its sibling G500.