Gulfstream Aerospace’s fourth flight-test G600 completed its maiden flight yesterday, just six weeks after the third aircraft joined the flight-test fleet. The G600, registered as N740GD, departed Savannah-Hilton Head International Airport at 6:50 p.m. on a 1 hour 18 minute flight, during which it climbed to 51,000 feet/15,545 meters and reached Mach 0.925.

“To have four first flights and fly more than 570 hours in less than six months is a remarkable achievement,” said Dan Nale, Gulfstream’s senior vice president of programs, engineering and test. “The rapid maturity of this program is due to the work we did before the flying even started—the strategic planning, the research, the lab development—combined with the success we’ve had in the similar G500 program.”

Meanwhile, the fifth G600 test aircraft was recently delivered to the Savannah Completions center, where it will be outfitted with a production interior. It will be used to validate interior elements.

According to Gulfstream, the G600 is “on schedule” for FAA certification next year, with customer deliveries slated for later that year. Its G500 sibling is expected to receive FAA certification and enter service by the end of this year.