The fourth flight-test Gulfstream G500, T4, flew for the first time on Saturday, joining three other G500s already in flight-test, the Savannah, Ga.-based aircraft manufacturer announced. T4 took off from Savannah-Hilton Head International Airport at 9:47 a.m. on Saturday, with flight-test pilots Eric Holmberg and Brian Dickerson at the controls and flight-test engineers Dominic Pompeo and Mark Mondt recording and analyzing data in the cabin.

During the three-hour, 17-minute flight, the aircraft reached its maximums of 51,000 feet and Mach 0.925. The crew also exercised all primary flight control systems, performed functional checks of air data and cabin pressurization systems and completed a series of engine performance measurements.

“The first flight of T4 speaks to the growing maturity of the G500 flight-test program and the significant development we completed before we even launched flight-test in May last year,” said Gulfstream president Mark Burns. To date, the four test aircraft have logged 580 flight hours.

One of five G500s involved in the flight-test program, T4 will be used to test avionics, flammable fluid drainage, water ingestion and select systems such as water/waste, lighting and fire protection. It will also perform flight standardization and operations evaluations. T1 is focused on envelope expansion; T2 on flight loads validation as well as aircraft performance and systems testing; and T3 on the Symmetry flight deck.

The fifth aircraft, P1, has been delivered to Gulfstream’s Savannah completions center, where it will become a fully outfitted production aircraft that will be used to test the interior elements.

T4 also represents a milestone in the G500’s development. For the first time, Gulfstream integrated product-support maintenance technicians with the flight-test team to follow the aircraft through manufacturing and flight-testing. “The collaboration between product support and flight-test throughout the G500 certification process will enhance the support available to operators when the aircraft enters service,” Burns said.

Gulfstream expects to earn FAA certification of the G500 next year. Its larger and longer-legged sibling, the G600, will follow by one year.