Fourth Gulfstream G500 Joins Test Fleet American airframer Gulfstream just announced further expansion of the testing regime for the G500 aircraft. They have added a fourth aircraft to the testbed team and T4 has already made its first flight. The initial flight lasted approximately 3 hours and 17 minutes. The G500 took off from the Savannah-Hilton Head International Airport at 9:47 a.m. on Saturday, Feb. 20, with Flight Test pilots Eric Holmberg and Brian Dickerson at the controls. Flight Test engineers Dominic Pompeo and Mark Mondt provided on-board test and data analysis.