Just nine years after Gulfstream Aerospace unveiled its largest and longest-range business jet—the G650—and five years after certification, 250 G650s, 120 of them the ultra-long-range G650ER, are plying the world’s skies.
To say that Gulfstream’s timing could not have been better would be an understatement. The G650 tapped into a market that was shying away from smaller jets and eager for a large-cabin ultra-long-range jet that could connect city pairs never before considered.
The G650 also represents a transition for Gulfstream, into the realm of fly-by-wire (FBW) flight controls. While such a move was inevitable—every major business jet OEM has fielded or is developing FBW jets—the G650 is unusual because it’s likely the only FBW Gulfstream that will ever feature the traditional yoke-operated flight controls. The new G500 and G600 are equipped with sidesticks, the control of choice for most FBW designs, but also noteworthy in that their sidesticks are electronically tied to each other and move together as if mechanically connected. The G650 design of two yokes mechanically connected as in traditional flight controls is a lot like Boeing’s FBW designs, thus far also employing yokes because Boeing’s philosophy is that it helps pilots maintain situational awareness when they can see the other pilot’s flight controls moving in concert with their own manipulation of the controls. The G500/G600 active sidesticks (a BAE design) also move in concert, thus maintaining the control-awareness philosophy.
There are advantages to FBW, independent of the type of cockpit control, and not just a smoother ride for passengers or better protection from exceeding certain flight parameters. For larger jets such as the G650, FBW allows designers to tune the handling of the airplane and give pilots something entirely different from what they might expect.
As a rough analog, after flying the G650ER and last year the G550, I was able to compare the handling of the two jets. The G550 has classic hydraulically operated controls, which does afford designers some latitude to improve handling, but the G550 is more work to hand fly, somewhat heavy on the controls and heavily dependent on trim to keep the workload comfortable. By comparison, I found the larger and heavier G650ER had much easier handling, something that I have also found with Embraer’s FBW Legacy 450 and 500 and Dassault’s FBW Falcon 8X