Gulfstream Exec Touts G650 Engineering Written 26 June 2015
by Lawrence Garrett, AIAA web editor
There are “well over 100 airplanes [now] in service,” Erbacher said in his keynote address. “Customers love the airplane” in part because it is “continually breaking speed records.”
Erbacher described a long list of notables. The plane was developed quickly considering its many innovations. Gulfstream began designing the 650 in May 2005 when the company received approval from its parent company, General Dynamics. The aircraft was certified on September 7, 2012, entering service near the end of 2012.
With two Rolls-Royce BR725 engines, the aircraft has a top speed of Mach .925 — nearly the speed of sound.
The G650’s structure and engines are designed so that the cabin can be pressurized to a high level. The result is that passengers feel like they’re breathing at an altitude of 3,000 to 4,000 feet. As Erbacher described it, when the 650 is cruising at 41,000 feet, its cabin altitude is less than 3,000 feet, and “at 51,000 feet, it has a cabin altitude of 4,850 feet, which is the lowest in the industry,” he said.
But one of the most significant aspects of the project, he said, is that these accomplishments spring from a company that had never built an entirely new airplane. The famous 1960s-era Gulfstream 2, or G2, was built by Grumman Aerospace.
“Every other airplane since the G2 has been a derivative of the G2, including the G5, the 550, the 450, they’re all derivatives of the G2. So, when we started the 650, this was the first new jet that Gulfstream itself had ever designed,” he explained.
Gulfstream introduced a three-axis fly-by-wire system with a fully electronic backup, making the G650 the “first business aircraft to certify a fully electronic backup system,” according to Erbacher.
The plane went through “over 1,400 hours” of wind tunnel testing to validate design, performance, and handling characteristics. On top of that, “thousands of hours” of computational-fluid-dynamics modeling were done. “What’s amazing is that what we learned is [that] the engineers did a great job. The CFD predictions matched what was in the tunnel – there was nothing there that was different, which is a tribute to the engineering.”
Erbacher also described some of the advanced manufacturing techniques used on the G650, including bonded panels with stringers, a “first” at Gulfstream, as well as reliance on determinate assembly, a process for precisely placing parts. This “reduced the part count by about 50 percent,” he said. At the assembly plant in Savannah, Georgia, the aircraft “goes together very easily; it’s like watching Legos go together,” he said.
Before concluding his remarks, Erbacher took a moment to offer thanks on behalf of his team for having been named this year’s winner of the Robert J. Collier Trophy. “The G650 is an amazing airplane. It’s changed the life of Gulfstream. It’s changed the lives of a lot of people. It’s been fantastic, and we were very, very honored to receive this accolade.”
Erbacher promised that “the speed records will continue.”
A G650 reportedly costs about $65 million. Erbacher said there is nevertheless a huge backlog of orders, and he quipped: “Thank God.”