Farnborough Air Show

New Gulfstream Jets On Track For Smooth Service Entry

 - July 11, 2016, 1:00 AM
Gulfstream’s G500 retains the manufacturer’s signature nose and cockpit window profile.

Gulfstream’s new G500 business jet is making its European debut here at the Farnborough International Airshow this week. The long-range aircraft arrived on Friday after a 3,732-nautical-mile non-stop flight from the U.S. company’s Savannah, Georgia, headquarters in 6 hours, 55 minutes.

Meanwhile, Gulfstream is steadily moving toward FAA certification for the G500 next year, and much of the work done on this jet will help smooth certification of the longer G600. The G500 is set to enter service in 2018, followed by the G600 in 2019. Gulfstream has brought three other aircraft to Farnborough: a G280 midsize jet, G450 large-cabin jet and G650ER ultra-long range jet.

Four G500s are now flying in the test program, and the first G600 is nearing handover to the flight test team. Although the G600’s first flight is officially scheduled for early 2017, it could fly as early as late this year.

To date, the G500 fleet has flown more than 300 flights and 1,280 hours. Some significant milestones include maximum speed reached of Mach 0.995 (maximum operating speed is Mach 0.925), flight to 53,000 feet (2,000 feet higher than the planned certified maximum altitude) and the longest flight at seven hours, 35 minutes, with zero discrepancies.

The G500 and G600 are an entirely new family of jets, although they share many systems features and the fly-by-wire flight control technology of the G650. What sets the new models apart, however, is their cabins, larger than the G450/G550 and smaller than the G650.

The new jets’ cabins measure 7 feet 11 inches (2.41 meters) wide and 6 feet 4 in (1.93 m) tall. The G650’s cabin is 8 feet 6 in (2.59 m) wide, and the G450/G550’s 7 feet 4 in (2.24 m) wide and 6 feet 2 in (1.88 m) high.

Cabin volume of the new jets is also larger, with the G500 at 1,715 cubic feet (48.6 cubic meters) and the G600 at 1,884 cubic feet (53.3 cubic meters), compared to 1,669 cubic feet (47.3 cubic meters) in the G550. Like the G650, the new jets pressurize the cabin to a low 4,850 feet at the 51,000-foot maximum altitude to provide maximum passenger comfort and fatigue reduction.

The G600’s interior cabin length is nearly four feet longer than the G500’s, and the two jets also differ in their range capability. The G600 can fly 6,200 nm at Mach 0.85 carrying eight passengers and four crew with NBAA IFR reserves. The G500’s range under the same conditions is 5,000 nm, although with one fewer crew member. Both offer high-speed cruise of Mach 0.90.

The engines on the G600 are Pratt & Whitney Canada PW815GAs with 15,680 pounds’ thrust. The G500’s engines are PW814GAs at 15,144 pounds thrust.

The flight deck is where much has changed in the G500/G600 compared to previous models. While the G650 features fly-by-wire flight controls, its cockpit is equipped with what some might consider old-style yoke controls, which take up a lot of space and block part of the instrument panel. The new jets do away with all that clutter and incorporate sidestick controls mounted on the side ledges. Combined with the touchscreen-control displays—there are 10 total, plus one for security controls—the result is a clean-looking flight deck.

Avionics are based on Honeywell’s Primus Epic suite and are branded as Gulfstream Symmetry. Because there is no yoke, there is room for a retractable work table in front of each pilot. And the pilots’ seats no longer need a cutout at the front to accommodate yoke movement and are thus more comfortable.

The sidesticks are an implementation of BAE’s active control sidesticks (ACS). Each sidestick is electronically connected to the other, so when one moves, the other moves precisely in concert, and both pilots can see instant feedback of control movement. If both pilots try to move their ACS, it is just like trying to move mechanically interconnected yokes at the same time; only one can actuate the controls, and there is no summing of movement or prioritization as in other fly-by-wire systems. More information on the ACS is available at the BAE Systems display building here at Farnborough (near Gate E).

Recently, Gulfstream engineers completed a significant milestone, the 150-percent ultimate load test on the new jets. In this test, a ground-test airframe is subjected to stresses far greater than the airplane should ever encounter. Meanwhile a static ground test airframe is undergoing fatigue testing, which will eventually replicate three airframe lifetimes.

Gulfstream pilots already have been “flying” the new jets in laboratory simulators and fine-tuning the pilot-machine interface, but a more realistic simulator is also now in place at FlightSafety International’s Savannah, Georgia, learning center next to Gulfstream’s headquarters. The FlightSafety simulator will be certified in time for pilot training in preparation for entry into service, but in the meantime it is being used for human factors and development of flight crew procedures and other work.

Gulfstream hasn’t published any backlog numbers for the G500/G600 yet, but there are two launch customers, Qatar Executive and Flexjet.