We Fly: Gulfstream G500

"

One thousand to go,” Brian Dickerson called from the right seat. I confirmed with a nod while also holding up my index finger. Hand-flying the airplane in the upper flight levels and still climbing smartly, I began adding just a tiny bit of forward pressure on the G500’s sidestick to arrest our climb at FL 470 under a brilliant blue sky over northern Florida. We’d decided to head toward Tampa for our evaluation flight after Jacksonville Center told us airline snowbird traffic along the East Coast was too intense to allow even one more jet into its airspace, especially one like ours that might have a few special airspace requests. The direction in which we headed was of little importance to me. Leveling at 47,000 feet, I realized the days of scrambling and schedule changing needed to accept Gulfstream’s invitation to fly its newest fly-by-wire business airplane had all been worthwhile. The G500, Gulfstream’s first airplane to use active fly-by-wire digital sidesticks in place of a traditional control wheel, is expected to be fully certified by early summer, perhaps even as you read this. The airplane’s non­certified status was confirmed each time Dickerson, Gulfstream’s chief demo pilot and my right-seat mentor, checked in on the radio using the “Experimental 505GD” callsign. Scott Evans, Gulfstream’s director of demonstration and corporate flight operations and our jump-seat pilot, said that because of the Experimental status, most, but not everything, I would experience in the demo aircraft would translate into the airplanes now rolling off the assembly line at the manufacturer’s Savannah, Georgia, base. At present, the seventh G500 is being completed. Gulfstream announced the all-new digital aircraft in October 2014 and flew it for the first time about six months later. Launch customers for the G500 are Qatar Airways internationally and fractional-ownership provider Flexjet in North America.

During the preflight walk-around, Evans explained some of what makes the G500 a revolutionary addition to the Gulfstream lineup. Compare the rearward angular slope on the G500 cockpit side windows to the boxier versions on the G550. There’s a sense of speed there. Aerodynamically, the wing on the G500 and the G600, the slightly longer derivative due for certification next year, is an evolutionary change from the G650’s airfoil. Steering the conversation back to speed, Evans said, “The sweep on the 500’s wing is 37 degrees versus the 30 on the G550,” translating into higher max cruise numbers.

Once level at FL 470, the true airspeed settled at 510 knots as the two Pratt & Whitney Canada PW814GA turbofan engines burned a rather miserly 2,600 total pounds of fuel per hour. This is also the first Gulfstream bizjet to fly without some version of Rolls-Royce power. At 86 feet 3 inches, the G500’s wingspan is just wide enough to offer spectacular performance, yet short enough to meet the wingspan limits of places like Aspen, Colorado. New on the G500 are flaps that span 80 percent of the wing, compared to about 60 percent on the G650. Their new blended-camber shape reduces high-speed drag while improving landing capabilities.

Much to the delight of Gulfstream customers was last fall’s announcement at the NBAA convention that the G500 had significantly bested its initial performance design numbers. Originally, Gulfstream planned for a 5,000 nm range at Mach 0.85 and 3,800 nm at Mach 0.90. Those numbers morphed into 5,200 nm at Mach 0.85 and 4,400 nm at Mach 0.90. That 16 percent range increase at high speed translates into simpler flight planning for flight crews. Another unique design requirement was that the G500 be ready to taxi within 10 minutes of the flight crew’s arrival at the aircraft, a feature pilots, as well as busy owners, will appreciate.

With all 13 seats in the spacious cabin filled, the aircraft I flew could have easily flown from Portland, Maine, to Van Nuys, California, in five hours, 25 minutes against a winter headwind and landed with a solid IFR reserve. Miami to Anchorage, Alaska, is possible, although the crew would have to pull those throttles back a bit to make it nonstop. From Aspen’s high alpine airport in the Colorado Rockies on an 85-degree day, the G500 will carry eight people just about anywhere in the continental United States nonstop.

There’s more to the G500 than speed, of course. This new airplane’s cabin is larger than a G550’s — 1,715 cubic feet versus 1,669 — but it seems even larger thanks to the 14 enormous windows Gulfstream added, the same ones, in fact, in use on the ultralong-range G650. The G500’s environmental system pumps 100 percent fresh air into the cabin at all times, and with a 10.69 psi differential, passengers will feel as if they’re still flying at 4,850 feet, even at 51,000 feet, a benefit that makes a serious difference in fatigue for all aboard. At a more timid FL 430, the cabin altitude hovers just under 3,700 feet. The 175-cubic-foot rear baggage area is of course accessible in flight. The plush seats can be quickly transformed into beds for eight, and Gulfstream has increased cabin seat pitch to 105 inches, from 97 inches in previous jets.

Up front, the G500’s new Symmetry Flight Deck addresses not only cockpit avionics but the company’s holistic approach to providing the highest level of situational awareness, comfort and growth capabilities. Experienced Gulfstream pilots may be a bit shocked the first time they enter the G500 cockpit. Gone are the old control wheels and pedestals, replaced by a pair of active digital sidesticks, opening up plenty of extra cockpit real estate. Also gone are about 70 percent of the mechanical switches, rotating knobs and push buttons from days of old — as in the G650 and earlier — all replaced by 10 touch-screen LCDs.

Gulfstream’s move to recreate the flight deck with touchscreens streamlined the entire cockpit. Seven of the touchscreens function as controllers of everything from takeoff planning to communications and environmental systems control, some focused around the throttle pedestal and three set in the overhead panel. There’s also an additional controller at the jump-seat position that can be quickly removed to replace any of the other screens should one fail. The touchscreens allow Gulfstream to update most anything in the cockpit with a simple software revision.

The mainstay of the G500’s flight deck is Honeywell’s Primus Epic system, powering four 14.1-inch LCD displays while incorporating a third-generation enhanced-vision system delivering four times better resolution than earlier versions, as well as 3D synthetic vision. The Primus Epic flight deck is powered by a triple flight management system, triple inertial reference system and three VHF navcom units accented by a pair of 24-channel WAAS GPS receivers. These make the G500 RNP 0.1-capable, as well as GPS WAAS, LPV and FANS-1A controller pilot datalink communication savvy, putting Gulfstream’s latest jet firmly at the forefront of NextGen capability.

The G500 is the first civil aircraft to operate with active sidesticks, which contrast with the passive sticks on board Dassault’s Falcon 7 and 8X, as well as the Airbus fleet. Gulfstream believes the active force-feedback sidesticks that mimic the hand gestures and feel of the pilot on the left or right significantly improve each pilot’s situational awareness. Thousands of hours of human-factors research placed the sticks in just the right location and angle for a pilot’s wrist, taking note of the human hand’s slightly forward resting angle to reduce fatigue by promoting the range of motion around the wrist and not the arm. The sidestick controllers demonstrate consistent handling qualities independent of the aircraft weight or CG location while offering full flight envelope protection without a stick pusher. The fly-by-wire system also saves weight and is easier to maintain. The G500 uses a brake-by-wire system that is electrically commanded and controlled but hydraulically actuated.

General Dynamics, Gulfstream’s parent company, made a significant investment in systems testing infrastructure to allow the engineers in Savannah to create the G500, said Dale Colter, Gulfstream’s director of lab test. “We insourced a lot of flight-control testing and were able to run these tests much more efficiently.” Gulfstream also significantly reduced the number of subcontractors to build the G500 in favor of more vertical integration in Savannah.

The G500 wing and fuselage are all metal, while the horizontal stabilizer and flight controls are composite. Gulfstream plans call for testing the G500/G600 to three lifetimes, or about 55,000 flight cycles, with a number of hard landings tossed in for good measure. By the time the G500 first departed on its maiden flight, Colter said, the airplane had been through 36,000 hours of lab testing. “If I can find the problems early in the lab, the flight-testing folks will never need to deal with them,” he said. Scott Martin, Gulfstream’s senior experimental test pilot and the G500/G600 lead pilot, along with staff scientist for human-factors engineering Susan Taylor, noted that the G500/G600 also underwent more human-factors testing than any other Gulfstream. Martin said, “Our charter was to make a 21st-century airplane as significant as when we moved up from the round-dial GIII to the EFIS GIV. We wanted to incorporate as much new technology as possible to reduce pilot workload and crew mistakes. We were told we didn’t need to keep anything from the G650.”

Taylor said Gulfstream’s move toward sidesticks was about more than mere aesthetics. “We ran a side-by-side simulator test between wheels and sidesticks with 20 pilots and measured their performance,” he said. “Within two hours of flight time, they matched or exceeded the performance of the control wheel while improving recovery from unusual attitudes.”

Martin said the huge cambered flaps on the G500/G600 evolved when “we found there was potential extra lifting capability we weren’t taking advantage of in our earlier wings. The extra curves and camber reduce high-speed cruise drag and blend in with the fixed portion of the wing. If you look at the G650, the flap only extended along 60 percent of the wing. On the G500/G600 we went to 80 percent. We also made the ailerons smaller and moved them farther out on the wing for better roll performance.” Gulfstream even eliminated all external flap mechanisms that created extra drag, he said.

Since I was one of three journalists invited to Savannah to fly the G500, I needed to be conscious of the time block I’d been given, so the APU was already running when I climbed on board to meet Dickerson sitting in the right seat. I looked around the cockpit briefly before easing myself into the left seat. The lack of knobs, switches and a control wheel, and the new touchscreens, make it clear the G500 is a clean-sheet airplane. The look of the cursor control or even the redesigned throttles gives it the feel of a finely engineered European automobile.

As I added taxi power, Dickerson reminded me about the G500’s steering. The left-side tiller is only needed for close quarters. Steering through the rudders allows the nosewheel to swing 40 degrees left or right, plenty to get us headed to SAV’s Runway 10. We were light at takeoff, 56,673 pounds to be exact, nearly 25,000 pounds under maximum gross takeoff weight, yet with enough fuel for about four hours of flying.

Touching the autothrottle button brought the power up quickly, and at our weight there was almost not enough time to notice the rocketlike acceleration before Dickerson called “rotate.” I decided before takeoff to hand-fly the G500 as much as possible to gain a feel for the airplane. Rotation with the sidestick is almost more of a thought than a conscious movement of the hand. We were quickly climbing toward FL 240 and turning southwest to Tampa to avoid that snowbird traffic.

Because of our light weight, it wouldn’t be fair to recite climb speeds and rates because they were ridiculously high. Control on the sidestick was light yet firm enough to remind me of flying an airplane like a Cirrus SR22. Climbing through FL 250 we were truing 437 knots. With a dizzying climb rate, our true airspeed increased to 502 knots through FL 350. We leveled at FL 470 in just under 20 minutes, including a few intermediate level-offs. Once level, I tested some of the touch-screen controllers and found them simple and intuitive. I just wish we’d had some bumpy air to give them a better workout.

One truly unique item was the dual-function red autopilot disconnect button. With the autopilot engaged, the button functions as a traditional automation disconnect. When hand-flying the G500, a pitch trim indicator on the PFD compares the indicated airspeed to the speed for which the aircraft is trimmed. The pilot can feel the pressure on the stick as well to compare. Once the pilot is satisfied the attitude is correct, he or she can simply touch the red trim sync button and the aircraft is instantly trimmed without any unnecessary back-and-forth trim needed.

During a few minutes of level flight at 470, I headed back to the cabin to get a sense of the noise level. I tried the boss’ seat — that first forward-facing chair on the right side — and chatted with Evans about the incredible size of the G500’s cabin. Thanks to the superb sound-attenuation work of the Gulfstream people, we were able to speak in normal voices despite a true airspeed of well over 500 knots. I had Evans talk to me while I stood near the rear lavatory too as a test. If you’re actually the boss in the front cabin seat trying to have a private conversation, you’d best whisper in the G500 or everyone in the back of the cabin will hear everything you say.

I returned to the cockpit just in time to start the right turn overhead TPA, heading back to Savannah. I hand-flew all kinds of turns in a small block of airspace, and while I never looked down at my hand, I could tell my actual wrist movements were tiny, even to elicit some seriously steep banked turns. As we started down, I slowly pulled the speedbrake control and watched the rate of descent zoom with almost no noticeable noise or vibration.

Dickerson suggested we try the RNAV Y approach to Runway 28.

I gave the automation an opportunity to impress me and activated the approach once ATC sent us direct RLENE. With clear skies and 20 miles of visibility, there wasn’t much to do except monitor, with the FMS handling the altitudes and speeds. Dickerson talked me through the flap settings for our 120-knot ref speed. For the final approach, Dickerson suggested I ease the throttles back at 100 feet and plan more for a slight check of the descent than a flare. At 100 feet, I barely eased the stick aft and waited a few seconds for the G500 to touch the runway. Reversers and a touch of brakes had us turning off at E1 for the taxi back to the Gulfstream ramp.

G500 converts should prepare for an airplane that, while fully automated, really does seem to beg a pilot to test his hand-flying skills. Gulfstream has created an 80,000-pound airplane that’s fun to fly, especially knowing all that automation is waiting in the background to step in just in case. Gulfstream quotes a delivered price of $45.5 million for a G500. General Dynamics has not yet released the backlog time and delivery data for the new aircraft, but G500 buyers are surely restless to experience the most technologically advanced business jet ever built.