With the introduction of the G650, Gulfstream Aerospace will be offering an airplane with an interior taller and wider than its current models

Since the Gulfstream II was introduced in 1967, the role of Gulfstream’s business jets has steadily evolved with the development of ever more efficient engines and larger fuel tankage. Gulfstreams are now making flights as long as 12 hours in duration. Trips of such extreme duration require added space for rest areas, as well as more room for perambulation and provisioning. While Gulfstream’s aircraft have always been known for their luxurious cabins, the overall cross-sections of their fuselages haves not been changed since the original Grumman Gulfstream turboprop. There was, after all, no reason to interfere with success.

Now, with the introduction of the G650, Gulfstream Aerospace will be offering an airplane with an interior taller and wider than its current models, while still preserving the performance of Gulfstream’s airplanes delivered earlier. The G650’s new BR725 engines will produce enough thrust to reach a maximum speed of Mach .925, a tiny, but significant, increment faster than Cessna’s 15-year-old Citation X, which is the civil aircraft speedster since the retirement of the Anglo-French Concorde. With this aircraft, Gulfstream is setting an entirely new standard of luxury, performance, and capability.

The G650 will boast a maximum range of 7,000 nautical miles at a speed of Mach .85, and even when cruising at Mach .90, it is expected to have a 5,000 nautical mile range. Compared to the G550, the cabin is 10.5 ft longer, 3 inches taller and 14 inches wider. That brings its length up to 53.5 ft, with plenty of space for privacy and amenities. The G650’s cabin offers a headroom of 6.5 ft, and a maximum width of 8.6 inch. Gulfstream’s innovations continue throughout the aircraft. The cabin windows, eight on each side, are the traditional large Gulfstream ovals, but are 16 per cent larger in area than the G550’, measuring 28/20.5 inches.

The maximum certificated operating altitude remains at 51,000 ft. But even in that rarefied atmosphere, the cabin’s altitude will only be 4,850 feet; at a more-typical 41,000 ft, the cabin mimics 2,765 feet, materially reducing fatigue on long trips. In keeping with Gulfstream’s standards, no recirculation of cabin air is used. The baggage compartment, accessible in flight, is 11 per cent larger than the G550s. The outside baggage door is located at 4 inches lower than on the G550, increasing its size by about eight per cent.

Structurally, the G650’s major portion is still built of aluminum. The composites are used for the horizontal stabilizer, rudder, winglets, engine cowlings, fairings, cabin floor and aft pressure bulkhead. In a departure from the round fuselage tube of the earlier Gulfstreams, the G650 uses a flattened oval that makes more efficient use of interior space without adding drag. In keeping with the Gulfstream tradition, the G650 has a huge amount of wing area, almost 1,300 sq ft, allowing it to obtain excellent airfield performance without resorting to leading-edge devices or external flap tracks. The wing also offers massive fuel tankage for the extreme-range missions envisioned for the aircraft; some 44 per cent of the G650’s takeoff weight can be uplifted as fuel, the entire 44,200 Ibs of Jet-A swallowed in 26 minutes by a redesigned refueling system.