Gulfstream G500/G600

G500

G500 at EBACE 2018

The G500 was taxiing under its own power at its unveiling on October 14, 2014.^[10] It first flew on May 18, 2015.^[1] It was initially planned to be certified in 2017.^[5][12] In May 2017, the test fleet of four G500 prototypes and the first production aircraft, made over 745 flights in two years for 2,900 flight hours, on track for the certification by the end of the year.^[13]

In August 2017, the FAA issued the G500 a type inspection authorisation to allow in flight evaluation. The five G500 test aircraft have logged more than 3,100h over 820 sorties and completed cabin systems, brakes, lighting, fly-over noise and fuel systems tests. The fifth G500, with a complete interior, will be the first to enter service, as a demonstrator, before customer deliveries in early 2018.^[11] Through August 20, the G500s have flown 3,460 h over 905 flights, reaching Mach 0.995 and FL530.^[14]

For the October 2017 NBAA show, the five G500s were completing their campaign with 995 flights and 3,690h - 10h 19min for the longest - the first delivery schedule was maintained as certification was pushed until early 2018.^[3] Mach 0.85 range for the G500 was extended by 200 nmi to 5,200 nm/9,630 km and by 600 nm/1,111 km to 4,400 nm/8,149 km at Mach 0.90.^[15]

The 300 flights hours of function and reliability testing required for FAA type certification was to be completed in summer 2018 after 240 were done at the end of May 2018 covering 100,300 nmi in 69 flights, along known icing flight and high-elevation certification tests: the five flight-test G500s made 1,355 flights in 4,955 hours.^[16]

On July 20, 2018, Gulfstream announced it received both its type certification and production certificate from the FAA, before first delivery in the fourth quarter.^[17] As nacelle supplier Nordam filed for bankruptcy on 23 July, initial deliveries will be slowed.^[18]

The first G500 was delivered on September 27, 2018.^[19] On October 1, Gulfstream announced the acquisition of the nacelle manufacturing line from Nordam.^[20]

G600

The longer G600 had its first flight at Savannah-Hilton Head International Airport on December 17, 2016.^[2][21] Four flight-test aircraft and a production G600 will be used for the test program for a scheduled 2018 introduction:^[22]

• T1, which flew 311 hours in five months, will test brakes development, flying qualities, stall speeds, air data and RVSM;
• T2, which has 52 flight hours in two months, will focus on loads, climb performance, flyover noise and function and reliability testing;
• T3 first flew on May 5, 2017 and will be used for field performance, ice protection, cabin pressurization and oxygen system testing;
• T4 will test automatic flight control systems, avionics and the fuel system;
• P1, the first production G600, will test cabin systems and the production interior.

In August 2017, the fifth was being outfitted for its third quarter first flight.^[11] Through August 20, the four G600s have logged 780 h in 175 flights, the longest lasting 13 h 5 min, it completed testing for initial flight envelope expansion and flying qualities, flutter, brakes, low speed or stall, loads calibration, parameter identification and climb performance, the fifth test aircraft will fly later in the quarter.^[14]

For the October 2017 NBAA show, five G600 were flying as it was to be introduced in early 2019.^[3] Range for the G600 was extended by 300 nmi/556 km for both Mach 0.85 to 6,500 nm/12,038 km and Mach 0.90 to 5,100 nm/9,445 km.^[15]

Certification and introduction for the G600 should happen in 2018 like for the G500.^[4] The five flight-test G600s accumulated 1,950 hours in 510 flights, were completing mechanical systems certification testing in May 2018 before airfield-performance testing in summer.^[16] By August, 600 flights over 2,290 hours were completed after trials for ice shapes and stall speed testing and before field-performance testing, towards U.S. approval by year-end and deliveries in 2019.^[23]

Airframe

G500 cabin

Both models have a four circular arcs cross-section fuselage, similar to the Gulfstream G650, with a 7 in (18 cm) reduction in width and height. Similar in dimension to the Dassault Falcon, the G500/600 have 2 in (5.1 cm) more headroom, 7 in (18 cm) more cabin width and 8 in (20 cm) more floor width than Gulfstream's G450 and G550.^[24] The fuselage has an external height of 8 ft 4 in (2.54 m), and width of 8 ft 5 in (2.57 m). The production G500 will have 14 windows, two more than the prototype models.^[12]

The wing is a supercritical design with a 0.87 to 0.88 drag divergence Mach number depending upon lift coefficient.^[8] It is based on the G650's wing design with the same 36° sweep. The G600's wingspan will be 8 ft (2.4 m) wider than the G500, allowing for 10,000 lb (4,500 kg) of additional fuel. Both models have a new tail design based on the aerodynamic shape and systems of the G650's tail.^[7]

The airframe is primarily composed of high-strength aluminum alloys with limited use of steel and titanium alloys. The horizontal stabilizer, fairings, main landing gear doors, rudder and elevators, radome, rear pressure bulkhead and winglets are composite materials. The semi-monocoque fuselage structure is made of stressed skin, frame and longeron.^[8]

Engines

PW815 on a G600

The G500/G600 will be powered by the Pratt & Whitney Canada PW800 series turbofan engines (PW814 for G500 and PW815 for G600) which was originally conceived for the Cessna Citation Columbus program. The PW800 is based on the Pratt & Whitney Geared Turbofan core without the gear reduction. The departure from Rolls-Royce Aero Engines is a first for Gulfstream.^[9] For the G500 in cruise, at FL400, ISA -5°C, total fuel flow is 2,920 lb (1,320 kg)/h at M0.90/510 kn (945 km/h) TAS, 2,400 lb (1,090 kg)/h at M0.85/476 kn (882 km/h) TAS.^[25] At FL450, Mach 0.90/506 kn (937 km/h) TAS and ISA -8°C, it burns 2,600 lb (1,200 kg)/h.^[26]

Systems

G600 flight deck

Electric and hydraulic systems are from the G650, as the digital air data computers, secondary power distribution with electronics, cabin acoustical treatment, primary avionics, satcom, improved cabin management system and digital fly-by-wire system. The oxygen, cabin pressurization, landing gear control, aircraft health and trend monitoring systems are adapted from the G650.^[24] The auxiliary power unit is a Honeywell HTG400G.^[8]

It is equipped with BAE Systems active sidesticks, appearing to be mechanically linked by being electrically back-driven, the first civil aircraft to be so.^[8] The Honeywell Symmetry Flight Deck features four portrait main displays, three touchscreens on the overhead panel instead of stand-alone switches ; there are four touchscreens in the glareshield and left and right touch standby displays at each seat. The enhanced flight vision system is displayed through 42×30° field-of-view head-up display, along a complete avionics suite.^[27]