Swedish Air Force designations: S 102B Korpen and Tp 102
US military designations: C-20F/G/H
JASDF designation: U-4
Engineering designation: G-1159C

TYPE: Long-range business jet.

PROGRAMME: Design of Gulfstream IV started March 1983; manufacture of four production prototypes (one for static testing) began 1985; first aircraft (N404GA) rolled out 11 September 1985; first flight 19 September 1985; first flight of second prototype 11 June 1986 and third prototype August 1986; FAA certification 22 April 1987 after 1,412 hours' flight testing; certificate is extension of original Gulfsteam II, first approved on 19 October 1967. Westbound round-the-world flight from Le Bourget Airport, Paris, on 12 June 1987, covering 19,887.9 n miles (36,832.44 km; 22,886.6 miles), took 45 hours 25 minutes at average speed of 437.86 kt (811.44 km/h; 504.2 mph) and set 22 world records; eastbound round-the-world flight in N400GA from Houston, Texas, on 26 and 27 February 1988 covered 20,028.68 n miles (37,093.1 km; 23,048.6 miles) in 36 hours 8 minutes 34 seconds at average speed of 554.15 kt (1,026.29 km/h; 637.71 mph), setting 11 records. In March 1993, Gulfstream IV-SP N485GA set new world speed and distance records in class, at 503.57 kt (933.21 km/h; 579.87 mph) and 5,139 n miles (9,524 km; 5,918 miles) respectively, on routine business flight from Tokyo, Japan, to Albuquerque, USA. Russian Federation and Associated States (CIS) certification achieved in June 1996. FAA approval for RVSM operation of Gulfstream IV series granted 11 August 1997. European JAA validation of FAA certification of Gulfstream IV and IV-SP achieved 16 October 2001. Gulfstream IV-SP holds 75 flight records; by September 2003 fleet had accumulated more than two million flying hours, with a 99.7 per cent despatch reliability rate.
G3O0/G400 introduced from January 2003 on common production line; G400 completed to full specification; G300 as baseline aircraft, with only those avionics and fittings specified by customer and lavatory location only at rear. G400 assembly includes 360 items installed on production line which previously were part of outfitting. JAA validation of FAA certification achieved for G300 and G400 in July 2003.

CURRENT VERSIONS: Gulfstream IV: Built until 1992. MTOW 33,203 kg (73,200 lb).
Gulfstream IV-SP: Improved (Special Performance), higher-weight version announced at NBAA Convention, Houston, in October 1991. Prototype (N476GA, converted from standard) first flown 24 June 1992; designation applied to all new IVs sold after 6 September 1992 (c/n 1214 and upwards); maximum payload increased by 1,134 kg (2,500 lb) and maximum landing weight increased by 3,402 kg (7,500 lb), with no increase in guaranteed manufacturer's empty weight. Payload/range envelope extended; expanded capability Honeywell SPZ-8400 flight guidance and control system. Production ended 3 December 2002 when 500th and final IV/IV-SP (N499GA: c/n 1499) rolled out.
Detailed description applies to Gulfstream IV-SP, except where otherwise indicated.
Gulfstream IV-MPA: Multipurpose Aircraft, announced September 1994; derived from US Navy C-20G Operational Support Aircraft (which see, below) to provide commercial operators with quick-change interior for up to 26 passengers in high-density shuttle layout, low-density executive configuration, 2,177 kg (4,800 lb) cargo capacity, or combination; large cargo door and larger/ additional emergency exits standard.
Gulfstream G300: Mid-range (basic specification) version, announced on the eve of the NBAA Convention at Orlando, Florida, 8 September 2002; First aircraft A6-RJA (c/n 1503) delivered 6 August 2003 to Royal Jet of Abu Dhabi, which has ordered two, in miltipurpose aircraft (MPA) configuration.
Gulfstream G400: New (full specification) version, announced on the eve of the NBAA Convention at Orlando, Florida, 8 September 2002. Generally as IV-SP except HUD standard. First aircraft N520GA (c/n 1500) exhibited at EBACE, Geneva, 7 to 9 May 2003 (as N400GA).
Gulfstream G450: Described separately.

CUSTOMERS: Total 500 Gulfstream IV and IV-SPs built by December 2002 (c/n 1000 to 1499), when production switched to G300/G400. Deliveries totalled 22 in 1997, 32 in 1998, 39 in 1999, 37 in 2000, 36 in 2001 and 17 in the first six months of 2002 (no further announcements).

COSTS: US$31 million 'green' G400 (2003).

DESIGN FEATURES: Rear-engined, T-tail configuration, with all flying surfaces sweptback; wing mounted below cabin. Differences from Gulfstream III include aerodynamically redesigned wing, with winglets, contributing to lower cruise drag; wing also structurally redesigned with 30 per cent fewer parts, 395 kg (870 lb) lighter and carrying 544 kg (1,200 lb) more fuel; increased tailplane span; fuselage 1.37 m (4 ft 6 in) longer, with sixth window each side; Rolls-Royce Tay turbofans; flight deck with electronic displays; digital avionics; and fully integrated flight management and autothrottle systems.
Advanced sonic rooftop aerofoil; sweepback at quarter-chord 27° 40'; thickness/chord ratio 10 per cent at wing station 50, 8.6 per cent at station 414; dihedral 3°; incidence 3° 30' at root, -2° at tip; NASA (Whitcomb) winglets.

FLYING CONTROLS: Conventional. Hydraulically powered flying controls with manual reversion; trim tab in port aileron and both elevators; two spoilers on each wing act differentially to assist aileron and, with third spoiler each side, act collectively as airbrakes and lift dumpers; single-slotted Fowler flaps; four vortillons and a single 'tripper' strip under leading-edge of each wing ensure inboard part of wing stalls before outboard section; variable incidence tailplane.

STRUCTURE: Light alloy airframe except for carbon composites ailerons, spoilers, rudder and elevators, some tailplane parts, some cabin floor structure, and parts of flight deck; winglets of aluminium honeycomb. Wing box manufactured by Aerostructures Corporation.

LANDING GEAR: Retractable tricycle type with twin wheels on each unit. Main units retract inward, steerable nose unit forward. Mainwheel tyres size 34x9.25-16 (18 ply) tubeless; pressure 12.07 bar (175 lb/sq in). Nosewheel tyres size 21x7.25-10 (10 ply) tubeless, pressure 7.93 bar (115 lb/sq in); maximum steering angle ±82°. Dunlop air-cooled carbon brakes; Aircraft Braking Systems anti-skid units and digital electronic brake-by-wire system. Dowty electronic steer-by-wire system. Turning circle about wingtip 14.43 m (47 ft 4 in); about nosewheel 12.04 m (39 ft 6 in).

POWER PLANT: TWO Rolls-Royce Tay Mk 611-8 turbofans, each flat rated at 61.6 kN (13,850 lb st) to ISA +15°C. Target-type thrust reversers. Fuel in two integral wing tanks, with total capacity of 16,542 litres (4,370 US gallons; 3,639 Imp gallons) in GIV/G400 and 15.141 litres (4,000 US gallons; 3,331 Imp gallons) in G300. Single pressure fuelling point in leading-edge of starboard wing. In 1999 Gulfstream considered re-engining of IV-SP as part of product improvement policy, possibilities including Rolls-Royce Deutschland BR710, and General Electric CF34; in May 2000 it placed an order for US$1.4 billion with Rolls-Royce for improved Tays.

ACCOMMODATION: Crew of two plus cabin attendant. Standard seating for up to 19 passengers (typically 12 to 14 in corporate configuration) in pressurised and air conditioned cabin. 'Quick Change' cargo/passenger version, certified for up to 26 passengers, announced 22 December 1993. Galley, lavatory and large baggage compartment, capacity 907 kg (2,000 lb), at rear of cabin. Integral airstair door at front of cabin on port side. Baggage compartment door on port side. Electrically heated wraparound windscreen. Six cabin windows, including two overwing emergency exits, on each side.

SYSTEMS: Cabin pressurisation system maximum differential 0.65 bar (9.45 lb/sq in) maintains 1,980 m (6,500 ft) cabin altitude at 13,715 m (45,000 ft); dual air conditioning systems. Two independent hydraulic systems, each 207 bar (3,000 lb/sq in). Maximum flow rate 83.3 litres (22 US gallons; 18.3 Imp gallons)/min. Two bootstrap-type hydraulic reservoirs, pressurised to 4.14 bar (60 lb/sq in). Honeywell GTCP36-100G APU in tail compartment, flight rated to 12,500 m (41,000 ft) since s/n 1156. Electrical system includes two 36 kVA alternators with two solid-state 30 kVA converters to provide 23 kVA 115/ 200 V 400 Hz AC power and 250 A of regulated 28 V DC power; two 24 V 40 Ah Ni/Cd storage batteries and external power socket. Wing leading-edges and engine inlets anti-iced.

AVIONICS: Comms: Dual VHF/HF transceivers, transponders and cockpit audio systems; cockpit voice recorder; Calquest CD-400 satellite communications equipment optional.
Radar: Digital colour weather radar.
Nav: Dual VOR/LOC/GS with marker beacon receivers; dual DME; dual ADF; dual radio altimeters; optional MLS, GPS and VLF Omega. Optional Northstar Technologies CT-1000 flight deck organiser.
Flight: Honeywell SPZ-8400 digital AFCS; Honeywell SPZ-8000 flight management system (FMS); dual fail-operational flight guidance systems including autothrottles; dual air data systems; dual flight guidance and performance computers; dual laser IRS; AHRS; VNAV; flight data recorder. System integration is accomplished through a Honeywell avionics standard communications bus (ASCB). Optional TCAS and Honeywell EGPWS.
Instrumentation: Six 203 x 203 mm (8 x 8 in) colour CRT EFIS screens, two each for primary flight display (PFD), navigation display (ND) and engine instrument and crew alerting system (EICAS). Honeywell/BAE HUD 2020 head-up display received FAA approval for Cat. II operations in early 1997, with first installation in Gulfstream IV-SP completed in May 1997. Northstar Technologies CT-1000G flight deck organiser system optional. EVS system used on Gulfstream V received FAA certification for installation on IV-SP on 19 December 2002.
Self-defence: Optional BAE Systems AN/ALQ-204 Matador IRCM available at cost of US$3.5 million.

Data applicable to both versions, except where stated.

Wing span over winglets 23.72 m (77 ft 10 in)
Wing chord: at root (fuselage c/l) 5.94 m (19 ft 53/4 in)
at tip 1.85 m (6 ft 03/4 in)
Wing aspect ratio 6.4
Length overall 26.92 m (88 ft 4 in)
Fuselage: Length 24.03 m (78 ft 10 in)
Max diameter 2.39 m (7 ft 10 in)
Height overall 7.44 m (24 ft 5 in)
Tailplane span 9.75 m (32 ft 0 in)
Wheel track 4.17 m (13 ft 8 in)
Wheelbase 11.61 m (38 ft 11/4 in)
Passenger door (fwd, port): Height 1.57 m (5 ft 2 in)
Width 0.91 m (3 ft 0 in)
Baggage door (rear): Height 0.90 m (2 ft 113/4 in)
Width 0.72 m (2 ft 41/2 in)
Length, incl galley, lavatory and baggage compartment 13.74 m (45 ft 1 in)
Max width 2.24 m (7 ft 4 in)
Max height 1.88 m (6 ft 2 in)
Floor area 22.9 m2 (247 sq ft)
Volume 43.2 m3 (1,525 cu ft)
Flight deck volume 3.5 m3 (124 cu ft)
Rear baggage compartment volume 4.8 m3 (169 cu ft)
Wings, gross 88.29 m2 (950.4 sq ft)
Ailerons (total, incl tab) 2.68 m2 (28.86 sq ft)
Trailing-edge flaps (total) 11.97 m2 (128.84 sq ft)
Spoilers (total) 7.46 m2 (80.27 sq ft)
Winglets (total) 2.38 m2 (25.60 sq ft)
Fin 10.92 m2 (117.53 sq ft)
Rudder, incl tab 4.16 m2 (44.75 sq ft)
Horizontal tail surfaces (total) 18.83 m2 (202.67 sq ft)
Elevators (total, incl tabs) 5.22 m2 (56.22 sq ft)
Manufacturer's weight empty 16,102 kg (35,500 lb)
Allowance for outfitting 3,175 kg (7,000 lb)
Typical operating weight empty (incl crew):  
G300 19,504 kg (43,000 lb)
G400 19,912 kg (43,900 lb)
Max payload: G300 2,722 kg (6,000 lb)
G400 2,313 kg (5,100 lb)
Payload with max fuel: G300 1,134 kg (2,500 lb)
G400 726 kg (1,600 lb)
Fuel: total: G300 12,249 kg (27,005 lb)
G400 13,429 kg (29,605 lb)
max usable: G300 12,202 kg (26,900 lb)
G400 13,381 kg (29,500 lb)
Max T-O weight: G300 32,658 kg (72,000 lb)
G400 33,838 kg (74,600 lb)
Max ramp weight: G400 34,019 kg (75,000 lb)
Max landing weight 29,937 kg (66,000 lb)
Max zero-fuel weight 22,226 kg (49,000 lb)
Max wing loading: G300 369.9 kg/m2 (75.76 lb/sq ft)
G400 383.2 kg/m2 (78.49 lb/sq ft)
Max power loading: G300 265 kg/kN (2.60 lb/lb st)
G400 275 kg/kN (2.69 lb/lb st)
Max operating speed (VMO/MMO) 340 kt (629 km/h; 391 mph) CAS or M0.88
Max cruising speed at FL310 505 kt (936 km/h; 582 mph) or M0.85
Normal cruising speed at FL450 M0.80 (459 kt; 850 km/h; 528 mph)
Approach speed at max landing weight 149 kt (276 km/h; 172 mph)
Stalling speed at max landing weight:  
wheels and flaps up 130 kt (241 km/h; 150 mph)
wheels and flaps down 115 kt (213 km/h; 133 mph)
Max rate of climb at S/L 1,256 m (4,122 ft)/min
Rate of climb at S/L, OEI 314 m (1,030 ft)/min
Initial cruising altitude 12,500 m (41,000 ft)
Max certified altitude 13,715 m (45,000 ft)
Runway PCN 25
T-O run: G300 1,554 m (5,100 ft)
G400 1,384 m (5,450 ft)
FAA balanced T-O field length at S/L 1,662 m (5,450 ft)
Landing run 973 m (3,190 ft)
Range: with eight passengers and NBAA IFR reserves:  
G300 3,600 n miles (6,667 km; 4,142 miles)
G400 4,100 n miles (7,593 km; 4,718 miles)
Operational noise levels (FAR Pt 36):  
T-O 77.5 EPNdB
Approach 92.0 EPNdB
Sideline 86.6 EPNdB