Gulfstream IV

The Gulfstream IV (or G-IV or GIV) and derivatives are a family of twin-jet aircraft, mainly for private or business use. The aircraft was designed and built by Gulfstream Aerospace, a General Dynamics company based in Savannah, Georgia, United States from 1985 until 2003.

Design and development
Gulfstream, in collaboration with Grumman, began work on the Gulfstream IV in March 1983 as a re-engined, stretched fuselage derivative of the Gulfstream III. A decision to redesign the wing structure for weight reduction presented an opportunity for an aerodynamic redesign of the wing to reduce cruise drag and increase range. Wing contour modifications had to be restricted to the forward 65% of wing chord so that no redesign of the control surfaces would be necessary. Modification of the inboard wing would have entailed a redesign of the fuselage floor structure, consequently this region of the wing was not modified. Outboard wing modifications were aimed at reducing the peak subcritical pressure coefficient and moving it aft in an effort to reduce shock strength and increase shock sweep. The Gulfstream IV wing has a weaker, more swept outboard shock resulting in a lower cruise drag. Other benefits arising from this design are a lower root bending moment due to the more inboard center of pressure, a lower stall speed due to washout and a larger fuel volume due to increased chord. These aerodynamic improvements result in an increase in range of over 300 nautical miles.

The first GIV made its maiden flight on September 19, 1985. The model received type certification from the FAA in April 1987. The G-IV entered into service with serial number 1000 in 1987 and was upgraded to the special purpose GIV-SP version at serial number 1214 in 1993. It was later redesignated G400 at serial number 1500.



A shorter range variant was created based on the GIV and given the G300 designation in 2002. The G400 has a large cabin, long range of 4,350 nautical miles (8,060 km) and the same comfort and design that characterize the G series. Typical cruise height and speed are 45,000 ft and Mach 0.88. Earlier models were fitted with Honeywell's SPZ 8000 Avionics package. The SPZ 8400 Avionics Package was an option, becoming standard on later models. It costs about $15 million at 2009 prices.

In 2001 Gulfstream began work on an improved version of the GIV-SP, originally designated GIV-X. It was later renamed G450. The G450 is lengthened 1 ft (0.305 m) over the G400 and shares the forward fuselage and larger cockpit of the G550. Production of the G450 began in October 2004, replacing the G400. The G450 has better performance and comes with the PlaneView cockpit with four 14 in (355 mm) liquid crystal displays and a Head up display (HUD). The shorter range G350 version of the G450 was developed and received certification in 2004.

Operational history
The National Oceanic and Atmospheric Administration (NOAA) operates a GIV-SP (N49RF) modified to fly scientists and crew members at 45,000 feet around tropical cyclones. The aircraft was modified to drop instruments called "dropsondes" to measure windspeed, barometric pressure, humidity, and temperature as they fall to the surface of the ocean. By sampling the cyclone with these dropsondes over a 4,000 mile track around the storm, the forecasters at NOAA's National Hurricane Center and Hurricane Research Division can better predict where the hurricane will be "steered" by the upper level winds. They also predict wind shear that will either increase or decrease a hurricane's strength. The GIV-SP is suited for this mission since it is fast, and can fly long distances with ample cabin space for the crew and instruments. In 2009, the NOAA GIV-SP was further modified by the addition of a side-scanning Doppler radar to the rear fuselage. This radar is used for storm cloud profiling.

In June 1987 a Gulfstream IV set 22 world records in its class in flying west around the world in 45 hr 25 min. The next year another GIV set 11 world records flying east around the world. In 1990, Gulfstream CEO Allen Paulson and a Gulfstream flight crew set 35 international records for around-the-world flight in a GIV.

C-20F/G/H/J military variants
The U.S. military variant of the IV, designated C-20F/G/H/J Gulfstream IV in Department of Defense service. The C-20F is a GIV model operated by the U.S. Army in a command/executive transport role.

The C-20G aircraft may be configured for cargo operations, 26 passenger operations or combinations of the two. With passengers seats removed, it may be configured as three pallets with no passengers or two pallets and eight passengers or one pallet and fourteen passengers. With full seating, the aircraft is capable of accommodating up to twenty-six passengers and a crew of four. A hydraulically operated cargo door is installed on the starboard side of the aircraft, and a ball roller cargo floor is capable of accommodating palletized cargo. The C-20G is operated by Fleet Logistics Support Squadron Four Eight (VR-48) at Naval Air Facility, Andrews Air Force Base, Washington, DC and at VMR Detachment Kaneohe Bay, Marine Corps Air Station Kaneohe Bay, Marine Corps Base Hawaii.

The C-20H is a GIV-SP model operated by the U.S. Air Force in a command/executive transport role. The C-20J is a GIV-SP model operated by the U.S. Army in a command/executive transport role.

G350/G450
The G450 is an improved version of the GIV-SP/G400 using technologies from the G500/G550 (an upgrade to the GV). It has a "PlaneView" cockpit with 4 Honeywell 21 EFIS screens, and a Gulfstream-designed cursor control system. It also has the "Enhanced Vision System" (EVS), an infrared camera that displays an image of the view in front of the camera on a head up display. EVS permits the aircraft to land in lower-visibility instrument meteorological conditions than a non-EVS-equipped aircraft. Another exterior difference between the G-IV and G450 is the removal of windshield wipers on the G450.

The G350 is the short-range version of the G450. It has the same exterior appearance as G450, and includes the PlaneView cockpit, but does not have EVS as standard equipment, which is available as an option.

Civil operators
The aircraft is operated by private individuals, companies and executive charter operators, and in fractional ownership programs.

Government and military operators

 * The Botswana Air Force operates a single G-IV for VIP transport.
 * The Sultan of Brunei operates a G-IV.
 * The Chilean Air Force operates one G-IVs in a commander / executive transport role.
 * Côte d'Ivoire Air Force as a VIP transport.
 * The Egyptian Air Force operates four G-IVs in a commander / executive transport role.
 * The Indian Air Force in Reconnaissance Role.
 * The Irish Air Corps operates a G-IV for government transport at an average cost per hour in 2012 of €3,790.
 * Royal Jordanian Air Force operates 3 G-450 For VIP transport.
 * The Japan Air Self-Defense Force operates five G-IVs under the designation U-4, modified to incorporate a large cargo door and can move palletized cargo and passenger mixes similar to the C-20G aircraft operated by the U.S. Navy and Marines.
 * The Sultan of Johor operates a G-IV.
 * The Mexican Navy uses a G-450 for government / VIP transport.
 * The Royal Netherlands Air Force operates one G-IV SP in a commander / government transport role.
 * The Royal Saudi Air Force operates one G-IV in a commander / government transport role. The military operates two G-IVs SP and two G450s in the med/vac transport role.  The Saudi Arabian Minister of Finance and Economy operates a G-IV (G300). Saudi Arabian Airlines operates 6 G-IVs for government use. Saudi Aramco - 3 G450.
 * The Swedish Air Force operates four Gulfstream IVs, two are modified G-IV SPs in the SIGINT role and are designated S 102B Korpen (Raven). Two other aircraft, a G-IV designated TP 102A, and a G-IV SP, designated TP 102C, serve as transport for the Royal Family and the Prime Minister.
 * Royal Jordanian Air Force operates 3 G-450 For VIP transport.
 * The Japan Air Self-Defense Force operates five G-IVs under the designation U-4, modified to incorporate a large cargo door and can move palletized cargo and passenger mixes similar to the C-20G aircraft operated by the U.S. Navy and Marines.
 * The Sultan of Johor operates a G-IV.
 * The Mexican Navy uses a G-450 for government / VIP transport.
 * The Royal Netherlands Air Force operates one G-IV SP in a commander / government transport role.
 * The Royal Saudi Air Force operates one G-IV in a commander / government transport role. The military operates two G-IVs SP and two G450s in the med/vac transport role.  The Saudi Arabian Minister of Finance and Economy operates a G-IV (G300). Saudi Arabian Airlines operates 6 G-IVs for government use. Saudi Aramco - 3 G450.
 * The Swedish Air Force operates four Gulfstream IVs, two are modified G-IV SPs in the SIGINT role and are designated S 102B Korpen (Raven). Two other aircraft, a G-IV designated TP 102A, and a G-IV SP, designated TP 102C, serve as transport for the Royal Family and the Prime Minister.
 * The Mexican Navy uses a G-450 for government / VIP transport.
 * The Royal Netherlands Air Force operates one G-IV SP in a commander / government transport role.
 * The Royal Saudi Air Force operates one G-IV in a commander / government transport role. The military operates two G-IVs SP and two G450s in the med/vac transport role.  The Saudi Arabian Minister of Finance and Economy operates a G-IV (G300). Saudi Arabian Airlines operates 6 G-IVs for government use. Saudi Aramco - 3 G450.
 * The Swedish Air Force operates four Gulfstream IVs, two are modified G-IV SPs in the SIGINT role and are designated S 102B Korpen (Raven). Two other aircraft, a G-IV designated TP 102A, and a G-IV SP, designated TP 102C, serve as transport for the Royal Family and the Prime Minister.
 * The Royal Saudi Air Force operates one G-IV in a commander / government transport role. The military operates two G-IVs SP and two G450s in the med/vac transport role.  The Saudi Arabian Minister of Finance and Economy operates a G-IV (G300). Saudi Arabian Airlines operates 6 G-IVs for government use. Saudi Aramco - 3 G450.
 * The Swedish Air Force operates four Gulfstream IVs, two are modified G-IV SPs in the SIGINT role and are designated S 102B Korpen (Raven). Two other aircraft, a G-IV designated TP 102A, and a G-IV SP, designated TP 102C, serve as transport for the Royal Family and the Prime Minister.
 * The Swedish Air Force operates four Gulfstream IVs, two are modified G-IV SPs in the SIGINT role and are designated S 102B Korpen (Raven). Two other aircraft, a G-IV designated TP 102A, and a G-IV SP, designated TP 102C, serve as transport for the Royal Family and the Prime Minister.
 * The Turkish Air Force operates a G-IV SP in a commander / executive transport role.
 * The Pakistan Air Force operates four G-IV SPs in a commander / executive transport roles.
 * The Pakistan Air Force operates four G-IV SPs in a commander / executive transport roles.
 * The Pakistan Air Force operates four G-IV SPs in a commander / executive transport roles.

The Government of Uganda purchased one G-IV in December 2000 at a cost of US$31.5 million for Presidential flights. It was sold in December 2009.


 * United States Air Force as C-20 series
 * United States Army as C-20 series
 * United States Navy as C-20 series
 * United States Marine Corps as C-20 series
 * NOAA - operates a G-IV-SP in an atmospheric research and hurricane tracking role.
 * NOAA - operates a G-IV-SP in an atmospheric research and hurricane tracking role.


 * The Venezuelan Air Force operates a G-IV in a commander / executive transport role.
 * The Venezuelan Air Force operates a G-IV in a commander / executive transport role.

Specifications
Sources: Frawley, Gulfstream G450 page, Gulfstream G350 page