The Gulfstream III, a business jet produced by Gulfstream Aerospace, is an improved variant of the Grumman Gulfstream II.
Design and development
The Gulfstream III was built at Savannah, Georgia in the United States and was designed as an improved variant of the Grumman Gulfstream II. Design studies were performed by Grumman Aerospace Corporation in collaboration withGulfstream American Corporation. Design of the Gulfstream III started with an effort to synthesize a completely new wing employing NASA supercritical airfoil sections and winglets. Optimization studies considering weight, drag, fuel volume, cost, and performance indicated that a substantial portion of the new wing benefit could be secured with modifications to the existing wing. As a result, the new wing concept was canceled and work began on design modifications that would retain the Gulfstream II wing box structure and trailing edge surfaces. The inboard wing was extended in chord and recontoured, to reduce the aircraft’s high-speed drag. The wing span was increased by six feet and five-foot winglets were added. In addition, the fuselage was lengthened by an additional two-foot section aft of the main door and the radome was extended and re-contoured. A new curved windscreen was incorporated, changes were made to the cockpit instruments and autopilot and the maximum take-off weight was increased. The aircraft received type approval from the American Federal Aviation Administration in September 1980.
- Model G-1159A Gulfstream III - Two or three-crew executive, corporate transport aircraft.
- C-20A - United States Air Force variant configured for 14 passengers and 5 crew; phased out of USAF service in 2002, one example transferred to NASA for use at the Dryden Flight Research Center at Edwards Air Force Base as a test aircraft.
- C-20B - United States Air Force and United States Coast Guard variant with upgraded electronics, used for Operational Support Airlift (OSA) and Special Assignment Airlift Missions (SAAM); the single Coast Guard C-20B supports the Commandant of the Coast Guard and other senior USCG officials as well as the Secretary of Homeland Security.
- C-20C - United States Air Force C-20B with upgraded and “hardened” secure communications, often utilized as backup aircraft accompanying the VC-25A aircraft when it is operating as Air Force One
- C-20D - United States Navy Operational Support Airlift (OSA) aircraft with modified communications equipment for use by the Navy, normally in support of high-ranking naval officials
- C-20E - Stretched fuselage/redesigned wing variant for use by the United States Army as an Operational Support Airlift (OSA) aircraft
- Gulfstream III SRA-1 - Special reconnaissance and surveillance version for export.
- Gulfstream III SMA-3 - Export model for Denmark, fitted with a Texas Instruments APS-127 search radar. Three maritime reconnaissance and patrol, fisheries protection, search and rescue, and VIP transport aircraft were built for the Royal Danish Air Force in 1983. No longer in service.
NOTE: United States Army C-20F and C-20J, United States Navy/United States Marine Corps C-20G, and United States Air Force C-20H aircraft are all Gulfstream IV variants.
Special Mission Variants
The NASA Gulfstream III (83-0502 cn 389) has been fitted with a centerline pylon to allow it to carry the UAVSAR pod.
The Phoenix Air Group operates two former Royal Danish Air Force SMA-3 aircraft (N173PA cn 313, N163PA cn 249) and a Gulfstream III (N186PA cn 317). One aircraft provides airborne maritime range surveillance for the Missile Defense Agency (MDA) and other Department of Defense range facilities using a high definition Texas Instruments APS-127 Surface Search Radar system.
N30LX (cn 438) has been modified by the addition of a ventral canoe and sensor turret as the “Dragon Star” Airborne Multi-Intelligence Laboratory for use by Lockheed Martin.
Two Gulfstream IIIs, K2961 (cn 494) and K2962 (cn 495), equipped with long-range oblique photography cameras mounted in the fuselage, were delivered to the Indian Air Force.
- Crew: Two or three
- Capacity: 19 passengers (standard seating)
- Length: 83 ft 1 in (25.32 m)
- Wingspan: 77 ft 10 in (23.72 m)
- Height: 24 ft 4½ in (7.43 m)
- Wing area: 934.6 sq ft (86.83 m²)
- Aspect ratio: 6.0:1
- Empty weight: 38,000 lb (17,236 kg)
- Max. takeoff weight: 69,700 lb (31,615 kg)
- Powerplant: 2 × Rolls-Royce Spey RB.163 Mk 511-8 Turbofan, 11,400 lbf (50.7 kN) each
- Maximum speed: 576 mph (501 knots, 928 km/h) (max cruise)
- Cruise speed: 508 mph (442 knots, 818 km/h) (long range cruise)
- Stall speed: 121 mph (105 knots, 194 km/h)
- Range: 4,200 mi (3,650 nmi, 6,760 km) (eight passengers, IFR reserves)
- Service ceiling: 45,000 ft (13,716 m)
- Rate of climb: 3,800 ft/min (19.3 m/s)