The Gulfstream Aerospace G-1159 Gulfstream III (G-III) was a major step forward in business aviation when it debuted in the late 1970s, bringing better aerodynamics, upgraded avionics, and intercontinental range to the already successful Gulfstream line. Based heavily on the Gulfstream II, it set the stage for future models like the G-IV and G-V.

🛩️ Overview:

• Role: Long-range business jet / executive transport
• Manufacturer: Gulfstream Aerospace (originally Grumman)
• First flight: December 2, 1979
• Introduced: 1980
• Total built: ~202
• Designation: G-1159A
• Developed from: Gulfstream II
• Succeeded by: Gulfstream IV (G-IV)

🛠️ Key Specifications:

• Engines: 2 × Rolls-Royce Spey Mk 511-8 turbofans
• Thrust: 11,400 lbf (50.7 kN) each
• Wingspan: 77 ft 10 in (23.7 m)
• Length: 83 ft 1 in (25.3 m)
• Max speed: Mach 0.85 (approx. 561 mph / 902 km/h)
• Range: ~3,600 nautical miles (6,667 km)
• Service ceiling: 45,000 ft (13,716 m)
• Passengers: Typically 12–19
• Crew: 2–3 + optional flight attendant

✨ Design Features:

• Aerodynamic refinements including extended wing span and winglets (a first for the Gulfstream series)
• Improved range and payload compared to the G-II
• Pressurized cabin with customizable luxury interiors—meeting rooms, beds, galleys, etc.
• Early adoption of digital avionics and flight management systems
• Large oval windows and comfortable standing headroom throughout cabin

🔁 Variants:

🔹 C-20A/B/C/D/E (U.S. Military)

• Gulfstream III variants used by the U.S. Air Force and Army as VIP transports
• Modified with secure communication systems and mission-specific features
• C-20Bs, for example, are used by top-level government and military personnel

🔹 Gulfstream SRA-1

• Special reconnaissance aircraft used by NASA and other organizations for aerial surveillance and research

🛡️ Military & Government Use:

• Widely used by the U.S. military (C-20 series) for high-ranking official transport
• Operated by NASA, NOAA, and foreign governments for research, special missions, and VIP flights
• Some variants modified for surveillance and geophysical missions

🔥 Fun Facts:

• The Gulfstream III was one of the first business jets to be equipped with winglets, which enhanced efficiency and range
• The aircraft was so versatile that it was adapted for use in military, scientific, and diplomatic missions
• The FAA once grounded certain G-III aircraft from operating into some airports due to noise compliance rules—but many were retrofitted with hush kits to meet Stage 3 noise standards

🏁 Legacy:

The G-III was a key transition model between the early-generation Gulfstreams and the more advanced jets that followed. It blended classic reliability with new tech and helped solidify Gulfstream’s position as a leader in large-cabin, long-range jets.

Many G-IIIs are still flying today, particularly in charter fleets, military VIP transport, and airborne research platforms.