The Gulfstream III was built around a clear idea: take the proven Gulfstream II and make it go farther, faster and higher without giving up the large cabin.

Gulfstream's own history records the first flight on December 2, 1979, with entry into service in late 1980. The company says the GIII reached 3,600 nm and introduced a new wing with greater span and winglets. More than 200 were sold between 1980 and 1987. AOPA records 202 completed aircraft.

The engineering work went well beyond adding winglets. The GIII received a redesigned wing, greater fuel capacity, a longer fuselage, new avionics and higher operating weights. The FAA's current type-rating material identifies the civil G-1159A and its military C-20A through C-20E equivalents under the G-1159 type rating.

Then came a remarkable demonstration of what the design could do. In November 1983, a Gulfstream III became the first business jet to fly over both the North and South Poles.

That was not a marketing exercise. The aircraft had enough range and endurance to make the idea practical.

• The GIII has a real government and special-mission history:

The U.S. military did not treat the GIII as just another executive transport. The C-20B was used for special air and operational support missions, while the U.S. Navy operated the C-20D for worldwide passenger airlift. The Coast Guard also operated a C-20B as its dedicated command and control support aircraft until 2002.
NASA later pushed the same airframe much harder.
NASA's GIII fleet has been used for atmospheric research, radar work, aerodynamic testing and sensor missions. One NASA GIII was acquired from the Department of Energy before becoming a research testbed.

• The cockpit can be very old, or heavily modified:

The original GIII cockpit used Sperry SPZ-800 avionics with Collins Pro Line 2 radios. Individual aircraft have since received very different equipment packages. Current and former aircraft listings show combinations including Universal UNS-1D and UNS-1C FMS units, Honeywell EFIS, Collins navigation equipment, TCAS and modernized multifunction displays.
So I would not evaluate a GIII from its model year alone. The avionics specification of the actual aircraft can change the ownership proposition considerably.

• Noise compliance is a buying issue, not a footnote:

Stage 2 restrictions became one of the biggest problems for older GIIIs. AOPA reported that roughly 80 GIIIs had received hush kits, while NASA currently documents GIIIs equipped with hush kits that allow Stage III compliant operations.
NASA's 2026 maintenance documentation is even more revealing. Its 72-month inspection work includes specific inspections of winglet attachment hardware and hush-kit thrust reverser components.
For an international operator, this deserves checking before the aircraft ever reaches the pre-purchase inspection.

Dassault Falcon 50 for sale:
Range: 3,000 to 3,200 nm / Passengers: Typically 8 to 9.
The Falcon 50 is the logical comparison when runway performance matters. Its three-engine layout, leading-edge slats and large flaps give it strong short-field and hot-and-high capability. The GIII counters with a larger airframe and more cabin space.

Bombardier Challenger 601-3R for sale:
Range: 3,430 nm / Passengers: Up to 19.
This is one of the closest period competitors. The Challenger carries a similar number of passengers and reaches a similar range, but its 43,100 lb MTOW is far below the GIII's 69,700 lb. The Gulfstream is the larger airplane by a substantial margin.

Dassault Falcon 900B for sale:
Range: 3,800 nm for the original 900 and about 4,000 nm for the 900B.
Dassault developed the Falcon 900 specifically to compete in the same market as the Challenger 601 and Gulfstream III. Three engines, strong runway performance and later range improvements are its main differences.

Gulfstream IV for sale:
Range: 4,200 nm.
The GIV is the natural Gulfstream upgrade. Gulfstream's history records a first flight in 1985 and entry into service in 1987, while the GIV introduced a larger wing and substantially more range. Production of the GIV family eventually reached 500 aircraft.
If the mission regularly pushes beyond the GIII's range, the GIV is the more logical place to look.

Cessna Citation III for sale:
Range: Roughly 1,950 to 2,090 nm / Passengers: Up to 11.
The Citation III is a much smaller aircraft. It is fast and has a respectable stand-up cabin, but its range and cabin volume put it in a different mission category. AOPA notes that the lack of transcontinental range was one reason the Citation III eventually disappeared from the market.

The GIII is at its best when the mission calls for a large cabin, a substantial passenger load and roughly 3,000 to 3,600 nm of range.

Take eight passengers on a transatlantic mission. The published range puts that type of trip within the aircraft's historical operating envelope, but the actual answer depends on payload, winds, reserves, runway conditions and the individual aircraft. NASA's N992NA is documented at 3,650 nm with eight passengers and three aircrew.

It also remains useful for special missions. NASA's GIIIs have carried research equipment, radar systems, dropsondes and other instrumentation. One Langley aircraft has a 4,500 lb useful payload and a 3,000 nm stated range in its current research configuration.

Airport access is a different question.

The GIII is a 69,700 lb airplane. The U.S. Army Corps of Engineers lists a 5,450 ft takeoff distance for the C-20A/B/C/D group under its published aircraft characteristics, while AOPA lists a 5,100 ft balanced field length for the civil GIII. Actual performance remains dependent on conditions and weight.

The Gulfstream III is not an old jet pretending to be new. It is a large, heavy, long-range business aircraft from another generation that still has a clear job.

Its strongest cards are the large cabin, roughly 3,650 nm published IFR range, 45,000 ft ceiling and an airframe proven in corporate, military, government and research work.

Looking for a Gulfstream III for Sale?
Give us the mission first:

• How many passengers?
• Which routes?
• How much range do you need?
• What year or configuration do you prefer?
• What are your requirements for engines, maintenance and avionics?
• Where will the aircraft be registered and operated?

We will search the open market and our off-market network and come back with aircraft that fit the requirement.