Quick Look: Gulfstream III

Going the GII one better

August 1, 2012

Gulfstream III

Andrew Gallagher, author of “The Piper Meridian” in the Turbine Pilot section of the July 2012 issue (page T-9), works in sales and training at Santa Monica’s jetAVIVA. We mistakenly reported the company as “jetAvia,” and regret the error.

The Gulfstream III (G-1159A) was developed in the late 1970s as a faster, longer-range successor to Grumman’s original large-cabin business jet, the Gulfstream II. A prototype GIII was rolled out in September 1979 and flew for the first time on December 2, 1979. The FAA certificated the production aircraft on September 22, 1980.

Both the GII and GIII are powered by rear-mounted, 11,400-pound-thrust Rolls-Royce Spey Mk 511-8 engines; however, the newer twinjet incorporates a number of improvements, including a revamped wing, new avionics, extended range, and higher speeds and operating weights. The GIII’s swept wing, which has an integral fuel capacity of 4,400 gallons, is nine feet longer than the GII’s airfoil, is more aerodynamically efficient, and features winglets—all of which combine to reduce drag and improve performance. In fact, the GIII can fly 1,000 nm farther than the GII, giving it an east-to-west transatlantic capability.

The GIII fuselage is nearly four feet longer than the GII, enabling the newer aircraft to typically accommodate between 12 and 19 passengers, plus a crew of two. The GIII also incorporates an improved windshield, a quieter cockpit, and a large (2,200-pound capacity) baggage compartment at the rear of the cabin.

The original GIII cockpit featured Sperry SPZ-800 avionics, along with Collins Pro Line 2 radios. Later-model aircraft were equipped with Honeywell ring-laser gyros, which provided heading reference for aircraft navigation systems, while saving weight and improving gyro reliability. Newer GIIIs have an updated electrical system that weighs 200 pounds less than the system it replaced.

Nearly 20 military and government operators have flown the GIII, including every branch of the U.S. military (under the C–20 designation). One U.S. Air Force C–20 was transferred to NASA’s Dryden Flight Research Center and modified to serve as a testbed for flight research. Other variants included a special reconnaissance and surveillance version (SRA-1), and a maritime reconnaissance and patrol model (SMA-3).

A total of 202 Gulfstream IIIs were built between 1980 and 1987, and about 40 are on the market today. An early model Gulfstream III can cost as little as $800,000, while the average asking price for a late-model GIII is approximately $2.3 million.

A major impediment to the continuing utility of the Gulfstream III is bans on the operation of Stage 2 aircraft in many nations, including the United States after 2015. However, hush kits that make the GIII compliant with Stage 3 noise standards are available from Quiet Technology Aerospace of Opa Locka, Florida, and St. Paul, Minnesota-based Hubbard Aviation Technologies (which has the rights to a noise suppression system originally developed by Stage III Technologies of La Jolla, California). Some 80 GIIIs have been retrofitted with these hush kits.

Robert C. Searles is a writer and editor specializing in commercial, military, and general aviation.


Gulfstream III

  • Engines | Two Rolls-Royce Spey 511-8 turbofans, 11,400 pounds thrust each
  • Seats | up to 19
  • Max takeoff weight | 69,700 pounds
  • Cruise speed | 442 knots
  • Balanced field length | 5,100 feet
  • Range (with IFR reserves) | 3,650 nautical miles
  • Wingspan | 77 feet, 10 inches
  • Length | 83 feet, 1 inch
  • Height | 24 feet, 4 inches