G-III Aerodynamics Research Test Bed

NASA Dryden Flight Research Center operates a Gulfstream G-III aircraft, NASA tail 

number 804, as an aerodynamics research test 

bed. 

Work with the aircraft is funded through 

NASA’s Aeronautics Research Mission 

Directorate as part of the Environmentally 

Responsible Aviation, or ERA project under 

the agency’s Integrated Systems Research 

Program.

The directorate is leading the push to validate 

technologies that have matured through foundational research to a point that merits evaluation at the systems level – including flight 

test at NASA Dryden. The goal is to explore 

environmentally friendly aircraft concepts for 

the future.

Adaptive Compliant Trailing Edge Flight 

Experiment

One experimental project is currently under 

way with the aircraft, the Adaptive Compliant Trailing Edge, or ACTE, project, a joint 

effort between NASA and the U.S. Air Force 

Research Laboratory.

In the ACTE project, both of the G-III’s conventional 19-foot-long aluminum flaps will 

be replaced with advanced, shape-changing 

flaps that form continuous bendable surfaces. 

The flexible flaps are made of composite materials to a patented design from FlexSys, Inc.

When conventional flaps are moved, gaps exist between the forward edge and sides of the 

flaps and the wing surface. The ACTE flaps 

The Active Compliant Trailing Edge (ACTE) project will replace both of the G-III’s conventional 19-footlong aluminum flaps with advanced, shape-changing composite-material flaps that form continuous 

bendable surfaces. (NASA / Tony Landis)
FS-2012-03-103 DFRC

National Aeronautics and Space Administration

Dryden Flight Research Center

P.O. Box 273

Edwards, California 93523

NASA Facts

will be gapless, forming a seamless transitionregion with 

the wing while remaining attached at the forward edge 

and sides. The improved flap should eliminate a major 

source of airframe noise generation.

If successful, thisexperiment will enable aircraft using 

such flaps to be significantly quieter during takeoff, approach and landing.

Aircraft Description

The Gulfstream III was built by Gulfstream Aerospace 

Corp. In commercial versions, the G-III’s basic role is 

that of an executive business aircraft capable of carrying 

up to 12 passengers. The C-20B version currently flown 

by the Air Force serves in a similar capacity for highlevel government and military officials.

Built in 1982 and carrying serial number 344, NASA’s 

G-III No. 804 was previously owned and operated by the 

U.S. Department of Energy and acquired by NASA in 

late 2009. NASA’s Aeronautics Research Mission Directorate provided 75 percent of the $2 million acquisition 

cost, while the Air Force Research Laboratory provided 

the remaining 25 percent.

The G-III’s maximum takeoff weight with full fuel and 

passengers/cargo is 69,700 lbs. Empty, the unmodified 

airplane weighs about 38,000 lbs. It has a wingspan of 

more than 77 feet, is about 83 feet long and just over 

24 feet high. Average cruising speed for the aircraft is 

495 mph (430 knots) and its top speed is 581 mph (505 

knots/Mach 0.85) at 28,000 feet. Maximum operating 

altitude is 45,000 feet. Fully loaded, the Gulfstream III 

has a range of about 4,000 nautical miles (4,600 statute 

miles).

Two Rolls-Royce Spey Mark 511-8 turbofan engines 

power the aircraft. Each engine produces 11,400 pounds 

(5,170 kg) of thrust.

FlexSys ACTE flap technology bridges gaps in wing for a 

seamless surface. (Flexsys image)

Gulfstream III three-view graphic. 

(NASA graphic)