Defense Advanced Research Projects AgencyTagged Content List

Air Systems

Manned and unmanned aerial systems, including fixed-wing and rotary-wing aircraft and supporting technologies

Showing 135 results for Air RSS
In the early 1980s, DARPA nurtured the development of no-tail-rotor (NOTAR) technologies, resulting in significantly quieter helicopters that could operate with a lower chance of detection. DARPA’s support helped to show the operational advantages of the NOTAR flying demonstrator led to a NOTAR series of helicopters used by government agencies and the commercial sector. The NOTAR system was considered to be the first successful fundamental configuration change to the single-rotor helicopter since the incorporation of the turbine engine in the late 1950s and early 1960s.
| Air | History |
The efficacy of nighttime aerial reconnaissance operations in Southeast Asia was diminished due to engine noise that provided the enemy with advanced warning of approaching aircraft. With an eye on making quiet aircraft that could better serve this reconnaissance mission, ARPA funded the Lockheed Missile and Space Company to develop a quiet, propeller-driven aircraft. This fast-paced program quickly yielded a successful prototype, the QT-2, which in 1968 was deployed and proven in combat. The program transitioned to the U.S. Army, which sponsored a limited production of an advanced version of the quiet aircraft, the YO-3A.
| Air | History |
New materials that perform better than previous ones or with unprecedented properties open pathways to new and improved technologies. F-15 and F-16 fighter aircraft, still in use by the U.S. Air Force today, owe much of their performance advancements to materials technologies that emerged from DARPA materials development programs conducted in the 1970s and early 1980s. One of many notable successes from these efforts was the development of rare-earth permanent magnets with magnetic strengths far stronger than conventional magnetic materials and, in some cases, over larger operational conditions. The samarium- and cobalt-based rare-earth magnetic material Sm2Co17, for example, remains reliable over the entire militarily relevant temperature range of -55°C to 125°C. These magnets ultimately assumed a role in a key component of the AN/ALQ-135 electronic warfare system, permitting operation of the F-15 to 70,000 feet in altitude.

Building on the momentum of jet engine research prior to ARPA’s creation, the Agency joined with the U.S. Army in 1965 on the Individual Mobility System (IMS) project (1965-1969) with the goal of extending the range and endurance of the Bell Rocket Belt developed for the Army in the 1950s. With DARPA funding, Bell replaced the vertical lift rocket system with a compact, highly efficient turbofan engine that Williams Research Corporation was developing.

The DARPA project helped bring the WR-19 turbofan engine into full development. It also brought it to the attention of the U.S. Air Force, for which the engine demonstrated excellent horizontal flight characteristics. The engine was adapted for use in the new Air Force cruise missile program. The U.S. Navy also became interested in the Williams Research engines as it adapted cruise missiles for maritime applications.

By the 1990s, improved versions of the Williams engine would power all the air, surface, and subsurface launched cruise missiles in the Navy and Air Force inventories. Later incarnation of these propulsion technology developments would power the AGM-86B air-launched cruise missiles and Navy Tomahawk cruise missiles in Desert Storm in 1991 and in subsequent conflicts.


The December 1984 test flight of the X-29—the most aerodynamically unstable aircraft ever built—demonstrated forward-swept wing technology for supersonic fighter aircraft for the first time. Technology breakthroughs, among them a digital fly-by-wire flight-control system and carbon-fiber wing technology, made possible a lightweight design far more maneuverable than conventional aircraft. DARPA, NASA, and the U.S. Air Force jointly developed two X-29 technology demonstration aircraft, which the Air Force acquired in March 1985 and used for 279 test flights by April 1990.

Although Air Force fighter designs ultimately embraced DARPA’s stealth revolution rather than the high maneuverability promised by forward-swept wings, other X-29 technologies found their way into future aircraft. Advanced composite materials are now used extensively in military and commercial aircraft. Aeroelastic tailoring to resist twisting under flight loads is now a standard tool for advanced designs with relevant outcomes including the long, thin wings of the Global Hawk, an unmanned surveillance aircraft.