SCALED COMPOSITES MODEL 326 « PEGASUS » (NORTHROP GRUMMAN X-47A)
Developed to the same specifications as Boeing's X-45, this UAV heralded the future of fighters to come...




The X-47A on its first flight at China Lake in February 2003.




Another view of the X-47A's first flight, with open landing gear.

USAF / USN designation: X-47A
DARPA Program: J-UCAS (Joint Unmanned Combat Air Systems)

Type:  

Program:  

Powerplant: 1 x 3,190 lb. Pratt & Whitney JT15D-5C-TF

First flight: 23 February 2003

The goal of the joint DARPA/Navy Unmanned Combat Air Vehicle (UCAV-N) program was to demonstrate the technical feasibility for an unmanned system to effectively and affordably conduct sea-based surveillance, strike and suppression of enemy air defenses missions within the emerging global command and control architecture. The X-47A Pegasus program plays a significant role in supporting this effort. Northrop Grumman designed and built the Pegasus with its own funds to demonstrate low-cost, rapid prototyping; robust unmanned vehicle management; and tailless aerodynamic qualities suitable for autonomous launch and recovery flight operations from an aircraft carrier. Another alleged goal of the X-47A is to significantly reduce the risk for DARPA and Navy on the Unmanned Combat Air Vehicle program.

The Pegasus was designed in El Segundo at the Air Combat Systems business area of Northrop Grumman Integrated Systems. The vehicle is powered by a Pratt & Whitney JT15D-5C engine providing 3,200 pounds of thrust, and was built at Scaled Composites in Mojave, Calif., largely with composite materials. Although the airframe was a Northrop Grumman design, the fruit of 10 years of internal R&D work, Program Manager David Mazur Mazur went to Burt Rutan’s famed Scaled Composites shop in Mojave, Calif., for the fabrication. Mazur says composites offered a quick build time, and few or no fasteners on the exterior—a must for stealth. Northrop Grumman colocated seven engineers at Scaled, working in the same hangar where the Pegasus was being built. “Guys were taking our designs, making drawings, and taking them right to the [production] technicians,” Mazur says. At the time, the program was referred to by the code name “Vaun” under a system the company uses so that workers can discuss a project without letting the public in on the secret. The name comes from the first letters of Northrop Grumman unmanned aerial vehicle, in reverse, says Mazur. Scaled completed the work on schedule, in 12 months and 12 days.

In June 2001, the Pegasus received the official DoD designation X-47A, while the projected Navy production version received the designation X-47B. On July 30, The X-47A was rolled out of a hangar in Mojave, Calif., at a celebration for employees, while a full-scale model of the aircraft was displayed at NAS Patuxent River for the Air Demonstration 2001. From Aug. 24, the model was put on display at NAS Patuxent's Naval Air Museum. The first flight of the X-47A took place at NAVAIR Weapons Division, China Lake, Calif. on Feb. 23, 2003. Specific test objectives included low-speed handling qualities, air vehicle performance, navigation performance and collection of landing dispersion data. All test objectives were met. Pegasus measures 27.9 feet long with a nearly equal wingspan of 27.8 feet. It incorporates advanced autonomous flight control laws to account for directional control of its tailless design. The design builds upon the experience that Northrop Grumman (notably through its Teledyne Ryan branch) has accumulated through thousands of hours of autonomous flight by unmanned systems such as Global Hawk and Fire Scout. Pegasus is a logical progression in repeatable performance with a complex aerodynamic shape.

In April 2003, DARPA combined the UCAV-N program with the on-going USAF/DARPA UCAV program into the joint DARPA/USAF/Navy J-UCAV program, later renamed J-UCAS (Joint Unmanned Combat Air Systems). Northrop Grumman apparently decided that further flight tests of the X-47A would not help the development of its forthcoming J-UCAS demonstrator, designated X-47B. Most significantly, the X-47A successfully landed near a predesignated touchdown point to simulate the tailhook arrestment point on a carrier flight deck. This landing data, coupled with subsequent flight touchdown points, will demonstrate the X-47A system's landing accuracy potential. As regular unmanned flight operations aboard a flight deck at sea have never been attempted, lessons learned from the development and testing of Pegasus will therefore benefit the U.S. Navy; however, the US Air Force has also shown interest in the X-47 design and the J-UCAS (Joint Unmanned Combat Air Systems) program has now superseded the strictly naval DARPA/Navy UCAV-N program. The shipboard-relative global positioning satellite system was used as the primary navigation source for increased landing precision. This success points to the potential for joint use of the Pegasus design to meet Air Force requirements in the government's emerging Joint UCAV program.


Population: 1 (no known registration)

Specs:
Length: 27.9 ft.
Wingspan: 27.8 ft.
Fuselage height: 6.1 ft.
Tail height: 5.7 ft.
Tread: 9.9. ft.
Wheelbase: 10.1 ft.
Leading edge sweep: 55°
Trailing edge sweep: 30°
Gross weight: 5,500 lbs.
Payload weight: 1,000 lbs.
Fuel Capacity: 1,580 lbs. (1,040 lbs. mission)
Structure: composite/aluminum
Guidance: navigation (GPS/INS)
Speed: subsonic

Crew/passengers: unmanned

Main sources:
- Northrop Grumman's official website
- UAV forum

Artist's concept of a production X-47A aircraft for the Navy.
The planned X-47BN Navy version is quite different from this.