X-29, Grumman

X-29 experimental FSW plane Photo by NASA

The two X-29s were built to test a forward-swept wing of composite structure. The X-29 incorporates the forward fuselage of the F-5 and the landing gear of the F-16. It has close-coupled, all-moving canards. The X-29s made 374 flights, before they were put in storage.

Two X-29As were built by Grumman Aerospace Corporation, the first flight taking place in 1984. The aircraft were adapted from existing Northrop F-5A Freedom Fighter airframes (after the airframe had been chosen over a competing proposal involving a General Dynamics F-16 Fighting Falcon); the modified design was known internally as the G-712. The test program of the two planes continued for over a decade, and on December 13, 1985 one of them became the first forward swept wing aircraft to fly supersonically in level flight (the earlier Junkers Ju 287 had been the first jet aircraft with forward-swept wings). Though similar in overall concept to the Russian SU-47 Berkut research aircraft of the late 1990s, the later is about twice the size and far closer to an actual combat aircraft than the US design.

effects reverse airflow on X-29 aircraft The X-29A demonstrated excellent control and maneuvering qualities at an angle of attack up to 45 degrees. There was also a decrease in turbulence. The wing configuration made the craft inherently unstable. It could fly only with the constant corrections (up to 40 per second) provided by the computerized flight control system. The system was made up of three redundant digital computers backed up by three redundant analog computers.

The picture on the left shows the reverse airflow-forward-swept wing vs aft swept wing. On the forward-swept wing, ailerons remained unstalled at high angles of attack because the air over the forward swept wing tended to flow inward toward the root of the wing rather than outward toward the wing tip as on an aft-swept wing. This provided better airflow over the ailerons and prevented stalling (loss of lift) at high angles of attack.

The first craft built is now on display in the National Museum of the United States Air Force at Wright-Patterson Air Force Base near Dayton, Ohio.

Type: X-29
Country: USA
Contructor : Grumman Aerospace Corporation
Function: experimental
Year: 1984
Crew: 1
Engines: 1 * 71.2kN G.E. F404-GE-400
Wing Span: 8.80 m
Length: 14.7 m
Height: 4.36m
Wing Area: 17.54 m2
Empty Weight: 6260 kg
Max.Weight: 8074 kg
Speed: Mach 1.46
Ceiling: 15200 m
Rate of climb: ? m/min
Range: ? km

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