X-26 Frigate

The X-26 is a sailplane and is the longest-lived of the X-plane programs.

Development

The X-26A was used by the U.S. Navy (USN) to train test pilots in the condition of yaw/roll coupling. Since jet trainers were known to be dangerous in this condition, the X-26 was based on the Schweizer SGS 2–32 sailplane. Sailplanes react much slower and are easier to control than jet aircraft, making the X-26 a much safer training platform. Four aircraft were originally ordered. Three of the original planes crashed. The USN purchased a replacement for each of the crashed units.

Operational History

The X-26B were X-26As modified with a Continental O-200A engine and propeller. These aircraft were designed to test stealth observation techniques for aircraft during the Vietnam War. Two of the X-26As were modified for the program. They were tested in Vietnam successfully. The Lockheed YO-3A Quiet Star program continued the research begun by the X-26B. After the completion of their part of the program, the X-26Bs were de-modified and returned to the USN.

The USN continues to use the X-26A in the training program at the U.S. Naval Test Pilot School.

Specifications (X-26A Frigate)

General Characteristics

Crew: two
Length: 26 ft 9 in (7.92 m)
Wingspan: 57 ft 1.5 in (17.37 m)
Height: 9 ft 3 in (2.74 m)
Wing area: 180 ft² (16.72 m²)
Aspect ratio: 18:1
Empty: 857 lb (389.55 kg)
Loaded: 1430 lb (650 kg)
Maximum takeoff: lb ( kg)

Performance

Maximum speed: 158 mph (254.38 km/h)
Maximum glide ratio:
Rate of sink: 36 m/min (120 ft/min)
Wing loading: 36 kg/m² (7 lb/ft²)

References

American X-Vehicles (.pdf)