The Associated Air Liberty 181 is a niche, low-production homebuilt aircraft designed specifically for bush operations. Introduced in the late 1990s by Associated Air, based in Woodland, Washington, the aircraft was marketed as a kit for amateur construction. The design focuses on utility and short-field performance, intended to transport heavy loads into rugged, unprepared environments. By 1998, the manufacturer reported that seven kits had been sold, with only one aircraft completed and flying at that time.
Designed as a four-seat utility aircraft, the Liberty 181 features a strut-braced high wing and a fixed conventional landing gear arrangement (tailwheel). The enclosed cabin is designed to accommodate one crew member and three passengers. To support long-range operations in remote areas, the aircraft is equipped with a substantial fuel capacity of 100 U.S. gallons (380 L). Its structural specifications include an empty weight of 1,890 lb (857 kg) and a maximum gross weight of 3,200 lb (1,451 kg).
Power is provided by a single Continental O-470 engine, a six-cylinder, air-cooled, four-stroke horizontally-opposed piston engine producing 230 hp (170 kW). This engine drives a two-bladed constant-speed propeller. The aircraft's performance is characterized by a very low stall speed of 38 mph (61 km/h) with flaps deployed, a cruise speed of 130 mph (210 km/h), and a rate of climb of 2,000 ft/min. Its service ceiling is listed at 22,050 ft, and it possesses a maximum range of 1,200 miles. Notably, technical references list a maximum speed of 90 mph, which is lower than the stated cruise speed.
Due to its nature as a kitplane, the Liberty 181 has seen very limited service. There is no record of military use. Civil operations are restricted to private owners. As of October 2016, no examples were registered with the FAA in the United States, although one aircraft built in the U.S. in 1996 was exported to Canada and appeared on the Transport Canada registry in 2008. The aircraft remains a rare example of late-20th-century amateur-built utility aircraft designed to compete with certified bush planes.