The Piper PA-31 Navajo was designed and produced by Piper Aircraft as a series of cabin-class twin-engined aircraft intended for the general aviation market. The aircraft was usually powered by Lycoming engines and was also license-built in some countries in Latin America. The Navajo was introduced on March 30, 1967, and was produced from 1967 to 1984 with a total number of 3,942 aircraft built.
The Piper PA-31 Navajo was built upon the request of William T. Piper in 1962 to build a six to eight-seat corporate and commuter aircraft powered by two Lycoming engines. The development was given the project name Inca. During late 1964, the aircraft designated as PA-31 was officially introduced after its maiden flight on September 30, 1964. The Pa-31 Navajo was produced from 1967 to 1984 with a total number of 3,942 aircraft built.
The Piper Pa-31 Navajo can accommodate one or two crew and five to seven passengers on board. It has an external length of 9.94 meters, an external height of 2.3 meters, and a fuselage diameter of 1.35 meters. The low-wing monoplane has a wingspan of 12.4 meters and a wing area of 21.3 square meters. It has a conventional tail with a height of 3.96 meters and a wheelbase of 3 meters. The cabin height is 1.3 meters, the cabin width is 1.27 meters and the cabin length is 3.27 meters.
The civil utility aircraft is powered by two Lycoming TIO-540-A engines. It is a turbocharged, fuel-injected, air-cooled, horizontally-opposed piston engine that produces a maximum takeoff thrust of 310 horsepower each and drives three0bladed Hartzell metal, fully feathering propellers of 2.03 in diameter. The PA-31 Navajo has an empty weight of 1,783 kg, a maximum payload of 1,100 kg, and a maximum takeoff weight of 2,948 kg. The total fuel tank capacity is 190 US gal and the useable fuel is 187 US gal.
The Piper PA-31 Navajo has a maximum speed of 227 knots at 15,000 feet. It has a cruise speed of 207 knots at 20,000 feet, a stall speed of 63 knots with flaps down, and a never exceed speed of 236 knots. The travel range is 1,012 nautical miles at 20,000 feet. The aircraft can fly up to 26,000 feet and can climb at a rate of 1,445 feet per minute.