The Piper PA-31 Navajo is a family of cabin-class, twin-engine aircraft.

Initial production version, also known unofficially as the PA-31-310.

Variant of the Navajo with normally aspirated engines; 14 built.

Marketing name for 1971 improved variant with 310 hp (231 kW) Lycoming TIO-540-E turbocharged piston engines, new air conditioning and optional pilot access door and optional wide utility door.

Marketing name for 1974 improved variant with 310 hp (231 kW) Lycoming TIO-540-A2C engines and other minor improvements.

Pressurized version of the PA-31 Navajo, powered by two 425 hp (317 kW) Lycoming TIGO-541-E1A piston engines.

Referred to as the Navajo “C/R” for counter-rotating. Variant of Navajo with counter-rotating propellers introduced with the PA-31-350 Chieftain. 325 hp (242 kW) Lycoming TIO-540 / LTIO-540 engines.

Stretched version of the Navajo with more powerful 350 hp (261 kW) engines that rotate in opposite directions (a Lycoming TIO-540 and a Lycoming LTIO-540) to eliminate critical engine issues.

Piston engine variant of the PA-31T1 Cheyenne I; 50 aircraft built.

Also known as the T1020/T-1020; variant of the PA-31-350 Chieftain optimized for commuter airline use, with less baggage and fuel capacity and increased seating capacity (nine passengers). First flight Sept. 25, 1981; 21 built.

Also known as the T1040/T-1040; turboprop powered airliner with fuselage of the PA-31-350T1020, and wings, tail and Pratt & Whitney Canada PT6A-11 engines of PA-31T Cheyenne. First flight July 17, 1981; 24 built.

Experimental version of PA-31-350; two built.

Unbuilt airliner variant with fuselage lengthened by 11 feet, 6 inches (3.51 m) compared to the PA-31-350.

Version of Chieftain built under license by Embraer in Brazil.

Turboprop conversion of EMB 820C, fitted with two Pratt & Whitney Canada PT6A-27 engines flat-rated to 550 shp. The Carajá’s MTOW of 8,003 pounds was 1,000 pounds more than that of the Chieftain.

Re-engined Navajo with 350 hp (261 kW) Lycoming TIO-540-J2B engines, four-blade “Q-Tip” propellers and optional winglets. Conversion designed by Colemill Enterprises of Nashville, Tenn.