Photograph:
Piper PA-31-310 Navajo VH-WGU (c/n 31-366) at Wagga Wagga, NSW in August 1982 (David C Eyre)
Country of origin:
United States of America
Description:
Business and executive transport
Power Plant:
Two 231 kw (310 hp) Lycoming TIO-540-A six-cylinder horizontally-opposed air-cooled engines
Specifications:
- Wingspan: 12.43 m (40 ft 8 in)
- Length: 9.98 m (32 ft 7½ in)
- Height: 3.96 m (13 ft)
- Wing area: 12.27 m² (229 sq ft)
- Max speed at sea level: 360 km/h (224 mph)
- Max speed at 4,572 m (15,000 ft): 420 km/h (261 mph)
- Cruising speed at 75% power at 1,951 m (6,400 ft): 338 km/h (210 mph)
- Economical cruising speed at 55 % power at 4,459 m (14,600 ft): 314 km/h (195 mph)
- Initial rate of climb: 439 m/min (1,440 ft/min)
- Service ceiling: 6,248 m (20,500 ft)
- Range with normal reserves at 3,048 m (10,000 ft): 2,173 km (1,350 miles)
- Empty weight: 1,634 kg (3,603 lb)
- Loaded weight: 2,812 kg (6,200 lb)
History:
With numerous Piper Apaches and Aztecs having been adapted for commuter airline type work in the early 1960s, it was expected, when Piper unveiled the Navajo as the first of a new breed of twins, variants would be built to meet the needs of the growing commuter market. The prototype Navajo (N3100E) was flown for the first time on 30 September 1964 and was the largest aircraft built by Piper up to that stage. It differed from production aircraft in having three cabin windows on each side, this number being increased to four in the PA-31P Pressurized Navajo, five in the Turbo Navajo, and six in the Navajo Chieftain. The latter became known as the PA-31-350 Chieftain.
The Navajo series was developed following a request by William T Piper for a new large twin-engine aircraft and the project was initially given the name “Inca”. A small number of aircraft were initially built known as the PA-31-3200 with 225 kw (300 hp) engines before production aircraft rolled off the line as the PA-31-310. Deliveries of production machines began in April 1967. The first variants for commuter airlines contained six to eight seats arranged in pairs, thus accommodating a pilot and up to seven passengers, and were powered by two 231 kw (310 hp) Lycoming TIO-540-A six-cylinder engines driving three-blade constant speed propellers, later aircraft receiving the IO-540-K engine. The PA-31-310 received some development during its production life, new models with some changes becoming known as the Navajo B and Navajo C, counter-rotation engines eventually being fitted.
Production of the PA-31 Navajo series concluded in 1983 after 2,044 examples had been built. The type proved very popular in this part of the world and by mid-2012 some 74 examples were still registered in Australia. One successful operator of the type in New South Wales was Hazelton Airlines. The type has been operated in the commuter, charter, air-taxi, light freight, and executive roles.
The type has proved very successful around the world with a range of models being available over the years. It is a low-wing cantilever monoplane of all-metal construction with electrically actuated trailing-edge flaps and a hydraulically actuated tricycle undercarriage.