Pratt & Whitney Canada PT6 is a turboprop aircraft engine manufactured by Pratt & Whitney Canada, a subsidiary of the American corporation Pratt & Whitney . It is one of the most widespread theater of its class in the world: the total release by November 2015 amounted to 51,000 copies, the total operating time - 400 million flight hours. The main application of the engine is light passenger, transport and training aircraft, such as the Cessna 208 , DHC-6 Twin Otter , Beechcraft King Air , Short 360 and many others. PT6 modifications are used on helicopters, as well as on ships, hovercraft, and ground equipment. On the basis of this engine, auxiliary power plants and industrial gas turbines were also developed.
Content
- 1 Development
- 2 Design
- 3 Modifications
- 4 See also
- 5 notes
- 6 References
Development
The design of the engine dates back to 1956. At that time, the main commercially successful model of the company was a Wasp piston star engine with a power of 600 hp. Despite its large-scale serial production, the management of Pratt & Whitney Canada foresaw the need for a theater of similar power. However, the Commercial Bank of Montreal refused to finance the project, but despite this, the first prototype engine was manufactured during 1959 [1] . The first flight took place in 1961, and certification and launch into production in 1963. Since that time, the characteristics of the PT6 have been constantly improving: in the versions released for 2016, the thrust to weight ratio increased by 50% compared to the earlier series, fuel consumption decreased by 20%, and the compression ratio reached 14: 1. In the process of modernization, the management system was also improved, the overhaul interval was expanded and environmental indicators improved. Currently, EngineWise platform is collecting and analyzing data from operated PT6s remotely, and for the convenience of operators, the manufacturer has developed a mobile application that informs them of the necessary service bulletins, service instructions and the availability of repair centers separately for the type of engine registered by the user [2] .
Design
PT6 is a free turbine gas turbine engine. The diagram is the opposite of the direction of flight (the air intake at the rear, the gearbox and the exhaust in front), which is a convenient solution for driving a propeller or fan, as well as to simplify maintenance. Around the rear of the engine there is a radial type input device, a mesh is installed in it to protect against ingress of foreign objects, there is an anti-icing system based on alcohol injection. Further, the air enters the compressor, which has 3 or 4 (on versions of greater power) axial stages and 1 centrifugal. The compressor and diffuser housing is made of stainless steel. The combustion chamber is an annular countercurrent with 14 single-stage nozzles, its body is also made of stainless steel. The compressor turbine is single-stage with a maximum rotation speed of 45,000 rpm. It is gasdynamically coupled to a power turbine, one- or two-stage on more powerful modifications, rotating at a speed of 30,000 rpm. To drive the propeller (clockwise), a two-stage gearbox is used, reducing the speed to 1900-2200 rpm. Behind it on the sides are 2 exhaust pipes [3] [4] .
Modifications
The PT6 family is mainly represented by modifications to the PT6A for installation on aircraft, as well as turboshaft helicopter options PT6B / C. There are various specialized versions of the engine for ground, industrial and other applications.
| Modification | Horsepower | Application |
|---|---|---|
| PT6A series | ||
| PT6A-6 | 500 | basic version |
| PT6A-112 | 500 | Cessna F406 , Cessna Conquest I |
| PT6A-11 | 550 | |
| PT6A-114A | 675 | Cessna 208 |
| PT6A-27 | 680 | DHC-6 series 300, Embraer EMB 110 , Beechcraft 99 , LET L410 , Pilatus PC-6 Turbo Porter |
| PT6A-135A | 750 | Beechcraft King Air F90 |
| PT6A-41/42 / 42A | 850 | Piper PA-42, Beechcraft King Air B200 |
| PT6A-66B | 850 | Piaggio P.180 Avanti II |
| PT6A-140 | 867 | Cessna grand caravan ex |
| PT6A-62 | 950 | Pilatus PC-9 |
| PT6A-65B | 1100 | Beechcraft 1900D , PZL M28 |
| PT6A-67B / D | 1200 | Pilatus PC-12 , Beechcraft 1900D |
| PT6A-68 | 1250 | Beechcraft T-6 Texan II |
| PT6A-67R | 1424 | Shorts 360 |
| PT6A-68B / C | 1600 | Pilatus PC-21 , Embraer EMB 314 Super Tucano |
| PT6B / C series | ||
| PT6B | 981 | AgustaWestland A.119, Sikorsky S-76B |
| PT6C-67C | 1700 | AgustaWestland AW139 |
See also
- TVD-10
- TVD-20
Notes
- β PWC PT6A turboprop engine . www.airwar.ru. Date of appeal September 19, 2019.
- β http://www.ato.ru/content/pratt-whitney-canada-sozdala-prilozhenie-dlya-ekspluatantov-dvigateley-pt6
- β Foreign aircraft and rocket engines. - M.: TsIAM them. P.I. Baranova, 1961. - p. 375
- β Foreign aircraft and rocket engines. - M.: TsIAM them. P.I. Baranova, 1967 .-- p.267