The Turbomeca Astazou XIV Powerplant: A description of the Astazou turboprop engine used in the Jetstream and its operation Available to Purchase

THE Sociéte Turbomeca Astazou, shown in the cutaway drawing, fig. 2, is a fixed shaft engine, running at the constant speed of 43,000 r.p.m. It has a three‐stage compressor, two axial stages followed by a centrifugal stage, after which there is the annular combustion chamber and finally the three‐stage turbine. The reduction gear, a two‐stage step‐down spur gear with three layshafts (or ‘stationary planets’), delivers 1,783 r.p.m. at the propeller shaft. Fuel flows along the main shaft from the front and enters the combustion chamber via a slinger ring, thus giving adequate vapourisation without the need for unduly small injection nozzles.