Turbomeca Astazou


The Turbomeca Astazou is a highly successful series of turboprop and turboshaft engines, first run in 1957. The original version weighed and developed at 40,000 rpm. It was admitted for aviation service on May 29, 1961, after a 150-hour test run. The main developing engineer was G. Sporer. It was named after two summits of the Pyrenees.
A simplified version was built by Agusta as the Turbomeca-Agusta TA.230.

Design and development

The Astazou IIA version was derived from the original Astazou powerplant for use in helicopters. By 1993, 2,200 had been built. As of 2007, it was still in production. However, many aircraft initially equipped with it, especially the heavier ones, have since been upgraded with more powerful engines.
The basic design of the single shaft Astazou has a two-stage compressor, with the first stage an axial and the second stage a radial design. It has an annular combustion chamber, after which the hot exhaust enters a three-stage axial turbine. Maximum rpm was later raised to 43,500.
Production turbines have a reduction gear in front of the air inlet, reducing propeller speed to 1,800, 2,080, 2,200, 0r 2,400 rpm, or 6,000 rpm in the helicopter version. The engine controls itself automatically, so the pilot only needs to set the desired rpms.
, with twin Astazou XIV, showing the distinctive annular air inlet and long reduction gear housing
As of the Astazou X, the engine received a second axial compressor stage. This was the engine for the Potez 840. The Astazou XIV and XVI were also marketed by Rolls-Royce Turboméca International Ltd under the names AZ14 and AZ16, respectively.
Power was steadily increased over the years, with the Eurocopter Dauphin's dual Astazou XVIII developing 783 kW each. The Astazou XX received a third axial stage, raising compression even further to achieve a projected output of in the turboprop application. The XXB derivative, used in the single engine Aérospatiale SA 361H Dauphin, delivered.

Astazou XVI

The circular air inlet behind the reduction gear has a de-icing device using hot air. The compressor's two axial stages use blisks. The shaft runs on ball bearings. Air flow through the annular combustion chamber is S-wise, with fuel being added in radial direction by a rotating atomizer disc. The blades of the three-stage turbine's wheels, also blisks, are air-cooled from the inside. The jet nozzle is fixed with an interior cone. Auxiliary drives are mounted on a mounting plate behind the inlet, which also has the connections for starter motor/generator, oil and fuel pumps, engine speed control and tachometer. There are also optional drives for an AC generator and a hydraulic pump. The whole engine is mounted at three points, two trunnions on the right and left front of the turbine casing and one on its underside to the rear. Speed control is effected automatically by governing the injection volume, with a thermal regulator allowing for short-term overloads.

Variants

;Astazou I:
;Astazou II:Single-stage axial plus single-stage centrifugal compressor, annular combustor, three-stage turbine
;Astazou IIA:
;Astazou III:
;Astazou IIIA:
;Astazou IIIC:
;Astazou IIIC2:
;Astazou IIIN:
;Astazou IIIN2:
;Astazou VI:Coupled Astazou
;Astazou X:The X and subsequent engines had a second axial compressor stage added.
;Astazou XII:
;Astazou XIV:Two-stage axial plus single-stage centrifugal compressor, annular combustor, three-stage turbine. Integral front mounted
gearbox.
;Astazou XIVA:
;Astazou XIVB:
;Astazou XIVD:
;Astazou XIVC:
;Astazou XIVH:
;Astazou XIVM:
;Astazou XVI:
;Astazou XVIII:
;Astazou XVIIIA:
;Astazou XX:A third axial compressor stage added for increased pressure ratio.
;Astazou XXB:
;Turbomeca-Agusta TA.230:A simplified version built by Agusta.
;Rolls-Royce Turboméca AZ14: The Astazou XIV marketed by Rolls-Royce Turboméca International Ltd as the AZ14
;Rolls-Royce Turboméca AZ16: The Astazou XVI marketed by Rolls-Royce Turboméca International Ltd as the AZ16

Applications

Fixed-wing aircraft

ParameterIIIIAIIIC2/N2XXIVB/FXIVHXIVMXVI
Max output
Length
Diameter
Width
Height
Weight
Air mass flow/sec
Pressure ratio6:17.5:18:18:18:18.15:1