Air intake and fan

Annular air entry containing one row of variable-incidence entry vanes, a single stage compressor fan and one row of fixed straightening vanes.

Fan is driven by compressor shaft through coupling and reduction gear. After fan the air is divided into primary and secondary flows, the former passing to the power section and the latter by-passing that section in an annular casing to the tailpipe where it mixes with the primary jet efflux.

Compressor

Single-stage centrifugal compressor. Single-sided impeller.

Combustion chamber

Annular type, with rotary fuel injection as in Piméné.

Turbine

Two-stage axial flow turbine

Jet Pipe

Fixed inner cone, annular turbine nozzle and outer pipe wherein the jet efflux and by passed secondary air mix.

Control

Single throttle lever determine the fuel flow and position of variable incidence vanes. Egine speed controled by centrifugal governor. For rapid manoeuvrability a push button operates and electro-hydraulic servo-motor with over-rides manual control and at maximum rotation speed the throttle lever can be used solely to control the entry vanes to obtain rapid variation of thrust without having to oercome the inertia of the rotating assembly.

Starting

Throttle at "starter" setting only controls fuel delivery. Entry vanes are closed and engine speed governor is ineffective. Normal starter spins rotating assembly. When engine reaches a rotating speed of 70 per cent. of maximum governor and vane become operative.