GE4/J5P
Type: Single-shaft axial turbojet with afterburner.
Intake: Annular, comprising front structural frame with eight radial struts supporting compressor front bearing housing.
Compressor: Nine-stage axial single-shaft unit with variable incidence inlet guide vanes and stator vanes, giving large stall margin for inlet distortion tolerance. Front and rear groups of stators are individually actuated for starting airflow control and for high airflow capability at supersonic speeds. Rotor construction is combined drum-and-disc with thin-section centreless discs. No 1 disc is overhung on forward conical extension shaft supported by compressor front roller bearing. Rearward conical extension shaft attached to periphery of No 9 disc is supported by centre main ball thrust bearing. Thin-section air tube located on front and rear conical shafts, passes through disc centres. Compressor delivery diffuser is integral with mid-section structural frame supporting centre main bearing. All stator vanes carried on inner and outer swivel bearings, with inner support rings sealing against rotor inter-disc drums. For reduced weight, rotor blades in stages 1 to 4 are hollow diffusion-bonded titanium alloy, and stage 5 to 9 electro-chemically drilled superalloy. Pressure ratio 12-5:1, mass flow 633 lb/sec (287 kg/sec).
Combustor: Fully annular design of moderately high heat release rate with primary air annulus having multiple axial swirl cups.
Turbine: Two-stage axial unit with air-cooled cast alloy nozzle guide vanes and rotor blades. Thin-section centreless discs with arched inter-stage spacers. Rotor blades have dovetail root fittings and second stage blades are tip-shrouded. Forward conical extension shaft attached to periphery of stage 1 disc locates with compressor rear conical shaft at centre main ball thrust bearing. Rearward tubular shaft extension from stage 2 disc located in rear main roller bearing. Stage 2 nozzle guide vanes cantilever mounted from outer end, with seal onto interdisc spacer at inner end.
Exhaust System: Annular exhaust duct from turbine with rear structural frame, with radial/tangential struts, supporting curved centre cone and turbine rear bearing. Turbine entry temperature at T-O, in excess of 2,000°F (1,366°K).
Afterburner: Conventional system with four V-gutter flame stabilisers mounted on radial struts in exhaust duct. Two-stage fuel injection enables thrust modulation over full augmentor temperature range. Annular thermal shield protects duct wall between combustion zone and variable nozzle. Fuel supply manifold encased in external annulus around exhaust duct.
Exhaust Nozzle and Thrust Reverser: Two-stage nozzle with integral thrust reverser. Comprises variable area primary nozzle positioned by hydraulic actuators which also "overtravel" to act as reverser blocker. Long-section secondary shroud includes tertiary air inlet doors which open for low speed operation and can be selectively locked open for reverser operation. Secondary nozzle provides guided expansion of exhaust gases and is pressure-positioned for optimum area ratio. For reverse thrust, primary nozzle translates rearwards to expose thrust reverser ducts (tertiary air inlet doors), closing to form a block, thus directing gases forward through the ducts. Provision also for noise suppression.
Fuel Systems: Hydromechanical primary engine and afterburner fuel control systems.
Accessories: All engine controls and accessories housed in sealed compartment under front of engine cooled by normal circulation of fuel to protect from high temperature environment at supersonic cruise. Accessory drive is via bevel gear box in nose cone, driven-ofF front of compressor. Drive shafts for accessories and airframe purposes pass through front frame radial struts.
Dimensions:
Max diameter (over exhaust nozzle) 89.5 in (2,280 mm)
Length overall 308 in (7,823 mm)
Weight, dry: (Dependent on specific installational features) 11,300 lb (5,100 kg)
Performance Ratings: Max augmented T-O
67,000 lb (30, 390kg) st at 5,200 rpm Max augmented T-O
50,500 lb (22,900 kg) st at 5,200 rpm Max flight conditions
Mach 2.7 at 82,000 ft (24,994 m)
Cruise at Mach 2.7 and 65,000 ft (19,812 m) 15,000 lb (6,804 kg)
Specific Fuel Consumption:
At cruise rating 1.50 lb/lb/hr (1.50 kg/kg/hr)