section 12 engine starting and ignition

© International Aero Engines Inc 2000

Engine Starting and Ignition Engine Starting and Ignition

System comprises:

Pneumatic Starter Motor. Starter Air Control Valve. Dual Ignition System. Pneumatic Ducting. Start Control Panel on Flight Deck.



Start Panel provides the following functions:

Automatic starting. Manual Starting. Dry Cranking. Wet Cranking. Continuous Ignition.


Pneumatic supplies for the starter can be

provided by:

Auxiliary Power Unit (APU). Ground Supply. The Other Engine (if already started).

Engine Starting and IgnitionEngine Starting and Ignition


During Auto Start, the critical parameters are

monitored by the EEC to identify a faulty start:

Identified as: ‘Hot’ Start. ‘Hung’ Start. No ‘light up’. Pressure Raising and Shut-Off Valve failure. No N1 Rotation



The EEC will carry out an automatic engine shut down (start abort)

Provide a motoring cycle to clear fuel vapours and to cool the engine,



EEC FLIGHT DECK FUEL METERING

UNIT

PR & SOV

COMBUSTION CHAMBER

HIGH PRESSURE COMPRESSOR

EXTERNAL GEARBOX

AIR STARTER

START AIR VALVE

RELAY BOX

HEIU

No. 1

HEIU

No. 2

115V AC IGN No 1 & STANDBY

115V AC IGN No 2

COMBUSTION CHAMBER




Starter Air Duct: All ducting in the system is designed for high

pressure and high temperature operation. ‘Gimbal’ joints are incorporated to permit

working movement. ‘E’-type seals are used on all mating flanges. All mating flanges are secured by ‘V’ band

coupling clamps.


Starter Motor:

Mounted on the forward face of the external gearbox.

Provides the drive to rotate the H.P. compressor to a speed at which engine ‘light-up’ can occur.

The starter motor gears and bearings are lubricated by an integral lubrication system.




Starter Motor: Attached to the external gearbox by quick

attach/detach adapter ring. A quick detach ‘V’ clamp fixes the starter to the ring Servicing features include:

Oil filler/level plug

Drain plug and magnetic chip detector

Oil level sight glass

Oil filler/level plug.

Built in drain plug and magnetic chip detector.

Oil level sight glass


Starter Installation Coupling

Starter AdapterEngine Starter

Gearbox



Starter Air Control Valve: Pneumatically operated, electrically controlled.

Location: Lower right hand side of the Fan Case. ‘Butterfly’ type valve housed in a cylindrical valve

body, with:

In-line flanged end connectors.

An Actuator.

Solenoid valve.

Pressure controller.


Starter Air Control Valve:

Manual Operation: The valve can be manually opened by using a

0.375 inch square drive. Access panel in the right hand fan cowl. Valve position indicator on the valve body. Feedback to the EEC of valve position from a

microswitch.





Valve Opening: Solenoid valve opens when engine start signal

received. Simultaneously closes vent port. Starter delivery pressure causes actuator piston

to move. As piston is mechanically connected to the

starter valve, the starter air valve opens.



Valve closing: When the engine speed reaches approximately

6000 rpm (43%) N2, the solenoid valve de-energises.

Ball valve closes and the air pressure acting on the piston is vented to atmosphere.

Air pressure and spring pressure acting on the smaller piston, cause it to return to the closed position this closes the butterfly valve.



Starter Air Valve - Schematic

TO PNEUMATIC STARTER INLETFlow

Test port

Closed position switch

(Contacts ‘open’ when valve is ‘closed’)

Ambient PressureFilter

Restrictor

Actuator

Ambient Pressure




FlowTO PNEUMATIC STARTER INLET

Test port




Restrictor

Actuator

Ambient Pressure



FlowTO PNEUMATIC STARTER INLET Flow

Ambient Pressure

Restrictor



Actuator

Filter Ambient Pressure

Test port



TO PNEUMATIC STARTER INLETFlow

Test port




Restrictor

Actuator

Ambient Pressure


Ignition:

System comprises of the following:

2 ignition exciter units. 2 igniter plugs - located in the combustion

chamber adjacent to # 7 and # 8 fuel spray nozzles.

2 ‘air cooled’ (H.T.) ignition connector leads.



Ignition:

Dual ignition is automatically selected for:

All in-flight starts. Manual start attempts. Continuous ignition.



Ignition:

Continuous ignition automatically selected if: The engine anti-ice system is ‘on’. Aircraft flaps are extended for: Take-off. Approach. Landing. Continuous ignition may also be selected

manually.



Ignition Test:

the operation of the ignition system can be checked on the ground, with the engine static. Using the maintenance mode of the Centralised Fault Display System (CFDS)



Ignition Relay Box:

Ignition system uses 115V AC supplied by the ‘Normal’ and ‘Essential’ bus bars to the Relay Box.

Controlled by signals from the EEC. Relay Box includes the relay that controls the

115V AC supplies for the P2/T2 probe heating elements.


section 12 engine starting and ignition

Education

automatic starting

manual starting

ignition starter motor

ignition starter air

automatic engine

engine light

pneumatic starter motor

starter motor gears