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• [ejet:engine_start_system]

Engine Start System

System comprised of:

• ATS
• SCV
• part of the bleed air system
• starting control panel

Control

Start sequence

• START position on control panel
• pressurised air is directed to the ATS, which rotates the engine rotor via the AGB
• FADEC commands ignition and fuel flow on
• FADEC schedules fuel flow to accelerate engine to idle
• FADEC deenergizes the SCV at 50% N2
• FADEC turns off ignition when the engine reaches idle

Note that the isolation valve is automatically controlled only if the XBLEED switch is in the auto position.

Assisted start sequence

• ignition switch AUTO
• bleed air configured to provide air to the SCV
• start/stop selector START (signals MAU to send start switch signal to the FADEC)
• SCV opens
• FADEC commands ignition on at 7% N2
• FADEC command FMU to open at 20% N2
• FADEC deenergizes the SCV at 50% N2
• FADEC turns off ignition when the engine reaches idle

Inflight assisted start is the same except the FADEC opens the metering valve if N2 is not 15% within 15s.

Windmill start sequence

• ignition switch AUTO
• start/stop selector START (signals MAU to send start switch signal to the FADEC)
• start/stop selector START (signals MAU to send start switch signal to the FADEC)
• SCV does not open since there is no air from the bleed system available
• FADEC senses the SCV is still closed and commands ignition at 7% N2 and fuel flow at 7.2% N2 or after 15s
• FADEC turns off ignition when the engine reaches idle

See also

Engines

Start Protection

Categories: Embraer 170/190 | Engine