Abnormal Start Protection (Ground Starts Only)
During ground starts, the EEC monitors engine parameters to detect impending hot starts,
EGT start limit exceedances, and wet starts. These protection features do not function
during inflight starts.
If an impending hot start is detected by a rapid rise in EGT or EGT approaching the start
limit, the white box surrounding the EGT digital readout flashes. The flashing white box
resets when the start lever is moved to CUTOFF or the engine reaches idle N2.
If the EGT exceeds the starting limit, the EGT display, both box and dial, turn red. The EEC
automatically turns off the ignition and shuts off fuel to the engine. The alert terminates and
the display returns to white when EGT drops below the start limit. Following shutdown of
both engines, the EGT box turns red to remind the crew of the exceedance.
A wet start occurs if the EGT does not rise after the start lever is moved to IDLE. If a wet
start is detected, the EEC turns off the ignition and shuts off fuel to the engine 15 seconds
after the start lever is moved to IDLE.
Engine Ignition System
Each engine has two igniter plugs. The EEC arms the igniter plug(s) selected by the ignition
select switch. The left igniter plug receives power from the associated AC transfer bus. The
right igniter plug receives power from the AC standby bus.
Auto-Relight
An auto-relight capability is provided for flameout protection. Whenever the EEC detects an
engine flameout, both igniters are activated. A flameout is detected when an uncommanded
rapid decrease in N2 occurs, or N2 is below idle RPM.
