737 MAX Flight Crew Operations Manual
Engines, APU -
Engine System Description
7.20.2
MN-FLT-OH-201
• in flight when an engine N2 RPM is below idle
• a secondary engine parameter is exceeded.
When the secondary engine indications are automatically displayed, they cannot
be cleared until the condition is no longer present.
Normal Display Format
N1, EGT, and N2 are displayed as both digital readouts and round dial/moving
pointer indications. The digital readouts display numerical values while the
moving pointers indicate relative value.
Oil pressure, oil temperature, and engine vibration indications are both digital
readouts and vertical indication/moving pointers. Fuel flow and oil quantity are
digital readouts only. All digital readouts are enclosed by boxes.
The dials and vertical indications display the normal operating range, caution
range, and operating limits.
Normal operating range is displayed on a dial or vertical indication in white.
N1, EGT, and N2 have operating limits indicated by redlines. EGT also displays
an amber caution limit. If one of these indications exceeds the red or amber line,
the digital readout, box, pointer, and indicator change color to red or amber.
The oil temperature and oil pressure vertical indications have a caution range and
an operating limit redline. If the oil temperature or pressure reaches the caution
range, the digital readout, digital readout box, and pointer all change color to
amber. If one of these indications reach the operating limit, the digital readout,
digital readout box, and pointer all change color to red.
The EEC must receive electrical power to supply engine operating data to the
flight deck engine indications. When the EEC is not powered, N1, N2 and oil
quantity are displayed directly from the engine sensors. Positioning the engine
start switch to GRD supplies electrical power to the EEC and displays
pointers/digits for all engine parameters.
An engine failure alert indication (ENG FAIL) is displayed in amber on the EGT
indicator when the respective engine is operating at a condition below sustainable
idle (63% N2) and the engine start lever is in the IDLE position. The alert remains
until the engine recovers, the engine start lever is moved to CUTOFF, or the
engine fire switch is pulled.
March 1, 2021