737 MAX Flight Crew Operations Manual
Supplementary Procedures -
Adverse Weather
SP.16.4
MN-FLT-OH-201
Engine Start Procedure
Do the normal Engine Start Procedure with the following modifications:
• If the engine has been cold soaked for one or more hours at ambient
temperatures below -40°C, do not start or motor the engine.
Maintenance personnel should do appropriate procedures for adverse
weather heating of the Hydro-Mechanical Unit.
• If the engine has been cold soaked for three or more hours at ambient
temperatures below -40°C, do not start or motor the engine.
Maintenance personnel should do appropriate procedures for adverse
weather starter servicing.
• If ambient temperature is below -35°C, idle the engine for two
minutes before changing thrust lever position.
• Several minutes may be needed for oil pressure to reach the normal
operating pressure. During this period, oil pressure may go above the
normal range and the OIL FILTER BYPASS light may illuminate.
Operate the engine at idle thrust until oil pressure returns to the
normal range.
• If the oil pressure remains above the normal range after the oil
temperature has stabilized within limits, shut down the engine.
• Display units may require additional warm-up time before displayed
engine indications accurately show changing values. Display units
may appear less bright than normal.
Engine Anti-ice Operation - On the Ground
Engine anti-ice must be selected ON immediately after both engines are
started and remain on during all ground operations when icing conditions
exist or are anticipated.
WARNING: Do not rely on airframe visual icing cues before
activating engine anti-ice. Use the temperature and
visible moisture criteria because late activation of
engine anti-ice may allow excessive ingestion of ice
and result in engine damage or failure.
CAUTION: Do not use engine anti-ice when OAT is above 10°C.
When engine anti-ice is needed:
YA201 - YD256, YF631 - YV671
ENGINE START switches .............................. CONT
F/O
ENGINE ANTI-ICE switches.............................. ON
F/O
Verify that the COWL VALVE OPEN lights illuminate
bright, then dim.
Verify that the COWL ANTI-ICE lights are extinguished.
March 1, 2021
