737 MAX Flight Crew Operations Manual
Warning Systems -
System Description
MN-FLT-OH-201
15.20.19
In-Air Overrun Warning
1B785, 1B786, 1B814 - 1J594
(as installed)
The In-Air Overrun Warning alerts the flight crew that an overrun is likely to
occur if the approach and landing is continued, based upon the airplane's energy
state, the pilot-entered runway condition, and the remaining available landing
distance. The alert is armed from 500 feet above the runway touchdown zone
elevation (TDZE) until airplane touchdown.
The alert consists of a GO AROUND visual alert shown on the Primary Flight
Display (PFD), and an "OVERRUN, GO AROUND" aural alert. The aural alert
will repeat under the following conditions:
• Height above the TDZE is 150 feet or less, and
• the alert condition has been true for at least seven seconds.
The Enhanced Ground Proximity Warning System (EGPWS) continually
computes a predicted landing distance. The in-air overrun alert activates when the
predicted landing distance exceeds the distance to the end of the runway. The
distance to the end of the runway is based on the EGPWS runway database and
the airplane’s position.
The in-air overrun alert is inhibited when any of the following conditions are true:
• Height above TDZE is greater than 500 feet;
• the air/ground signal indicates the airplane is on the ground;
• at altitudes greater than 50 feet above TDZE, the descent rate decreases
to less than 300 feet per minute for at least two seconds (the airplane is
no longer descending on the approach);
• a landing runway has not been identified by the EGPWS;
• the airplane’s position accuracy is insufficient;
• the Runway Inhibit switch on the GPWS control panel is in the
INHIBIT position;
• left or right thrust lever is set to at least go-around thrust (a go-around
has been initiated);
• left or right thrust lever is set to idle position, and left or right reverse
thrust lever is approaching the reverse idle detent (the thrust reversers
are about to be deployed);
• the flaps are not set to 15, 30 or 40 degrees (flaps are not set for
landing);
• the radio altitude is less than 0 feet.
October 26, 2021
