Emergency Exit Doors
B737-700
Two Type III emergency exits are located in the passenger cabin over the wings. These are
canopy-type doors and are held in place by mechanical locks and airplane cabin pressure.
B737-800/900
Four Type III emergency exits are located in the passenger cabin over the wings.
These are canopy-type doors and are held in place by mechanical locks and
airplane cabin pressure.
The doors can be opened from inside or outside of the airplane by a spring–loaded handle
at the top of the door. The 28 Volt DC flight lock system is designed to ensure that the flight
lock will automatically lock during takeoff, in-flight, and landing and unlock on the ground to
allow for opening of the door in emergency situations. Commands for the flight lock to lock
and unlock are dependent upon engine speed, thrust lever position, air/ground mode
status and the open/closed status of the doors.
The overwing emergency exits lock when:
- Three of the four Entry/Service doors are closed and
- either engine is running and
- the airplane air/ground logic indicates that the airplane is in the air or both thrust
levers are advanced.
The overwing emergency exits unlock when any one of the above conditions is not
met or DC power is lost.
The LEFT OVERWING and/or RIGHT OVERWING warning lights, DOORS annunciator and
MASTER CAUTION light illuminate when an emergency exit door is not fully closed and
locked or when the flight lock is not engaged, either during the takeoff roll or in-flight.
