Lighting

Question 0

How many power sources are available for emergency evacuation lighting?

Answer 0

Two:

The DC emergency bus via a voltage divider
6 V batteries which are charged from the DC emergency bus

Note: they have a 10 minute capacity

Question 1

With no power available to the aircraft how can we obtain some lighting in the cabin?

Answer 1

A switch located by the entrance door provides for two minutes of cockpit lighting and emergency exit lighting.

Note: main cabin door must be open

Question 2

With DC emergency bus only, what cockpit lighting is available?

Answer 2

The right-hand dome light
LH three lights located below the glareshield
The overhead pedestal light
The compass light

Question 3

What does the minimum cabin lighting switch do?

Answer 3

It enables us to control the min cabin lights powered by the main battery.

On the right-hand side of the cabin every other light is illuminated.

The switch doesn’t do anything unless you’re on battery power only

Question 4

When would the emergency exit lights illuminate?

Answer 4

Switch is:
ON–they are on
ARM–lights illuminate if DC emergency bus voltage drops below 18 V or if both generators are lost. The lights extinguish if DC emergency bus voltage is over 20 volts and at least one generator is operating.
DISARM–exit light system is deactivated

Note: the flight attendants emergency light switch will override the ARM and DISARM positions

Question 5

What are the two sources of power for the emergency lights?

Answer 5

6V 10 min batteries

Emergency batt bus