How do you illuminate the Air Stairs?

The correct approach to illuminating the air stairs is by depressing the BRT button. This button is specifically designed to control the brightness of the boarding and deplaning lights, which include those that light the air stairs. When activated, the BRT button enhances visibility, allowing passengers and crew to safely navigate the stairs during boarding and deplaning—especially in low-light conditions.

Using the main lights switch would not specifically target the air stairs, as it controls general cabin lighting rather than focusing it on the boarding area. The emergency lighting system serves a different purpose, providing illumination during power failures or emergencies rather than routine boarding procedures. Pressing the boarding lights button is also effective for illuminating the boarding area, but it is not the designated method for heightening the air stairs light levels specifically. Therefore, choosing the BRT button directly fulfills the requirement for ensuring passenger safety at the air stairs.