The exterior lights provide illumination for aircraft identification, direction, and to aid in the safe operation of the airplane. These are the exterior lights on a Boeing 737 aircraft:
- Wing illumination
- Landing lights
- Taxi and runway turnoff lights
- White, red, and green position lights
- White anti-collision lights
- Red anti-collision lights
- Logo lights
- Emergency lights
Wing Illumination Lights
Lights on each side of the airplane illuminate the leading edge of each wing. These lights also provide additional lighting for ground servicing of the airplane. A switch on the forward overhead panel (P5) in the flight compartment controls these lights.
Landing and Ground Maneuvering Lights
The landing, taxi, and runway turnoff light (LTRTL) assembly is located inside the left and right wing strakelets and uses light-emitting diodes (LEDs) as the light source. The LTRTL assembly consists of a power supply, inboard and outboard main LED arrays, and a runway turnoff light LED array. The power supply is mounted in the cavity of the wing strakelet behind the LED arrays. Refer to the figure below.
The inboard and outboard main LED arrays provide lighting for landing and takeoff operations at a maximum power setting. A left lighting control switch and a right lighting control switch on the forward overhead panel (P5) in the flight compartment control this function. The inboard and outboard main LED arrays provide lighting for taxi operations at a lower power setting. The taxi light function is controlled by a single switch on the forward overhead panel (P5). The landing light function overrides the taxi light function when the landing light and taxi light switches are in the “ON” position.
The runway turnoff light function is provided by the runway turnoff LED array, located inboard of the main LED arrays. The runway turnoff lights illuminate runway edges and turnoffs. The left and right runway turnoff LED arrays are controlled by separate switches on the forward overhead panel (P5).
Position Lights
Each winglet is equipped with one LED position light and one LED marker light. The forward position light on the left winglet is red, while the forward position light on the right winglet is green. The aft marker lights are white and assist service personnel during ground operations.
There is also one white LED position light on each side of the tailcone. A switch on the forward overhead panel (P5) in the flight compartment controls these lights.
Anti-Collision Lights
There are red LED anti-collision strobe lights located as follows:
- One on the top of the fuselage
- One on the bottom of the fuselage
The light on the top of the fuselage can be replaced from inside the airplane.
There are 4 high-intensity white LED anti-collision strobe lights located as follows:
- One on the left winglet
- One on the right winglet
- One on each side of the tailcone
The lights on the tailcone are colocated with the position lights.
A switch on the forward overhead panel (P5) in the flight compartment controls these lights.
Logo Lights
Lights in the horizontal stabilizer illuminate the operator’s emblem on both sides of the vertical stabilizer. A switch on the forward overhead panel (P5) in the flight compartment controls these lights.
Winglet Aft Marker Lights
Winglet aft marker lights illuminate the lower portion of the winglet.
Exterior Emergency Lights
An exterior emergency light is located aft of each entry and service door on the left and right sides of the airplane and illuminates the escape slide when the slide is deployed. Overwing emergency lights are positioned to illuminate the escape path area on the wings. Offwing ground illumination lights are located aft of each wing.
All emergency lights are powered by separate DC sources (battery packs).
