Aircraft Exterior Lighting PDF

Aircraft Exterior Lighting Exterior Lighting Systems Exterior lights on an aeroplane The requirements for aircraft external lights intended to reduce the possibility of mid-air collisions are laid out in annex 8 of the International Civil Aviation Organisation (ICAO) Chicago Convention. The image sh...

Aircraft Exterior Lighting Exterior Lighting Systems Exterior lights on an aeroplane The requirements for aircraft external lights intended to reduce the possibility of mid-air collisions are laid out in annex 8 of the International Civil Aviation Organisation (ICAO) Chicago Convention. The image shows most of the exterior lighting used on a civil aircraft. The main exterior lighting systems to be identified includes the following: Navigation lights Anti-collision lights Landing and taxi lights Wing leading edge (Ice detection) lights Strobe lights. 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 114 of 140 Navigation Lights Navigation lights, also called position lights, are located on each wing tip and at the tail of an aircraft. Navigation lights are coloured so that aircraft flying in same vicinity can determine which direction the other aircraft travelling. Tail lights are white and located on the tail. They may also be located behind the wingtip coloured lights. The left-hand side (port) navigation light is coloured red. The right-hand side (starboard) navigation light is coloured green. Navigation lights must be visible from certain angles Large commercial aircraft have a redundancy system, with two bulbs placed in parallel and illuminated simultaneously; this system is also known as multi-bulb navigation lights. If one bulb fails, illumination will be provided by the other bulb until the aircraft arrives at a maintenance facility. 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 115 of 140 Multi-bulb navigation light circuit schematic Caution for handling bulbs Note: In a multi-bulb wingtip and tail setup, the following minimum must be operative before dispatch for night operations: One stationary red wingtip bulb One stationary green wingtip bulb One stationary white taillight at each wingtip position. 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 116 of 140 Anti-Collision Beacons An anti-collision light, also called a rotating beacon, is a flashing red beacon producing between 40 and 100 flashes per minute. They should be visible from all directions within an angle of 30 degrees above and below the horizontal plane of the aircraft. An aircraft can have one unit on top of the vertical stabiliser or one on top of the fuselage and one on the underside of the fuselage. Anti-collision light There are three types of anti-collision beacons: Rotary reflector type Rotating bulb type Red strobe type. Rotary Reflector Type Light aircraft use a rotating reflector type which has a small motor and gear train driving a reflector around a stationary bulb. The light has a red lens. Larger aircraft use a sealed beam shining onto a double reflector rotated by a small motor and gear train above the sealed beam. 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 117 of 140 Rotating Bulb Type The rotating-bulb-type anti-collision light has two bulbs rotated by a small electric motor and gear train inside a red lens. The reflective surface on the bulb covers approximately half the bulb surface and is positioned with the reflective surfaces back to back. Reflector bulb Red Strobe Type An anti-collision red strobe light looks similar externally to other type of anti-collision lights but utilises a high-intensity strobe light tube under a red lens, instead of incandescent bulbs. The highintensity flash is generated from a strobe unit located independently of the strobe light. This power source supplies high voltage to the strobe unit at the required flash rate. 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 118 of 140 White Collision-Avoidance Strobe Lights A white collision-avoidance strobe light is mounted on each wingtip. Some larger aircraft have a third light mounted on the tail. The strobe lights give an extremely intense flash of white light for a very short period at a frequency of 50 to 80 times a minute. The flash should be visual from any point around the aircraft in an area 30 degrees above and below the aircraft horizon. They denote that the aircraft is in flight. Due to their intensity, they are switched on just before takeoff and switched off after exiting the runway on landing. Strobe Light Flash Tube Strobe light circuit A strobe light xenon flash tube is filled with gas and has a cathode, anode and an external trigger electrode. The clear tube can be made from glass or quartz. Glass tubes should not be touched by hand, so care should be taken when changing the tube. If the tube is touched, it should be cleaned with a soft, dry cloth. Power packs can be manufactured to supply one, two or three lights. If a multi-light installation is installed with single power packs, the packs have to be interconnected so the lights are synchronised to flash at the same time. Power packs are located independent of the strobe unit, usually in a water proof section of the aircraft. 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 119 of 140 Handling Precautions The output power from the power pack can be lethal. Always ensure that input power to the power pack is disconnected for five minutes before any maintenance is performed, unless otherwise stated in manual. The white flashes produced by a strobe light can cause eye damage if looked at from a close position. Do not look directly at an operating strobe. Do not operate strobes during refuelling operations. Do not touch the tube assembly with bare hands. CASA has reported on-the-ground explosions and a fatal crash involving strobe lights mounted on wingtip fuel tanks. It is suspected that because of the high voltage, bad connections (including the airframe return path) can cause arcs to occur and ignite fuel vapour, leading to an explosion or fire. Care must be taken to ensure that connections are clean and secure and that there is return path bonding so arcing to the structure will not occur. Care must also be taken to ensure there are no fuel leaks or vapour sources in the strobe light area. Landing Lights Landing lights are normally cooled by the airflow during flight; therefore, care should be taken not to overheat them on the ground. These lights generate a lot of heat so testing on ground should be carried out quickly. Caution for landing light operation The type of bulb used in landing lights can be a pre-focused bulb placed in a parabolic reflector or a sealed beam. Most aircraft use sealed beams. When replacing lamps, tighten the retaining fixtures evenly so the glass sealed beam will not be stressed, which may cause it to crack. A crack in a sealed beam allows air to enter the bulb, and the filament will burn out. Some landing lights extend to one position only; with this type, the landing light is switch is set to on, and the landing light extends to a pre-set position where a cam depresses a micro-switch and stops the actuator motor. 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 120 of 140 Another type extension system can extend the landing light to two or more pre-set positions. This system has more than one position on the landing light switch, for example, approach and landing. For each selected switch position, there is a micro-switch which the cam will strike, stopping the light in that position. Some aircraft use these types of landing lights as taxi lights, and on selection of taxi, the lamp is stopped in a position suitable for taxiing. This system is also used when the landing light is installed in a flap fairing. At each of the flap settings, a micro switch and cam are used to extend or retract the landing light to ensure that it remains parallel with the aircraft’s flightpath. This occurs automatically when the landing light switch is selected on and the flaps are cycled through their range. Some aircraft have a landing light manual selection; the light is operated by a spring-loaded centre off position switch marked “extend-off-retract.” This system allows the crew to stop the light at any angle. Micro-switches limit full extension and retraction to prevent damage to the motor and gear train. Schematic for retractable landing light 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 121 of 140 Quartz Halogen Bulbs Quartz halogen bulbs are used in some aircraft taxi lights, landing lights and floodlights. Their envelopes are made of quartz, which withstands much higher temperatures than glass. The hotter filament temperature produces more light for the same electrical power, and these bulbs have a longer life than the ordinary incandescent bulb. Care must be taken not to touch the envelope of this type of bulb. If it is handled it must be cleaned with lead-free spirit. Landing lights may be fixed or retractable. Fixed landing lights can be set in the nose or leading edge of the wing behind a streamlined plastic cover. Their beam is fixed and can only be adjusted by removing the cover and adjusting the beam guiding screws. Retractable landing lights are mounted under the wing, in flaps or under the fuselage. When retracted, they will be flush with the surface of the aircraft. They can be extended out to one or more positions and are driven by a small split-field rotary actuator and a gear train. Taxi Lights Most taxi lights are fixed; they are typically attached to the nose landing gear. By attaching it to the steering part of nose landing gear of the aircraft, the beam will follow the intended direction of the aircraft. The electrical circuit is the same as for fixed landing lights. Taxi Light Operation Taxi and runway turn-off lights 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 122 of 140 There are three switches on the panel to control the taxi and runway lights. There is one switch for the nose gear taxi light and one switch for each runway turnoff light. Landing, taxi and runway light switches When the runway turnoff switches are in the on position, 28-V AC goes to the lights. When the nose gear taxi light switch is in the on position, 28-V AC from a transformer goes to the light. When the nose gear taxi light switch is in the dim position and the nose gear is down and locked, these things occur: The taxi light contact relay energises. 115-V AC goes across the nose gear taxi light transformer. The transformer sends a signal to the nose gear taxi light. The nose gear taxi light produces a dim light. The bright position is the same, except the 115-V AC goes to the centre tap of the transformer, and the nose gear light produces a bright light. The nose gear taxi light shuts off automatically when the nose gear is not ‘down and locked.’ Caution for taxi light operation 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 123 of 140 Ice Detection or Wing Leading Edge Lights Ice detection, leading edge or wing illumination lights are mounted in the side of the fuselage under a glass or plastic lens; these lights focus a beam along the wing leading edge. This allows the pilot to visually detect ice formation on the wing leading edge. A sealed beam lamp is typically used. On some aircraft, this type of ice detection is used in conjunction with a black patch painted on the wing leading edge. Ice detection and leading-edge lights have a basic on-off switch control. Wing illumination light 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 124 of 140 Internal Lighting Systems Cabin Lighting Cabin lights are used to illuminate the main cabin of the aircraft. They are located in the ceiling or near the overhead lockers. Most modern aircraft have LED or fluorescent lighting which use indirect lighting techniques to disperse the light around the cabin. The controls are located at the flight attendant station of the aircraft. In larger commercial aircraft, several control units may be used to control different sections of the aircraft. Power to the cabin lighting is provided by the ground service bus, as this allows for the operation of the cabin lighting without the need for the aircraft AC power to be fully activated. © Aviation Australia Sample of a cabin lighting circuit 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 125 of 140 Cabin Window Lighting Cabin window lighting is used on most commercial aircraft to improve lighting of the seating area. They are usually fitted in parallel along the side of the interior of the aircraft. Fluorescent tubes and LEDs are commonly used. Fluorescent systems, use a ballast unit instead of a fluorescent starter. They are controlled from the flight attendant station, either at the front or the rear of the aircraft. In some larger aircraft, the window lighting maybe divided into sections controlled from separate locations within the aircraft. The window lighting system is run independently of other cabin lighting in most aircraft. © Aviation Australia Example of a cabin window lighting circuit 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 126 of 140 Passenger Advisory Signs Passenger advisory signs are used to advise the passengers and cabin crew of a safety requirement, such as “fasten seat belts,” “no smoking,” “return to seat” and “toilet occupied-vacant.” The signs are illuminated by electroluminescent lighting or small incandescent globes which are placed behind a transparent cover coated with an opaque covering. The lettering is cut out of the opaque cover, and the light shows the sign. Advisory Sign Operation Except for lavatory occupied signs, advisory signs are controlled by the flight crew with switches on the flight deck and are simple circuits. However, some aircraft also have automatic control of these signs which will illuminate them in certain situations, for example: When the landing gear lever is placed in the down position A flap selection is made If cabin decompression occurs. When any of the signs are illuminated (except the lavatory occupied), an audio tone sounds over the PA system. © Aviation Australia Example advisory sign circuit diagram 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 127 of 140 Lavatory Lighting The lavatory occupied-vacant signs are simply a circuit-breaker, switch and the lights for each of the individual lavatories. The circuit also uses a switch located in the lavatory door latch. When the passenger locks the door, a plunger strikes against the micro switch in the door jamb. This closes the circuit and illuminates the occupied sign and lavatory interior lighting. When the door is unlocked, the micro switch is released and the sign extinguishes. © Aviation Australia Example of a lavatory advisory lighting circuit 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 128 of 140 Passenger Reading Lights Reading lamps provide a restricted light in the reading area of a passenger so as not to annoy other passengers. Some aircraft may have a master switch located on the flight attendant panel. Each light is individually switched, and the circuit is simply powered from a circuit-breaker to individual switches and lights. Some aircraft reading lights are controlled from the passenger seats through electronic modules located under the seats. © Aviation Australia Example of a passenger reading light circuit Flight Compartment Lighting Flight compartment lighting has to be sufficient to illuminate all controls, switches, instruments and panel inscriptions with uniform intensity but not shine at or distract the flight crew in any way. Flood or background lighting in modern civil aircraft is usually white, while some older civil aircraft have red lighting fitted. There are five main types of cockpit lighting: Integral lighting Post or pillar lights Trans-illuminated panels Floodlights Utility or wander lights. 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 129 of 140 Integral Instrument Panel Lighting Integral instrument panel lighting is used to illuminate flight deck instruments. In older aircraft, it was used for most instrumentation illumination. In glass cockpits, it is used for digital display light intensity control and for the standby analogue instrumentation illumination. In two-pilot aircraft, both pilots are able to control their own instrument lighting, independent of the other. The pilot in command will also control the centre instrument panel (usually engine and standby instruments). Integral lighting comes from globes inside the instrument. One form has several smaller globes positioned around the dial in a plastic ring. This diffuses the light on the dial. © Aviation Australia Example of integral instrument panel lighting circuit 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 130 of 140 Post or Pillar Lights Post/pillar lights are used in areas where there is insufficient light from other sources. They are screwed to the instrument panel and have a hood which directs the light down and across a 90 degrees arc. Usually, the hood can be turned through 360 degrees so it can be adjusted to ensure the light illuminates the correct area. © Aviation Australia Pillar and bridge lights Trans-Illuminated Panels Trans-illuminated panels, or indirect lighting, are made from transparent plastic or Perspex which is painted with a translucent white and then an opaque black or grey paint. The opaque material is engraved with inscriptions such as “pilot’s panel lights” around switches and other controls. Light shines through the engraved inscriptions. © Aviation Australia A trans-illuminated panel schematic diagram 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 131 of 140 This method of cockpit lighting is most commonly used to display system controls and switching (e.g., hydraulic panel, electrical panel, etc). It operates through a dimmer unit, controlled by switches in the flight compartment. An advantage of trans-illuminated panels is a minimum number of bulbs can illuminate large areas of paneling. © Aviation Australia Trans-illuminated panel example layout 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 132 of 140 Floodlights Floodlights are used to illuminate large areas, such as side and centre consoles, floors, circuit-breaker panels and main instrument panels. They are usually fluorescent tubes but can be incandescent bulbs with a dimming facility or LEDs. The lights are usually controlled through a switch and a dimmer control unit. © Aviation Australia Flood lighting example schematic and circuit diagram 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 133 of 140 Utility or Wander Lights Wander lights can be used as floodlights, map reading lights and emergency lights to replace a failed light system and are often powered from a hot battery bus so they can be used as emergency lighting in the event of a total power failure. They have a flexible chord and are mounted in a ball clip socket. They can be removed by hand and placed in other ball clip sockets around the cockpit or hand held. They can also be pivoted up and down and left to right. The rheostat controls the switching and intensity of the light. The bezel on some of these lights is used to focus the beam. Some have two lenses: one white and the other red. Wander light 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 134 of 140 Cargo Compartment Lights Cargo compartment lights are fitted in the aircraft’s cargo compartments. They can be fluorescent or incandescent and are simple light systems. Most commercial aircraft cargo lighting systems operate through a micro-switch located in the door of the cargo compartment. When the door is closed, regardless of the light switch being selected on or off, they are extinguished. When the cargo door is opened, the cargo compartment lights are switched on through the normal light located in the cargo door opening. © Aviation Australia Cargo compartment light schematic Loading Lights Loading lights illuminate apron areas where cargo and baggage loading takes place. They are simple light systems. The controls for these lights are usually located on the outside of the aircraft and, in some aircraft, are controlled by a micro-switch in the aircrafts landing gear, which turns on the lights when the weight of the aircraft is placed on the wheels. 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 135 of 140 Emergency Lighting Emergency Lights Emergency lighting must mark all exits and illuminate the cabin with enough light for the crew to operate emergency equipment and guide passengers to safety, without outside lighting. The intensity and position requirements of these lights are detailed in relevant ICAO and civil aviation regulations. © Aviation Australia Emergency lighting 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 136 of 140 Emergency Exit Lights Emergency exit lights are fitted adjacent to all emergency exits. These lights indicate “exit” and have a window at the bottom using white light to illuminate the exit, therefore acting as emergency lighting at the same time. In older aircraft, they were powered from hot battery buses and could be switched manually by the crew or automatically by a crash or inertia switch or when the aircrafts power supplies were deactivated. Modern aircraft usually have an independent nickel cadmium battery pack. If aircraft power fails, the battery is automatically switched to power the emergency light. Under normal operating conditions, the battery is charged from the aircraft DC electrical system. © Aviation Australia Emergency light system schematic The primary control for emergency lighting is a single guarded three-position cockpit emergency exit light switch (in the cockpit) marked “off-armed-on.” An on-off switch is installed on the cabin attendants emergency light panel in the cabin. When parking the aircraft, it is important to ensure the emergency lights switch is switched off and not in the arm position before turning off aircraft electrical power; failure to do so will cause the emergency to illuminate. If left un-noticed, the emergency light battery packs will be exhausted, rendering the aircraft unserviceable. Depending on the type and age, when power is removed from some aircraft before the emergency lights are disarmed, aircraft power must be restored so the emergency light switch can be selected to off to reset the system. Other aircraft do not require aircraft power to be connected for the emergency light switch to be selected to off to reset the system. 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 137 of 140 © Aviation Australia Passenger cabin aisle and exit lights Operational Requirements Emergency cabin lights must be operative for night operations. Individual aisle lights may be inoperative, provided the approved minimum regulatory required lighting levels are complied with. Portable Emergency Lights In addition to the fixed lights over the exits, there are portable emergency exit lights near the exits which have an internal battery pack. The light can be detached and used as a torch. 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 138 of 140 Warning and Caution Lighting Master warning and caution lights are “attention getters” and are used to alert the crew to system failures or abnormalities. Two colours are used: red and amber. Amber caution lights are to indicate a system abnormality requiring corrective action by the flight crew. It does not mean an unsafe condition and can be cancelled by pressing the master switch light. Red warning lights alert the crew to a condition which may affect the safety of the aircraft. These warnings require immediate crew action. The master warning illuminates continuously when activated and extinguishes when the condition is cleared. A new warning re-illuminates the master warning lights. Warning conditions include: Fire Overspeed Autopilot disconnect Configuration (take-off and landing) Cabin altitude Ground proximity warning and windshear. Master warning and master caution lights 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 139 of 140 Troubleshooting Lighting Systems The main fault in lighting systems is bulb failure. When checking light systems, always check that all bulbs in a multi-bulb lights are working before looking deeper into circuits. When checking lighting systems with an intensity control, check the system through the full intensity range. © Aviation Australia Emergency lighting schematic 2023-08-15 B1-11e Turbine Aeroplane Aerodynamics, Structures and Systems CASA Part Part 66 - Training Materials Only Page 140 of 140