This preview shows page 1. Sign up to view the full content.
Unformatted text preview: P.3 AV 2.9 Lights ATA 33
ATA - 100 Chapter 033 deals with lighting. All aircrafts approved for flying at night must be equipped with various lights. External Lighting: 1. Marking of an A/C position by means of navigation lights. 2. Position marking by means of flashing lights. 3. Forward illumination for landing and taxiing. 4. Illumination of wings and engine air intakes to check for icing. 5. Illumination to permit evacuation of passengers after an emergency landing. Navigation\Positional Lights: Internationally accepted by statutory rules of air and orders for air traffic and air navigation control regulations. o A green light at or near star board or right wing tip- visible in the horizontal plane from a point directly ahead (forward motion) through an arc of 110° to star board. o A 'red' light at or near port or left wing tip with a similar arc of visibility (110°) to port. o A 'white' light usually mounted on the top of vertical stabilizer (fin) or aircraft tail. Their rear or aft position must show 700 on each side of the center line of the a/c and to the rear (140°). o White light mounted on each trailing wing tip for DC - 10 lock head 1011: Tri-Star a/c. o Lamp is of filament type with a transparent colored screen or cap. o These lights are operated with single circuit. One fuse or one CB and one switch. Anti collision lights: It is designed to make the presence of an a/c visible to pilot and crew members of other a/c in the vicinity. Particularly in area of high density aviation activity at night and in conditions or reduced visibility. These lights are mounted on the top of the fuselage. The top of the vertical stabilizer (for small a/c) and on the bottom of fuselage. Two basic type of anti collision lights (a) Rotating beacons (b) Strobe. Strobe lights have no moving parts and produces bright light. Rotating Beacons or Rotating Beam Lights: It consists of filament lamp unit with reflector and motor. Motor may drive deflector or lamp unit: Through gear and pinion type with specific reduction ratio. Light unit can be operated 28V DC or 28V AC: Motor 115V AC. Typical speed of motor 40-45 rev/min giving a frequency of 80-90 cycles per minute. Strobe Lights: It consists of quartz or glass tube filled with xenon gas. This is connected to the power supply unit consists of capacitor. Capacitor converts 28V DC or 115V AC in to high input DC of 450 Volts. Capacitor charges at this voltage and periodically discharged by trigger circuit between two electrodes in the xenon filled tube. Thus producing high intensity flash of light in the blue white color. It has got the frequency of 70 flashes per minute. The principle is capacitor discharge in flash tube or strobe scope. Strobe light can be used as anti collision system or at wing tips. The duration of flash is 0.001 Sec. intensity is more can be seen from miles. Fitted in such away light will not affect the vision of crew members. Anti collision lights if not installed by manufacturer, must be installed as per FAA publication Ac43-12-2A, regulation concerning such lights are provided in FAR part 23 and part 25. Landing Lights: These lights are required to provide adequate light to illuminate the run way when the a/c is making landing. A parabolic reflector is used to concentrate the light into the beam of desired width. These lights may be installed to the stationary part of nose gear, in the leading edges of the wings or engine cowl. Retractable landing lights in the lower surface of wings. Landing lamps have 600 watts capacity with a supply of 28V DC or 28V AC. Leading edge landing lamps can be turned on several miles away from landing. When the control s/w is placed in "Extend" position, 115V supply passes through extend field winding of motor until it is interrupted by extend limit s/w. retract limit s/w closes soon after motor extending the light. The s/w in the supply circuit to light also closes but light is not illuminated until it is fully extended and the control switch placed on position. Power supply to light reduced to 15V step down transformer. Taxiing Lights: Taxiing lights are also sealed beam type located on fuselage nose section (nose landing gear assembly). The power rating 250 watts at 28V DC or AC. Some of the A.C. landing / taxiing light filaments combined in one light having 600 watts and 400watts respectively. Some of larger transport aircrafts are equipped with lights as run way turn off lights. The Purpose is to illuminate the points along the runway at which a/c must turn to leave the runway after landing. Operated by switch and solenoid. ICE Inspection Lights: These lights are used to detect the formation of ice on the leading edges of wings and also at the air in takes of turbine engines. They are recessed into the side of fuselage and preset to direct the beams to at a required angle for rear mounted engines lights recessed to the trailing edges of wings. The power of lamps is 60 to 250 watts depending on light intensity. Logo lights are fitted in some aircrafts in the tail section facing towards the vertical fin. So, that the logo is visible at night. The rating is as per the manufacturer. Internal Lighting: 1. Illumination of cockpit instruments and control panels. 2. Illumination of passenger cabins, passenger in formation signs. 3. Indication and warning of system operating conditions. Flight desk or cockpit lighting: Normally white lighting is used because of because of advantages over red 1. The amount of electrical power required is reduced since red filters which absorb about 80% of the light eliminated. 2. Heat dissipation problems are reduced. 3. White lighting permits color coding of displays. Use of red warning flags and other similar indications. 4. Contrast between instrument display and readability is improved. 5. Eye fatigue is reduced. 6. Better illumination provided under thunder storm conditions. Cockpit or operational Lighting: Integral lighting is one in which light source is within instrument. These lights installed behind the face of instrument panel. These lights illuminate the instruments but do not shine directly towards the pilot or copilot. All instrument lights are shielded like this. These lights provide with dimming arrangement so intensity can be adjusted. Festoons of micro miniature lamps mounted in cluster around the inside of the instrument calling. It avoids removal of instruments for lamp replacement. Pillar and bridge lighting number of lights are positioned on panels to illuminate small adjacent areas. Flood lights lamps are positioned around the cockpit to illuminate specific panels or general area. Warning lights are provided to alert the pilot and crew to operating conditions within a/c systems. Red danger, Amber - caution , Green - safe condition, Information purpose White. Passenger Cabin Lighting: Depends up on size of cabin and largely on the interior decor adopted for the type of aircraft. can be carried from roof mounted incandescent lamp fittings to large number of fluorescent lamps located in ceilings and had racks to give pleasing Concealed and functional lighting effects. Works on DC or AC. Passenger service lighting fitted in galleys, toilet compartments, freight compartments and equipment bays. Lights can be incandescent type or fluorescent lamps, electro luminescent type lamps are used for passenger information signs like Fasten seat belts". Return to Cabin, are controlled by switches on cockpit over head panel. Passenger compartment lighting is controlled from cabin attendant. Cargo and baggage compartment, dome lights are providing evenly adjacent to doors. Dome light provide with protective guard. Service lighting/ Maintenance lights: General illumination for routine inspection and servicing in such areas wheel walls air conditioning compartments fail cone. APU compartment E&E bay. Generally explosion proof dome or bulk head type with conveniently located switches. Emergency Lighting: These lights are fitted at cabin exits escape hatches of lower levels. It provides lighting for emergency evacuation of passengers in situation like crash landing during night. These lights are controlled by emergency battery pack or air craft battery. Maintenance of lighting: At specified inspection periods or whenever serviceability of a light or lighting system is suspected. Check: Components for proper installation. Security mounting. Physical damage and any other evidence of over heading Terminal connections are secure freedom foreign matter moisture and corrosion Bonding connection for proper electrical contact & security Wiring for physical damage such as chafing, fraying, damaged insulation or contamination of harmful fluids (hydraulic) Fluorescent lighting: Three methods of light fitting. Butt type tube holder which has a movable center tab. Center tab is pressed outwards pins of bulb removed from holder Spring loaded movable tube holder at one end stationary tube holder other. Gentle pressure to pull out spring loaded to remove the bulb When the tube is rotated or turned in the tube holder for its removal or installation Precautions must be followed Strobe lighting: A minimum two minutes time must be given before working after disconnection of supply damage to eyes if see directly light of landing/strobe lights. Plastic fitting and fixture use of tools must be avoided only gentle hand pressure required to remove or install. Self illuminated signs: Radioactive (trilingual) breakage of glass envelope A/C should evacuate all doors must be open. Return parts to manufacture in case of breakage. Self illuminating sign must be returned to manufacture 05 years or breakage for disposal. ...
View Full Document
- One '11