Additional visual aids to navigation consist of markings on the aerodromes. These markings comprise single lines or rows of lines which, for the pilot, are very important for holding positions, runway thresholds, the runway centre lines, the sides of the runways, etc. etc…
However, at night or during poor visibility by day, lights are required. For lights to be effective they must be of adequate intensity. (1)At certain aerodromes the controller can vary the intensity of some of the lights so that they can be reduced to avoid momentarily blinding the pilot and strong enough so that he can see them in thick weather.
The first light a pilot sees on approach is generally the aerodrome beacon. (2) It may rotate(3)and can be seen at a great distance distinguishable by its coloured flashes(4)alternating with white, or white only. There might be an identification beacon(5)which shows green flashes of light which identify the aerodrome in morse code. (6) Red lights, the usual danger signal, warn pilots of the obstacles such as hangers and other high buildings, telephone poles, etc. Runway edge lights(7)identify the runway and approach lights assist the pilot to align(8) himself with the runway.
Lights may also be used to provide a glide path similar to what an ILS provides electronically. The Visual Approach Slope Indicator System, better known as VASIS(9), is a beam of light having a white colour in its upper part and a red colour in its lower part. A pilot of an aeroplane during an approach will:
a) when above the approach slope, see the lights to be white in colour;
b) when on the approach slope, see the lights to be pink in colour; and
c) when below the approach slope, see the lights to be red in colour.
By reference to VASIS, combined with ILS, the pilot can bring an aircraft down safely almost to touchdown by day or night.
After landing, he follows the blue taxi lights along the taxiway to the apron and the service areas.
At the service area a marshaller(10)with illuminated wands (11,12), directs the aircraft with signals to its proper position for unloading and, finally, signals pilot to cut his engines.(13)
─ Level of brightness.
2. Aerodrome beacon
─ Aerodrome light used to indicate the location of an aerodrome from the air.
3. To rotate:
─ To revolve; move round axis or centre.
─ Lights that go on and off.
5. Identification beacon
─ A light identifying an aerodrome.
6. Morse code
─ Signal by long or short flashes when lights are used and by dots and dashes when telegraph is used.
7. Runway edge
─ The sides of the runway.
8. To align
─ To bring into line.
─ Visual Approach Slope Indicator System. A glide path formed by lights.
─ The signaller who directs the pilots on the apron.
11. To illuminate
─ To light up, to make visible in the dark.
─ Illuminated sticks used by the marshaller.
13. To cut engines
─ To stop engines.
1. Can I control the brightness or intensity of the lights in this room? Who controls the intensity of the lights .at an aerodrome? Is the intensity of the lights high in thick weather? Could high intensity lights momentarily blind the pilot? When lights momentarily blind the pilot, what does he ask the controller to do?
2. A beacon is a signal light. Is an aerodromebeacon also a light? Are there many beacons at an aerodrome? Are aerodrome beacons lit at night? During the day? Are aerodrome beacons lit every day? Is an aerodrome beacon of high intensity or low intensity? Can you see the aerodrome beacon from the road? Who sees the aerodrome beacon? Is it necessary for the intensity of the light of the aerodrome beacon to be high? Is the pilot far from or close to the aerodrome when he first sees the aerodrome beacon?
3. Does a wheel rotate? Does the steering wheel in a car rotate? What wheel rotates? Does a pilot distinguish an aerodrome beacon because it rotates? Do runway lights rotate? Taxiway lights? What light rotates?
4. Are signals flashes of lights? Is a continuous light a flash? What do you do to have flashes of light?
5. Does an identification beacon also flash a coloured light? Can the flashes of an identification beacon be seen by the pilot? By the radar controller? Who sees the flashes of the identification beacon? By night? By day? Why is it necessary for the pilot to see the identification beacon?
6. Morsecode is a signal. Can we signal by morse code with sounds? By light? By telegraph? Who uses morse code with light signals? What lamp does the controller use when he signals by morse code? What beacon identifies the aerodrome with morse code?
7. Are the runwayedges on both sides of the runway? Are there two runway edges on each runway? Three? How many runway edges are there? Where are the runway edges? Why do runway edges have lights? Markings? Are the runway edge markings long or short?
8. When a pilot approaches an aerodrome does he align his plane with the runway? With the perimeter? With the boundary? With what does he align his plane? When does a pilot align his plane with the runway?
9. VASIS is a system which projects a beam of light. Is VASIS a glide path formed by lights? Markings? Electronics? What sort of glide path is VASIS? Is VASIS used as a landing aid? To take off? When is VASIS used? How many different colours of lights does VASIS have?
10. Is a marshaller the person who directs aircraft on the apron? Does the marshaller signal the pilot? Does the marshaller signal him to stop? To come forward? Turn left? Turn right? Where is the marshaller when he signals the pilot?
11. If I want to illuminate this room, I put on the lights. Do people illuminate buildings? Trees? Do they use one light or many to illuminate a park? An aerodrome? At what time do they illuminate this city? This aerodrome?
12. At night wands are used by the marshaller. How many wands does the marshaller have? Does the marshaller wave the wands? Does he point the wands to the left? Right? Up? Down? Are these wands illuminated? By night? By day? Does a marshaller always use wands? When does the marshaller use wands? Why does the marshaller use wands?
13. Does the marshaller signal the pilot to cut his engines? When the pilot cuts the engines, do the engines still function? Do the engines continue to make a noise when they are cut? What happens when the pilot cuts the engines? Does the marshaller cut the engine? Who cuts the engines? Where is the marshaller when he asks the pilot to cut the engines?
Instructions to students: Choose the appropriate meaning or meanings, if more than one meaning applies. Mark the square accordingly.
A vector is
a.) a navaid
b.) a landing aid.
c.) a beacon.
d.) a heading given by the controller.
A controller can
a.) vary the intensity of the aerodrome beacon.
b.) vary the intensity of the runway lights.
c.) signal in morse code.
d.) turn on the lights of the runway in use.
a.) are on the runway threshold.
b.) are on the taxiways.
c.) can be seen at a great distance.
d.) can be seen in poor visibility.
a.) permit a pilot to align his aircraft
b.) with the runway.
c.) are seen below the glide path.
d.) can be seen at a great distance.
e.) are seen just before touchdown.
A beacon is
a.) a row of lights.
b.) a light of high intensity.
c.) like a search light.
d.) the light from a flash light.
A beam of light
a.) can illuminate all angles at the same time
b.) is confined to one area at a time.
c.) is a morse code signal.
d.) if directed at you, can be momentarily blinding.