3 Airport Visual Aids Runway markings Runways with precision approaches and with non-precision approaches Displaced threshold Blast pad / stopway NOTAM
4 Runway Markings (1) Runway markings vary between runways used only for VFR and those that can be used both for VFR and IFR. A runway used for VFR alone usually is marked with only the runway number and the dashed white centerline. A runway that can be used for IFR has markings that allows pilots to navigate to the runway using only the flight instruments In this lecture we focus on runways that can be used both for IFR and VFR.
5 Runway Markings (2) – Precision & Nonprecision Approaches Runways for IFR can have two types of approach guidance - those using electronic glide slope to guide landing are said to use precision approaches. IFR runways that do not have electronic glideslope are said to use nonprecision approaches. IFR runways with nonprecision approaches also have somewhat different runway markings from those for precision approaches.
6 Runway Markings (3) – Precision & Nonprecision Approaches A runway using nonprecision instrument approach has a threshold and aiming point markings. In addition to the threshold and aiming point markings, precision approach runways also include touchdown zone markings. (Fig 4-17)
8 Runway Markings (4) – Displaced Threshold Sometimes a runway might be obstructed by buildings or other objects near the end. In such case the initial part cannot be used for landing and the threshold is displaced forward and a solid white line is added as the beginning of the threshold. Landing has to be done starting or beyond the threshold. The initial part is marked with white arrows. It cannot be used for landing but can be used for taxiing, takeoff, and as landing rollout. (Fig 4-18)
9 Displaced Threshold (4-18)
10 Runway Markings (4) – Blast Pad / stopway A blast pad / stopway looks similar to the initial part preceding a displaced threshold, except that the markings are yellow inverted-V s instead of white arrows. However it cannot be used for takeoff or even for taxiing. The area can only be used for decelerating after an aborted takeoff or an abnormal landing from the other side. In this area jet blast dissipation will not affect others. (Fig 4-19)
11 Blast Pad / stopway (4-19)
12NOTAM If a runway has to be closed unexpectedly and there is not enough time to publish the information on standard operational publications, a Notice to Airmen (NOTAM) may be issued to pilots about the closure. Also, NOTAMs can include changes in the status of navigational aids or instrument approach facilities, radar service availability, or other information ensential for landing operations.
13 Airport Visual Aids Taxiway markings Taxiway marks Ramp area hand signals
14 Taxiway Markings The links between the runway and the parking areas for airplanes are the taxiways. A taxiway can easily be identified with its continuous yellow centerline. In some airports, edge marking are added to separate the taxiway from pavements that are not for airplane driving. When a taxiway intersects a runway a hold line is drawn to prevent airplanes from wrongly entering the runway. (4-21)
15 Taxiway marking and Hold Line (4-21)
16 Ramp Area The area where airplanes park are called the apron or ramp area. Airport terminals and maintenance facilities are often located near the ramp area. Standard hand signals are used by ramp personnel for directing pilots during airplane ground movements and ground operations (called Fix Base Operations or FBOs). (Fig 4-23)
17 Standard Hand Signals (4-23)
18 Airport Visual Aids Taxiway markings Taxiway marks Ramp area hand signals
19 Airport Signs The International Civil Aviation Organization (ICAO) is a United Nations Agency that develop standard airport signs. The standard specification of these signs include their size, height, where the signs should be put, and their illumination. There are six basic types of airport signs. (Fig 4-24) Some example of sign use is in Fig 4-25.
23 Airport Beacon Lights which might have different colors and might change with time that are specifically used to guide pilots flying to airports in the dark are called airport beacons. (Fig 4-27) These beacons are most noticeable from one to ten degrees above the horizon. (Remember that standard landing is at 3 )
24 Airport Beacon (4-27)
25 Visual Glideslope Indicators (1) Visual glideslope indicators are light systems to let you know your position in relation to the desired glide path in landing to the runway. They are located on the side of the runway and can be used both during the day and at night. One typical type is the visual approach slope indicator (VASI).
26 Visual Glideslope Indicators (2) VASI may have either 2 or 3 bars (rows) of lights. A 2-bar system has one near and one far bar. Each bar can contain 2, 4 or 12 light units. If both bars show white lights, you are too high for your landing. If both bars show red, you are too low. If the far bar is red and the near bar is white you are just right. (Fig 4-28)
27 2-Bar VASI (4-28)
28 Visual Glideslope Indicators (4) - Tri-color VASI Tri-color VASI uses a single light unit that projects a three-color visual path. If while descending you see an amber light you are too high. If you see a green light you are right on the glide path. If you see red you are too low for correct landing. (Fig 4-29)
29 Tri-color VASI (4-29)
30 Visual Glideslope Indicators (5) - PAPI Some airport uses the precision approach path indicator (PAPI) which uses 2 or 4 lights in a row (instead of the two lights used in a VASI) and is put on the left side of the runway. In a 4-light system if all lights are white you are too high. If there are 3 white light and one red you are slightly high. If there are 2 white lights and 2 red ones you are just right. (and so on) (Fig 4-30)
31 The PAPI (4-30)
32 Runway Edge Lights (1) Runway edge lights consists a row of lights on each side of the runway, plus lights identifying the runway threshold. At some airports the pilot can adjust the intensity of these runway lights from the cockpit using the radio transmitter. Some runway edge lights incorporates yellow runway remaining lights on the last half of the runway (or the last 2000 feet of the runway, whichever is less).
33 Runway Edge Lights (2) In some runways the threshold lights might be replaced with a row of green lights across the beginning of the runway. These green lights are actually two-ways. When viewed from the other side of the runway (for planes taking off or landing from the opposite direction) they are red in color, indicating the end of the runway from that direction. Sometimes high intensity strobe lights are placed on each side of the runway at the threshold and can be used together with the green threshold lights.
34 In-Runway Lighting (1) Some precision approach runways have flush-mounted (level with the ground) lightings for the runway centerline, the touchdown zone, and taxiway turnoff area. The runway centerline lighting system (RCLS) is white until the last 3000 feet. From the 3000 to 1000-foot point, the lights are alternating between red and white. In the last 1000 feet the lights are all red. The pilot thus knows about how much runway is left for used.
35 In-Runway Lighting (2) Touchdown zone lighting (TDZL) consists of two rows of transverse light bars on either side of the runway centerline starting at 100 feet from the threshold and extends to 3000 feet (or extends over half the length of the runway, whichever is less).
36 Taxiway Lighting Taxiways are lined with blue lights on both sides to guide the pilot on the taxiway from the runway to the ramp area. At some airports taxiways are also installed with green centerline lights in addition to the blue lights on the edges.
37 Obstruction Lighting Obstruction lighting is used both on and off the airport, during day and night. They are used to warn pilots of large structures such as towers, buildings, and sometimes even powerlines. Bright red and high intensity white lights are typically used, and sometimes flashing lights are employed. Fig 4-23 displays different runway, taxiway, and obstruction lightings.
38 Summary of typical large airport lightings (4-32)
39 Aeronautical Charts Latitude and Longitude Projections
40 Latitude and Longitude (1) A pilot has to know the earth in detail while planning the flight or during flying to get to the destination. He/she depends on aeronautical charts (detailed maps) for these purposes. Between the north pole and the south pole, the earth is divided into horizontal parallel lines called latitudes. The largest circle is the equator which is mid-way between the two poles and is labeled as 0 latitude.
41 Latitude and Longitude (2) The parallel circular lines north from the equator are numbered from 0 to 90, with 90 north latitude being at the north pole. Similarly, the parallel latitude lines south of the equator are also numbered from 0 to 90, with 90 south latitude being at the south pole.
42 Latitude and Longitude (3) Vertical imaginary lines joining the north and the south pole are called longitudes. The longitude that passes Greenwich, England is labeled 0 longitude (called the Prime Meridian). The hemisphere east of Greenwich is divided into 180 of longitude, and the hemisphere west of Greenwich is similarly divided into 180.
43 Aeronautical Chart The lines of latitude and longitude are printed on an aeronautical chart. Each degree in latitude and longitude is sub-divided into 60 parts called minutes. Thus the earth is divided into 360x60 or 21,600 parts both on the east-west direction and on the north-south direction on an aeronautical chart. (Fig 4-34)
44 Latitude and Longitude on Aeronautical Chart (4-34)
45 Projections (1) When printing the aeronautical chart the 3-dimensional earth has to be projected into a 2-dimensional map. In our everyday wall map, both the latitudes and longitudes are projected as parallel straight lines onto the map. However in such projection the distances are greatly distorted as a very short distance near the poles that crosses 30 longitudes will appear much longer on the map.
46 Wall map projection (4-35)
47 Projections (2) To minimize the distortion problem aeronautical charts uses a different way of projection called Lambert Conformal Conic projection. (Fig 4-36) Aeronautical charts for VFR often show more details of the earth than those used for IFR.
48 Conic projection for aeronautic charts (4-36)