Runway • Rectangular-shaped, paved surfaces on an airport, designed for the landing or takeoff of airplanes. • Runways may be a man-made surface (often asphaltconcrete, or a mixture of both) or a natural surface (grass, dirt, gravel, ice, or salt). Runway
Runway Designations • Based on a runway’s magnetic heading, using the 360 degree compass system • Runways may be used in two opposite directions • All runways have TWO runway designations
Runway Designations • The pictured runway is oriented in the north-south direction • The pictured runway would be designated Runway 18/36
Runway IncursionAvoidance • Definition of a Runway Incursion: • “any occurrence at an airport involving an aircraft, vehicle, person, or object on the ground that creates a collision hazard or results in loss of separation with an aircraft taking off or intending to land” • Primarily caused by errors associated with clearances, communication, airport surface movement, and positional awareness.
Examples of an incursion: • An aircraft or vehicle crossing in front of a: • landing aircraft or aircraft taking off • An aircraft or vehicle: • crossing the runway-holding position marking; • unsure of its position and entering an active runway; • passing behind an aircraft or vehicle that has not vacated the runway. • Failureto follow an air traffic control instruction
Runway length • A runway of at least 6,000 ft (1,800 m) in length is usually adequate for aircraft weights below approximately 200,000 lb (90,000 kg). • Larger aircraft including wide bodies will usually require at least 8,000 ft (2,400 m) at sea level and somewhat more at higher Altitude airports. • International wide body flights, which carry substantial amounts of fuel and are therefore heavier, may also have landing requirements of 10,000 ft (3,000 m) or more and takeoff requirements of 13,000 ft (4,000 m).
Runway length • At sea level, 10,000 ft (3,000 m) can be considered an adequate length to land virtually any aircraft. • An aircraft will need a longer runway at a higher altitude due to decreased density of air at higher altitudes, which reduces lift and engine power, requiring higher take-off and landing speed
Runway Surface Markings • Runway surface markings are white in colour
Runway Surface Markings The runway centerline is a broken white stripe which indicates the center of the runway and provides alignment guidance for aircraft.
Runway Surface Markings The runway edge-line is an unbroken white stripe indicating the edges of the runway, and the edges of the full-strength pavement.
Runway Surface Markings Runway threshold markings identify the beginning of the runway which is available for landing.
Runway Surface Marking • Displaced Threshold: • A threshold that is moved back usually due to obstructions, such as trees, powerlines, or buildings off the end of the runway. • This might prohibit you from making a normal descent to landing on the initial portion of the pavements.
Runway Markings • Displaced Threshold:
Runway Markings • Blast Pad/Stopway Area: • Sometimes referred to as an overrun, it is different from the area preceding a displaced threshold because it cannot be used for landing, takeoff, or taxiing. • The blast pad is where propeller or jet blast can dissipate without creating a hazard to others. • The “overrun” aspect comes in the fact that the blast pad is paved, allowing aircraft more room to come to a stop after an aborted takeoff.
Runway Markings • Blast Pad/Stopway Area:
Runway Lighting • Runway Edge Lights:- • Single row of white lights bordering each side of runway and lights identifying the runway threshold • Three Intensity Levels: High Intensity (HIRLs), Medium Intensity runway lights (MIRLs), and Low intensity runway lights (LIRLs) • Elevated edge-lights identify the runway edges during adverse visibility conditions • Some are Pilot Controlled, some ATC controlled
Approach Lighting Systems • REILs (Runway End Identifier Lights) • High intensity white strobe lights that are places on each side of the runway to mark the threshold.
Approach Lighting Systems • In-Runway Lighting • Some precision approach lighting systems have lights mounted flush with the surface of the runway. • The runway centerline lighting system (RCLS) is white until the last 3,000 ft. • From the 3,000 ft. point to the 1,000 ft. point, alternating red and white lights appear. • The remaining 1,000 ft. are red lights. • Touchdown Zone Lighting • Two rows of transverse light bars on either side of the runway centerline starting at 100 ft. from the threshold and extending 3,000 ft. or to the midpoint of the runway.
Approach Lighting Systems • In -Runway Lighting:
Taxiways • A paved surface designed for the movement of aircraft from one part of the airport to another
Taxiway Surface Markings ALL taxiway surface markings are yellow. Taxiway centerline markings indicate the center of the taxiway.
Taxiway Surface Markings • Double yellow taxiway edge-lines indicate the edges of the taxiway as well as the edge of full-strength pavement
Taxiway Surface Markings • Taxiway Shoulder Markings consist of transverse stripes extending from the taxiway edge markings into paved areas which are not intended for aircraft use • paved areas which are unsuitable for • aircraft may be painted green.
Taxiway Surface Markings • Runway Hold Lines are located on taxiways which intersect runways • All aircraft and vehicles must hold short of the runway at the hold line.
Taxiway Surface Markings Hold Lines are located at the intersection of a taxiway and a runway. • Aircraft/vehicles must hold on the solid side of the hold line.
Taxiway Lighting Taxiway edge-lights are blue in color • Taxiway edge lighting identifies the edge of a taxiway during periods of darkness or reduced visibility.
Taxiway Lighting Taxiway Lighting In-pavement: Taxiway centerline lights are green in color
Taxiway Lighting Runway Guard Lights • Two Types: Elevated and In-Pavement • Elevated Runway Guard Lights consist of two alternating, flashing yellow lights
Taxiway Lighting Runway Guard Lights • In-pavement Runway Guard Lights consist of flashing yellow lights, which extend across the taxiway, parallel to the hold line
Taxiway Lighting In-pavement Runway Guard Lights Extend across hold line
(VASI) Visual Approach Slope Indicator
Taxilanes (Alleys/Alleyways) A paved surface used for access between taxiways and Ramp (gate) areas
TaxilaneSurface Markings Taxilanes have either solid white or yellow lead-in lines
Ramp/Apron Area Surface Markings Wing-clearance lines are white or red.
Active Runway • The active runway is the runway at an airport that is in use for takeoffs and landings. Since takeoffs and landings are usually done as close to "into the wind" as possible, wind direction generally determines the active runway. • Selection of the active runway, however, depends on a number of factors. At a non-towered airport, pilots usually select the runway most nearly aligned with the wind, but they are not obliged to use that particular runway. • At controlled airports, the active is usually determined by a tower supervisor.
Active runway • At major airports with multiple runways, the active could be any of a number of runways. • At major airports, the active runway is based on weather conditions (visibility and ceiling, as well as wind, and runway conditions such as wet/dry or snow covered), efficiency, traffic demand and time of day
Section of runway • The Runway Safety Area is the cleared, smoothed and graded area around the paved runway. It is kept free from any obstacles that might impede flight or ground roll of aircraft. • The Runway is the surface from threshold to threshold, which typically features threshold markings, numbers, centerlines, but not overrun areas at both ends.
Runway safety • Types of runway safety incidents include: • Runway excursion - an incident involving only a single aircraft, where it makes an inappropriate exit from the runway. • Runway overrun - a type of excursion where the aircraft is unable to stop before the end of the runway • Runway incursion- an incident involving incorrect presence of a vehicle, person or another aircraft on the runway • Runway confusion - an aircraft makes use of the wrong runway for landing or take-off
Pavement • The choice of material used to construct the runway depends on the use and the local ground conditions. • For a major airport, where the ground conditions permit, the most satisfactory type of pavement for long-term minimum maintenance is concrete.
Pavement • Although certain airports have used reinforcementin concrete pavements, this is generally found to be unnecessary, with the exception of expansion jointsacross the runway where a dowel assembly, which permits relative movement of the concrete slabs, is placed in the concrete • Post-tensioning concrete has been developed for the runway surface. This permits the use of thinner pavements and should result in longer concrete pavement life.
Pavement surface • Runway pavement surface is prepared and maintained to maximize friction for wheel braking. • To minimize hydroplaning following heavy rain, the pavement surface is usually grooved so that the surface water film flows into the grooves and the peaks between grooves will still be in contact with the aircraft tires.
Surface Type Codes • In aviation charts, the surface type is usually abbreviated to a three-letter code. • The most common hard surface types are Asphalt and Concrete. The most common soft surface types are Grass and Gravel. • ASP: Asphalt • BIT: Bituminous Asphalt or Tarmac • BRI: Bricks (no longer in use, covered with Asphalt or Concrete now) • CLA: Clay • COM: Composite • CON: Concrete • COP: Composite • GRS: Grass or earth not graded or rolled • COR: Coral (Coral reef structures) • GRE: Graded or rolled earth, Grass on graded earth • GVL:Gravel • LAT: Laterite • ICE: Ice • MAC:Macadam • PEM: Partially Concrete, Asphalt or Bitumen-bound Macadam • PER: Permanent Surface, Details unknown • PSP: Marsden Matting(Derived from Pierced/Perforated Steel Planking) • SAN: Sand • SNO: Snow • U: Unknown surface
Runway markings • There are runway markings and signs on most large runways. Larger runways have a distance remaining sign (black box with white numbers). This sign uses a single number to indicate the thousands of feet remaining, so 7 will indicate 7,000 ft (2,134 m) remaining. The runway threshold is marked by a line of green lights.
Runway markings • There are three types of runways: • Visual runways are used at small airstrips and are usually just a strip of grass, gravel, asphalt or concrete. Although there are usually no markings on a visual runway, they may have threshold markings, designators, and centerlines. Additionally, they do not provide an instrument-based landing procedure; pilots must be able to see the runway to use it. Also, radio communication may not be available and pilots must be self-reliant. • Non-precision instrument runways are often used at small- to medium-size airports. These runways, depending on the surface, may be marked with threshold markings, designators, centerlines, and sometimes a 1,000 ft (305 m) mark (known as an aiming point, sometimes installed at 1,500 ft (457 m)). They provide horizontal position guidance to planes on instrument approach via Non-directional beacon (NDB), VHF omnidirectional range (VOR), Global Positioning System, etc.
Runway markings • Precision instrument runways, which are found at medium- and large-size airports, consist of a blast pad/stopway,threshold, designator, centerline, aiming point, and 500 ft (152 m), 1,000 ft (305 m)/1,500 ft (457 m), 2,000 ft (610 m), 2,500 ft (762 m), and 3,000 ft (914 m) touchdown zone marks. Precision runways provide both horizontal and vertical guidance for instrument approaches.
REFERENCES • Airport Planning & Design by Khanna & Arora