F-22 Raptors taxiing at Elmendorf AFB, Alaska, USA

A taxiway is a path on an airport connecting runways with ramps, hangars, terminals and other facilities. An Air Force Base ( AFB) is a Military base of any of a number of Air forces including the United States Air Force (USAF and the South African An airport is a location where Aircraft such as airplanes, Helicopters and blimps take off and land A runway ( RWY) is a strip of land on an Airport, on which Aircraft can take off and land. The airport ramp or apron is part of an Airport. It is usually the area where Aircraft are parked unloaded or loaded refueled or boarded A hangar is an enclosed structure to hold Aircraft in protective storage An airport terminal is a building at an Airport where passengers transfer between ground transportation and the facilities that allow them to board and disembark from Airplanes They mostly have hard surface such as asphalt or concrete, although smaller airports sometimes use gravel or grass. Asphalt ( is a sticky black and highly viscous liquid or semi-solid that is present in most crude Petroleums and in some natural deposits sometimes termed asphaltum Concrete is a construction material composed of Cement (commonly Portland cement) as well as other cementitious materials such as Fly ash and Slag Gravel is rock that is of a specific Particle size range In Geology, gravel is any loose rock that is larger than two millimeters (2mm Grass is the common word that generally describes Monocotyledonous green Plants The family Gramineae ( Poaceae) are the "true grasses" and include

Busy airports typically construct high-speed or rapid-exit taxiways in order to allow aircraft to leave the runway at higher speeds. This allows the aircraft to vacate the runway quicker, permitting another to land in a shorter space of time.

Taxiway markings

• Normal Centerline. A single continuous yellow line, 6 inches (15 cm) to 12 inches (30 cm) in width.
• Enhanced Centerline. The enhanced taxiway centerline marking consists of a parallel line of yellow dashes on either side of the taxiway centerline. Taxiway centerlines are enhanced for 150 feet (45. 7 m) prior to a runway holding position marking. The enhanced taxiway centerline is standard^[1] at all FAR Part 139 certified airports. The Federal Aviation Regulations, or FAR s are rules prescribed by the Federal Aviation Administration (FAA governing all Aviation activities in the
• Taxiway Edge Markings. Used to define the edge of the taxiway when the taxiway edge does not correspond with the edge of the pavement. Continuous Markings consist of a continuous double yellow line, with each line being at least 6 inches (15 cm) in width spaced 6 inches (15 cm) apart and define the taxiway edge from the shoulder or some other abutting paved surface not intended for use by aircraft. Dashed Markings. define the edge of a taxiway on a paved surface where the adjoining pavement to the taxiway edge is intended for use by aircraft, e. g. , an apron. Dashed taxiway edge markings consist of a broken double yellow line, with each line being at least 6 inches (15 cm) in width, spaced 6 inches (15 cm) apart (edge to edge). These lines are 15 feet (4. 5 m) in length with 25 foot (7. 5 m) gaps.
• Taxi Shoulder Markings. Taxiways, holding bays, and aprons are sometimes provided with paved shoulders to prevent blast and water erosion. Shoulders are not intended for use by aircraft, and may be unable to carry the aircraft load. Taxiway shoulder markings are yellow lines perpendicular to taxiway edge, from taxiway edge to pavement edge, about 10 feet apart.
• Surface Painted Taxiway Direction Signs. Yellow background with a black inscription, and are provided when it is not possible to provide taxiway direction signs at intersections, or when necessary to supplement such signs. These markings are located on either side of the taxiway centerline.
• Surface Painted Location Signs. Black background with a yellow inscription. When necessary, these markings supplement location signs located alongside the taxiway and assist the pilot in confirming the designation of the taxiway on which the aircraft is located. These markings are located on the right side of the centerline.
• Geographic Position Markings. These markings are located at points along low visibility taxi routes (when RVR is below 1200 feet(360m)). Runway Visual Range (RVR is a term used in Aviation Meteorology to define the distance over which a pilot of an aircraft on the centreline of the runway can see the They are positioned to the left of the taxiway centerline in the direction of taxiing. Black inscription centered on pink circle with black inner and white outer ring.

• Runway Holding Position Markings. For runways, these markings indicate where an aircraft is supposed to stop when approaching a runway. They consist of four yellow lines, two solid and two dashed, spaced six or twelve inches apart, and extending across the width of the taxiway or runway. The solid lines are always on the side where the aircraft is to hold. There are three locations where runway holding position markings are encountered: Runway holding position markings on taxiways, runway holding position markings on runways, taxiways located in runway approach areas.
• Holding Position Markings for Instrument Landing System (ILS). The Instrument Landing System (ILS is a ground-based Instrument approach system that provides precision guidance to an Aircraft approaching a Runway These consist of two yellow solid lines spaced two feet apart connected by pairs of solid lines spaced ten feet apart extending across the width of the taxiway.
• Holding Position Markings for Taxiway/Taxiway Intersections. These consist of a single dashed line extending across the width of the taxiway.
• Surface Painted Holding Position Signs. Red background signs with a white inscription and supplement the signs located at the holding position.

The taxiways are given alphanumeric identification. These taxiway IDs are shown on black and yellow signboards along the taxiways.

Taxiway lights

Taxiway Light

For night operations, taxiways at many airports are equipped with lights, although some small airports are not equipped with them

• Taxiway Edge Lights. used to outline the edges of taxiways during periods of darkness or restricted visibility conditions. These fixtures are elevated and emit blue light. Blue is a Colour, the Perception of which is evoked by
• Taxiway Centerline Lights. They are steady burning and emit green light located along the taxiway centerline
• Clearance Bar Lights. Three in-pavement steady-burning yellow lights installed at holding positions on taxiways
• Runway Guard Lights. Either a pair of elevated flashing yellow lights installed on either side of the taxiway, or a row of in-pavement yellow lights installed across the entire taxiway, at the runway holding position marking at taxiway/runway intersections.
• Stop Bar Lights. A row of red, unidirectional, steady-burning in-pavement lights installed across the entire taxiway at the runway holding position, and elevated steady-burning red lights on each side used in low visibility conditions (below 1,200 ft RVR). A controlled stop bar is operated in conjunction with the taxiway centerline lead-on lights which extend from the stop bar toward the runway. Following the ATC clearance to proceed, the stop bar is turned off and the lead-on lights are turned on.

Taxiway lights are spaced 75 feet apart. In some airports, the lights are closer at the intersections.

References

External links

See also

• Aviation
• Runway