時(shí)間：2011-04-18 00:47來(lái)源：藍(lán)天飛行翻譯 作者：航空 點(diǎn)擊：次
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2.Displaced Threshold. A displaced thresh-old is a threshold located at a point on the runway other than the designated beginning of the runway. Displacement of a threshold reduces the length of runway available for landings. The portion of runway behind a displaced threshold is available for takeoffs in either direction and landings from the opposite direction. A ten feet wide white threshold bar is located across the width of the runway at the displaced threshold. White arrows are located along the centerline in the area between the beginning of the runway and displaced threshold. White arrow heads are located across the width of the runway just prior to the threshold bar, as shown in FIG 2.3.4. NOTE. Airport operator. When reporting the relocation or displacement of a threshold, the airport operator should avoid language which confuses the two. i. Demarcation Bar. A demarcation bar delin-eates a runway with a displaced threshold from a blast pad, stopway or taxiway that precedes the runway. A demarcation bar is 3 feet (1m) wide and yellow, since it is not located on the runway as shown in FIG 2.3.6. 1. Chevrons. These markings are used to show pavement areas aligned with the runway that are unusable for landing, takeoff, and taxiing. Chevrons are yellow. (See FIG 2.3.7.)j. Runway Threshold Bar. A threshold bar delineates the beginning of the runway that is available for landing when the threshold has been relocated or displaced. A threshold bar is 10 feet (3m) in width and extends across the width of the runway, as shown in FIG 2.3.4. 2.3.4 Airport Marking Aids and Signs FIG 2.3.3 Relocation of a Threshold with Markings for Taxiway Aligned with Runway Airport Marking Aids and Signs 2.3.5 FIG 2.3.4 Displaced Threshold Markings 2.3.6 Airport Marking Aids and Signs FIG 2.3.5 Runway Shoulder Markings 2.3.4. Taxiway Markings a. General. All taxiways should have centerline markings and runway holding position markings whenever they intersect a runway. Taxiway edge markings are present whenever there is a need to separate the taxiway from a pavement that is not intended for aircraft use or to delineate the edge of the taxiway. Taxiways may also have shoulder markings and holding position markings for Instrument Landing System/Microwave Landing System (ILS/ MLS) critical areas, and taxiway/taxiway intersection markings. REFERENCE. AIM, Holding Position Markings, Paragraph 2.3.5. b. Taxiway Centerline. 1. Normal Centerline. The taxiway centerline is a single continuous yellow line, 6 inches (15 cm) to 12 inches (30 cm) in width. This provides a visual cue to permit taxiing along a designated path. Ideally, the aircraft should be kept centered over this line during taxi. However, being centered on the taxiway centerline does not guarantee wingtip clearance with other aircraft or other objects. AIM 2. Enhanced Centerline. At some airports, mostly the larger commercial service airports, an enhanced taxiway centerline will be used. The enhanced taxiway centerline marking consists of a parallel line of yellow dashes on either side of the normal taxiway centerline. The taxiway centerlines are enhanced for a maximum of 150 feet prior to a runway holding position marking. The purpose of this enhancement is to warn the pilot that he/she is approaching a runway holding position marking and should prepare to stop unless he/she has been cleared onto or across the runway by ATC. (See FIG 2.3.8.) c. Taxiway Edge Markings. Taxiway edge markings are used to define the edge of the taxiway. They are primarily used when the taxiway edge does not correspond with the edge of the pavement. There are two types of markings depending upon whether the aircraft is suppose to cross the taxiway edge: 1.Continuous Markings. These 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. They are used to define the taxiway edge from the shoulder or some other abutting paved surface not intended for use by aircraft. 2.Dashed Markings. These markings are used when there is an operational need to define the edge of a taxiway or taxilane 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. (See FIG 2.3.9.)d. Taxi Shoulder Markings. Taxiways, holding bays, and aprons are sometimes provided with paved shoulders to prevent blast and water erosion. Although shoulders may have the appearance of full strength pavement they are not intended for use by aircraft, and may be unable to support an aircraft. Usually the taxiway edge marking will define this area. Where conditions exist such as islands or taxiway curves that may cause confusion as to which side of the edge stripe is for use by aircraft, taxiway shoulder markings may be used to indicate the pavement is unusable. Taxiway shoulder markings are yellow. (See FIG 2.3.10.)Airport Marking Aids and Signs 2.3.7 FIG 2.3.6 Markings for Blast Pad or Stopway or Taxiway Preceding a Displaced Threshold 2.3.8 Airport Marking Aids and Signs FIG 2.3.7 Markings for Blast Pads and Stopways Airport Marking Aids and Signs 2.3.9 FIG 2.3.8 to the left being on the left side of the taxiway Enhanced Taxiway Centerline centerline and signs indicating turns to the right being on the right side of the centerline. (See FIG 2.3.11.)FIG 2.3.10 Taxi Shoulder Markings FIG 2.3.9 Dashed Markings DOUBLE YELLOW LINES TAXIWAY EDGE TAXIWAY EDGE MARKINGS MARKINGS CONTINUOUS DASHED e. Surface Painted Taxiway Direction Signs. Surface painted taxiway direction signs have a 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 adjacent to the centerline with signs indicating turns RUNWAY PAVEMENT EDGE YELLOW STRIPES TAXIWAY EDGE MARKINGS f.Surface Painted Location Signs. Surface painted location signs have a black background with a yellow inscription. When necessary, these markings are used to supplement location signs located along side 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. (See FIG 2.3.11.) |
