时间：2011-04-18 00:47来源：蓝天飞行翻译 作者：航空 点击：次
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2.To provide radar traffic advisories. Radar traffic advisories may be provided to the extent that the local controller is able to monitor the radar display. Local control has primary control responsibi-lities to the aircraft operating on the runways, which will normally supersede radar monitoring duties. 3.To provide a direction or suggested heading. The local controller may provide pilots flying VFR with generalized instructions which will facilitate operations; e.g., “PROCEED SOUTH-WESTBOUND, ENTER A RIGHT DOWNWIND RUNWAY THREE ZERO,” or provide a suggested heading to establish radar identification or as an advisory aid to navigation; e.g., “SUGGESTED HEADING TWO TWO ZERO, FOR RADAR IDENTIFICATION.” In both cases, the instructions are advisory aids to the pilot flying VFR and are not radar vectors. NOTE. Pilots have complete discretion regarding acceptance of the suggested headings or directions and have sole responsibility for seeing and avoiding other aircraft. 4. To provide information and instructions to aircraft operating within Class B, Class C, and Class D surface areas. In an example of this situation, the local controller would use the radar to advise a pilot on an extended downwind when to turn base leg. NOTE. The above tower radar applications are intended to augment the standard functions of the local control position. There is no controller requirement to maintain constant radar identification. In fact, such a requirement could compromise the local controller’s ability to visually scan the airport and local area to meet FAA responsibilities to the aircraft operating on the runways and within the Class B, Class C, and Class D surface areas. Normally, pilots will not be advised of being in radar contact since that continued status cannot be guaranteed and since the purpose of the radar identification is not to establish a link for the provision of radar services. e. A few of the radar equipped towers are authorized to use the radar to ensure separation between aircraft in specific situations, while still others may function as limited radar approach controls. The various radar uses are strictly a function of FAA operational need. The facilities may be indistinguishable to pilots since they are all referred to as tower and no publication lists the degree of radar use. Therefore, when in communication with a tower controller who may have radar available, do not assume that constant radar monitoring and complete ATC radar services are being provided. 4.3.3. Traffic Patterns At most airports and military air bases, traffic pattern altitudes for propeller-driven aircraft generally extend from 600 feet to as high as 1,500 feet above the ground. Also, traffic pattern altitudes for military turbojet aircraft sometimes extend up to 2,500 feet above the ground. Therefore, pilots of en route aircraft should be constantly on the alert for other aircraft in traffic patterns and avoid these areas whenever possible. Traffic pattern altitudes should be maintained unless otherwise required by the applicable distance from cloud criteria (14 CFR Section 91.155). (See FIG 4.3.2 and FIG 4.3.3.) 4.3.2 Airport Operations FIG 4.3.2 Traffic Pattern Operations Single Runway EXAMPLE. Key to traffic pattern operations 1.Enter pattern in level flight, abeam the midpoint of the runway, at pattern altitude. (1,000’ AGL is recommended pattern altitude unless established otherwise.)2. Maintain pattern altitude until abeam approach end of the landing runway on downwind leg. 3.Complete turn to final at least 1/4 mile from the runway. 4.Continue straight ahead until beyond departure end of runway. 5.If remaining in the traffic pattern, commence turn to crosswind leg beyond the departure end of the runway within 300 feet of pattern altitude. 6.If departing the traffic pattern, continue straight out, or exit with a 45 degree turn (to the left when in a left.hand traffic pattern; to the right when in a right.hand traffic pattern) beyond the departure end of the runway, after reaching pattern altitude. Airport Operations 4.3.3 FIG 4.3.3 Traffic Pattern Operations Parallel Runways EXAMPLE. Key to traffic pattern operations 1.Enter pattern in level flight, abeam the midpoint of the runway, at pattern altitude. (1,000’ AGL is recommended pattern altitude unless established otherwise.)2. Maintain pattern altitude until abeam approach end of the landing runway on downwind leg. 3.Complete turn to final at least 1/4 mile from the runway. 4.Continue straight ahead until beyond departure end of runway. 5.If remaining in the traffic pattern, commence turn to crosswind leg beyond the departure end of the runway within 300 feet of pattern altitude. 6.If departing the traffic pattern, continue straight out, or exit with a 45 degree turn (to the left when in a left.hand traffic pattern; to the right when in a right.hand traffic pattern) beyond the departure end of the runway, after reaching pattern altitude. 7.Do not overshoot final or continue on a track which will penetrate the final approach of the parallel runway. 8.Do not continue on a track which will penetrate the departure path of the parallel runway. 4.3.4 Airport Operations 4.3.4. Visual Indicators at Airports Without an Operating Control Tower a. At those airports without an operating control tower, a segmented circle visual indicator system, if installed, is designed to provide traffic pattern information. REFERENCE. AIM, Traffic Advisory Practices at Airports Without Operating Control Towers, Paragraph 4.1.9. b. The segmented circle system consists of the following components: 1.The segmented circle. Located in a position affording maximum visibility to pilots in the air and on the ground and providing a centralized location for other elements of the system. |
