Section Name
ONE RUNWAY AIRPORT SEPARATIONS
Ing. Matej ANTOŠKO, PhD.
Ing. Peter KORBA, PhD.
Ing. Jozef SABO, PhD.
Faculty of Aeronautics of Technical University Košice, Košice, Slovakia
ABSTRACT
The article deals with the basic methods of radar vectoring of aircraft to the airports with one runway, contains six procedures for correct vectoring aircraft to initial approach point so as to achieve greatest use of airspace. Procedures contains radar vectoring of aircraft via single point and via two points. Part of the article also deals about solution during an emergency situation in zone of responsibility of air traffic controller situated at the approach control services. Two sections of article gives instructions how to reduce separations between aircraft and one section shows how to ensure separation by standard 360° turn. Every section of article is supplemented by graphical solution of air situation. The article offers instructions for air traffic controllers how to vectors aircraft to airports with one runway.
Keywords: air traffic control, radar control, emergency
Section Name
INTRODUCTION
During increased traffic at the airport is necessary to arrange aircraft in sequence to ensure air traffic flow management for the most efficient use of airspace. Many national and international regulations deals with radar vectoring. We have created procedures for simplification of the air traffic contollers (ATCo) training phase.
1. VECTORING VIA SINGLE POINT
Radar vectoring via a single point is the most common way and the simplest kind of radar vectoring to land at the airports with one runway. Figure 1 shows a vectoring of aircraft though the Final Approach Point (FAP). Minimums of vertical separations in control zone is 1000 ft and minimums of horizontal separations in control zone is 5 nautical miles. During radar vectoring is separation ensured if at least one condition is true.
During a training phase it is preferable for ATCo student to maintain 5 nautical miles and 1000 ft between all aircraft throughout the phase of radar vectoring. In this kind of approach aircraft are in sequence depending on altitude, where the nearest aircraft to ILS glide will be the lowest. We except that aircraft in higher altitude has also higher true air speed. Therefore, it is appropriate to gradually increase the value of horizontal separation minimum of one nautical mile for each additional aircraft. This procedure ensures 5 miles of horizontal separations overhead FAP between all aircraft. [5]
The advantage of radar vectoring via single point is that the aircraft can be vectored into the sequence from different directions and APP ATCo can change final approach route depending on requirements for the use of airspace.
Figure 1. Radar vectoring via single point (FAP)
2. VECTORING VIA TWO POINTS FROM TWO SIDES
Radar vectoring via two points from two sides is used in enlarged traffic from more directions especially at airports with two or more parallel runways, but can be used at one runway airports. Figure 2 shows radar vectoring from the left side via Final Approach Point (FAP) and radar vectoring from the right side via mirror placed point, where the mirror axis is the ILS glide path. [6]
Figure 2. Radar vectoring via two points from two sides
Among the aircraft approaching from the same side, it is necessary to maintain a horizontal separation of 10 nautical miles and a vertical separation on 2000 ft to ensure separation of 5 nautical miles and 1000 ft between aircraft in the final approach phase. This kind of radar vectoring can be used with the larger traffic from two or more sides. The main advantages of radar vectoring from two sides include the use of the opposite runway for departures in favorable meteorological conditions. Main disadvantage is that ATCo has to pay attention to more regions. [2][1]
3. VECTORING VIA TWO POINTS FROM THE SAME SIDE
Radar vectoring via two points from one side can be used with the larger traffic from the same. This is a final approach via two parallel routes separated by 5 nautical miles, where the aircraft are in sequence with a horizontal separation of 10 nautical miles and a vertical separation of 2000 ft to ensure a separation of 5 nautical miles and 1000 ft between aircraft in the final approach phase.
Figure 3. Vectoring via two points from the same side
The disadvantage of radar vectoring via two points from the same side is that during radar vectoring with cross winds, ATCo may have problems with maintaining all aircraft on specified route. However, the main advantage is that APP ATCo has ¾ of airspace clear, which can be used for departures or VFR traffic. In this way, ATCo needs to pay attention to only ¼ of the airspace. [7]
4. ENSURING SEPARATIONS BY DIVERTING AIRCRAFT FROM PREVIOUSLY ASSIGNED ROUTE
During radar vectoring of aircraft to the final approach, whether from one direction or from several directions, the horizontal separation can be reduced to less than 5 nautical miles. In this case, the best opinion seems to be to divert aircraft from previously assigned. When the horizontal separation is increased to more than 5 nautical miles, aircraft is vectored back to the primary route. This maneuver is shown in Figure 4.
The advantage of this maneuver is that ATCo may divert aircraft from a previously assigned route for an arbitrary amount of time, which can provide any amount of horizontal separation depending on aircraft altitude and ground speed. [1]
Figure 4. Separations by diverting aircraft
5. SEPARATION REDUCTION WITH RADAR VECTORING CLOSE TO ROUTE
During radar vectoring aircraft to final approach, whether from one or several directions, horizontal separation may be increased to more than 5 nautical miles. Such a situation solves Figure 5, when ATCo gives a heading to the aircraft, which approaches the aircraft closer to FAP or to previously assigned route. This will ensure the reduction of horizontal separation to the desired value. [4]
The advantage of this maneuver is that ATCo need only one instruction to complete the maneuver and very easily ensure continuity and economics of air traffic flow management.
Figure 5. Separation reduction
6. ENSURING SEPARATIONS BY 360° TURN
If the horizontal separation between two aircraft during radar vectoring to final approach is less than 3 nautical miles, it is appropriate to use the maneuver called 360° turn. Aircraft is introduced to spin a full 360° turn to the left or right, depending on the final approach direction and on other traffic in APP ATCo operation zone.
Figure 6. 360° Turn
In standard heeling angle of 25°, or when the angular speed is 3 ms-1, the length of a standard turn by 360° will take 120 seconds, which is sufficient to increase the horizontal spacing to the desired 5 nautical miles. The advantage of the 360° turn is that the ATCo needs only one instruction to separate targets. In air traffic management, this maneuver is considered uneconomic and uncomfortable because it reduces the comfort of the passengers who are exposed to the uncomfortable heeling angle of 25° for full 2 minutes. [7]
7. SEPARATIONS DURING EMERGENCY SITUATION
If during radar vectoring one of the aircraft request priority landing due to an emergency situation, ATCo has to vector this target through a route as short as possible to FAP. This maneuver is shown in Figure 7.
Aircraft with the emergency situation has absolute priority over all aircraft in the operation area. Aircraft which are in sequence behind the target with the emergency situation will continue through an unchanged route, and aircraft which are in front of emergency situation will continue to the end of the approach pattern. This maneuver ensures minimum delay for all flights. [3]
Figure 7. Emergency situation and priority landing
CONCLUSION
The article describes the basic methods of radar vectoring the aircraft at airports with one runway. The article points how to vector aircraft to airports with one runway via single or via two final approach fix during different situations and different traffic density. This methods of radar vectoring should help air traffic controllers during the training phase to improve safety and economics in air traffic. One of the methods gives instruction how to ensure separation minimum between aircraft during emergency situation in zone of responsibility of air traffic controller situated in approach control services.
REFERENCES
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