Manual of Air Traffic Services-Part 1 PDF

Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5 SEPARATION METHODS AND MINIMA 5.1 PROVISION FOR THE SEPARATION OF CONTROLLED TRAFFIC 5.1.1 General 5.1.1.1...

Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5 SEPARATION METHODS AND MINIMA 5.1 PROVISION FOR THE SEPARATION OF CONTROLLED TRAFFIC 5.1.1 General 5.1.1.1 Vertical or horizontal separation shall be provided: a) between IFR flights in class C, D and E airspaces except when VMC climb or descent is involved under the conditions specified in Para 5.4.5; b) between IFR flights and VFR flights in class C airspace; c) between IFR flights and special VFR flights; and d) between special VFR flights. Note: Class A and B are not designated in India. 5.1.1.2 No clearance shall be given to execute any manoeuvre that would reduce the spacing between two aircraft to less than the separation minimum applicable in the circumstances. 5.1.1.3 Larger separations than the specified minima should be applied whenever exceptional circumstances such as unlawful interference or navigational difficulties call for extra precautions. This should be done with due regard to all relevant factors so as to avoid impeding the flow of air traffic by the application of excessive separations. Note: Unlawful interference with an aircraft constitutes a case of exceptional circumstances, which might require the application of separations larger than the specified minima, between the aircraft being subjected to unlawful interference and other aircraft. 5.1.1.4 Where the type of separation or minimum used to separate two aircraft cannot be maintained, another type of separation or another minimum shall be established prior to the time when the current separation minimum would be infringed. 5.1.2 Degraded Aircraft Performance 5.1.2.1 Whenever, as a result of failure or degradation of navigation, communications, altimetry, flight control or other systems, aircraft performance is degraded below the level required for the airspace in which it is operating, the flight crew shall advise the ATC unit concerned without delay. Where the failure or degradation affects the separation minimum currently being employed, the controller shall take action to establish another appropriate type of separation or separation minimum. January 4, 2024 ED/ATM/2024/E6.2-MATS-PRT1 P a g e | 5-1 Manual of Air Traffic Services-Part 1 Airports Authority of India CHAPTER 5: SEPARATION METHODS AND MINIMA 5.2 LOSS OF SEPARATION 5.2.1 If, for any reason, a controller is faced with a situation in which two or more aircraft are separated by less than the prescribed minima due to reason other than ACAS RA (e.g. air traffic control errors or difference in the pilot’s estimated and actual times over reporting points) controller is to a) use every means at his disposal to obtain the required minimum with the least possible delay; and b) pass essential traffic information. 5.3 ESSENTIAL TRAFFIC INFORMATION 5.3.1 Essential traffic is that controlled traffic to which the provision of separation by ATC is applicable, but which, in relation to a particular controlled flight is not, or will not be, separated from other controlled traffic by the appropriate separation minimum. 5.3.2 Essential traffic information shall be given to controlled flights concerned whenever they constitute essential traffic to each other. 5.3.3 Essential traffic information shall include: a) direction of flight of aircraft concerned; b) type and wake turbulence category (if relevant) of aircraft concerned; c) cruising level of aircraft concerned and; 1) estimated time over the reporting point nearest to where the level will be crossed; or 2) relative bearing of the aircraft concerned in terms of the 12-hour clock as well as distance from the conflicting traffic; or 3) actual or estimated position of the aircraft concerned. 5.4 VERTICAL SEPARATION 5.4.1 Vertical Separation Minimum a) A nominal 1000 ft below FL290 and a nominal 2000 ft at or above FL290, except as provided for in b) below; and b) A nominal 1000 ft when both aircraft are RVSM compliant and operating within designated RVSM airspace. 5.4.2 Assignment of Cruising Levels for Controlled Flights Note: Cruise climb is not permitted in Indian FIRs 5.4.2.1 If it is necessary to change the cruising level of an aircraft operating along an established ATS route extending partly within and partly outside controlled airspace and where the respective series of cruising levels are not identical, the change shall, whenever possible, be effected within controlled airspace. 5.4.2.2 When an aircraft has been cleared into a control area at a cruising level which is below the established minimum cruising level for a subsequent portion of the route, the ATC unit responsible for the area should issue a P a g e | 5-2 ED/ATM/2024/E6.2-MATS-PRT1 January 4, 2024 Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5: SEPARATION METHODS AND MINIMA revised clearance to the aircraft even though the pilot has not requested the necessary cruising level change. 5.4.2.3 An aircraft may be cleared to change cruising level at a specified time, place or rate. 5.4.2.4 In so far as practicable, cruising levels of aircraft flying to the same destination shall be assigned in a manner that will be correct for an approach sequence at destination. 5.4.2.5 An aircraft at a cruising level shall normally have priority over other aircraft requesting that cruising level. When two or more aircraft are at the same cruising level, the preceding aircraft shall normally have priority. 5.4.2.6 The cruising levels to be assigned to controlled flights shall be selected from those allocated to IFR flights in: a) the tables of cruising levels in Appendix 3 of Annex 2; or b) a modified table of cruising levels, when so prescribed in accordance with Appendix 3 of Annex 2 for flights above FL410; except that the correlation of levels to track as prescribed therein shall not apply whenever otherwise indicated in air traffic control clearances or specified by the appropriate ATS authority in AIP. 5.4.3 Vertical Separation During Climb and Descent 5.4.3.1 An aircraft may be cleared to a level previously occupied by another aircraft after the latter has reported vacating it, except when: a) severe turbulence is known to exist; or b) the aircraft concerned are entering or established at the same holding pattern; or c) the difference in aircraft performance is such that less than the applicable separation minimum may result; in which case such clearance shall be withheld until the aircraft vacating the level has reported at or passing another level separated by the required minimum. 5.4.3.2 Pilot in direct communication with each other may, with their concurrence, be cleared to maintain a specified vertical separation between their aircraft during ascent or descent. 5.4.4 Step Climb and Descents 5.4.4.1 The step climb/descent procedure may be used for simultaneous climb/descent of the aircraft to vertically separated levels provided that the lower/higher aircraft is progressively assigned levels that provide vertical separation with the higher/lower aircraft. 5.4.4.2 When applying the step climb or step descent procedures, pilot must be advised that they are subject to a step climb or descent. January 4, 2024 ED/ATM/2024/E6.2-MATS-PRT1 P a g e | 5-3 Manual of Air Traffic Services-Part 1 Airports Authority of India CHAPTER 5: SEPARATION METHODS AND MINIMA 5.4.5 VMC Climb and Descent 5.4.5.1 When so requested by an aircraft and provided it is agreed by the pilot of the other aircraft, an ATC unit may clear a controlled flight, including departing and arriving flights, operating in airspace classes D and E in VMC during the hours of daylight to fly subject to maintaining own separation to one other aircraft and remaining in VMC. When a controlled flight is so cleared, the following shall apply: a) clearances shall be for a specified portion of the flight at or below 10,000 ft, during climb and descent; b) essential traffic information shall be passed; and c) if there is possibility that flight under VMC may become impracticable, an IFR flight shall be provided with alternative instructions to be complied with in the event that in VMC cannot be maintained for the term of clearance. 5.5 HORIZONTAL SEPARATION 5.5.1 Lateral Separation 5.5.1.1 Lateral Separation Application 5.5.1.1.1 Lateral separation of aircraft is obtained by requiring operation on different routes or in different geographical locations as determined by visual observation, by the use of navigation aids or by the use of area navigation (RNAV) equipment. 5.5.1.1.2 When information is received indicating navigation equipment failure or deterioration below the navigation performance requirements, ATC shall then, as required, apply alternative separation methods or minima. 5.5.1.1.3 Where a route flown by an aircraft involves a specified turn which will result in the minimum lateral separation being infringed, another type of separation or another minimum shall be established prior to the aircraft commencing the turn (see Figures 5-1 and 5-2). Note 1: For fly-over waypoints aircraft are required to first fly over the waypoint before executing the turn. After the turn the aircraft may either navigate to join the route immediately after the turn or navigate to the next defined waypoint before re-joining the route. This will require additional lateral separation on the overflown side of the turn (see Figure 5-1 (b)). Note 2: An aircraft may commence a fly-by turn up to 20 NM prior to the turn waypoint, and fly a path displaced from that waypoint by as much as 9 NM. The defined radius for the fixed radius transition (FRT) turn dictates how early the aircraft starts the turn and the displacement from the waypoint. Fly-by and FRT turns, therefore, have the possibility of affecting a restricted area or another route on the inside of the turn. For instrument flight procedures, the Radius arc to a Fix (RF) path terminator will provide consistent turn performance (see Figures 5-1 and 5-2). Further details on this issue can be found in the Manual on the Use of Performance-based Navigation (PBN) in Airspace Design (Doc 9992). P a g e | 5-4 ED/ATM/2024/E6.2-MATS-PRT1 January 4, 2024 Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5: SEPARATION METHODS AND MINIMA Fly-by turns An aircraft will calculate a turn radius and angle of bank (AOB) subject to performance characteristics, airspeed, altitude, angle of turn and wind conditions. The aircraft determine to initiate the turn, prior to the waypoint, based on the calculated radius — this may be up to 20 NM before the waypoint. There will be a variation in the paths because each aircraft calculates its own turn radius (indicated by the grey area in the figure within which the flight path of the aircraft will be located). This variation becomes more apparent at higher altitudes and greater turn angles. The controller can expect the aircraft track to be on the inside of the waypoint. Figure 5-1(a): Turn at fly-by waypoint and turn over fly-over waypoint (see Para 5.5.1.1.3) January 4, 2024 ED/ATM/2024/E6.2-MATS-PRT1 P a g e | 5-5 Manual of Air Traffic Services-Part 1 Airports Authority of India CHAPTER 5: SEPARATION METHODS AND MINIMA Fly-over turn An aircraft will come to the overhead of the waypoint before initiating the turn onto the next leg. Therefore, if the minimum prescribed lateral separation is applied, it will be infringed upon as the aircraft manoeuvres onto its next leg. The controller can expect the aircraft track to be on the outside of the waypoint. Figure 5-1 (b): Turn at fly-by waypoint and turn over fly-over waypoint (see Para 5.5.1.1.3) P a g e | 5-6 ED/ATM/2024/E6.2-MATS-PRT1 January 4, 2024 Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5: SEPARATION METHODS AND MINIMA Fixed radius transition (FRT) An FRT for published en-route RNP ATS routes has a turn radius specified by the airspace planner. Approaching the waypoint, the FMC/FMS will calculate the arc centre and will initiate the turn at a point at which the flight path is perpendicular to the radius which links the point to the calculated centre. This turn type should provide highly consistent and repeatable turn performance. Figure 5-2 (a): Fixed radius transition (FRT) and radius arc to a fix (RF) turn (see Para 5.5.1.1.3) January 4, 2024 ED/ATM/2024/E6.2-MATS-PRT1 P a g e | 5-7 Manual of Air Traffic Services-Part 1 Airports Authority of India CHAPTER 5: SEPARATION METHODS AND MINIMA Radius arc to a fix (RF) The RF for Instruments Flight Procedures (IFP) is a curved route segment that has been designed with a published radius and arc centre. Aircraft will initiate the turn at the waypoint defining the start of the curved segment and will follow the published route until the next waypoint. This turn type should provide highly consistent and repeatable turn performance Figure 5-2 (b): Fixed radius transition (FRT) and radius arc to a fix (RF) turn (see Para 5.5.1.1.3) P a g e | 5-8 ED/ATM/2024/E6.2-MATS-PRT1 January 4, 2024 Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5: SEPARATION METHODS AND MINIMA 5.5.1.2 Lateral Separation Criteria and Minima 5.5.1.2.1 Means by which lateral separation may be applied include the following: 5.5.1.2.1.1 By reference to the same or different geographic locations: By position reports which positively indicate the aircraft are over different geographic locations as determined visually or by reference to a navigation aid (see Figure 5-3). Figure 5-3: Using same or different geographic locations (See Para 5.5.1.2.1.1) 5.5.1.2.1.2 By use of NDB, VOR or GNSS on intersecting tracks or ATS routes: By requiring aircraft to fly on specified tracks which are separated by a minimum amount appropriate to the navigation aid employed. Lateral separation between two aircraft exists when: a) VOR: both aircraft are established on radials diverging by at least 15 degrees and at least one aircraft is 15* NM or more from the facility (see Figure 5-4); *When distance from VOR is based on co-located DME, distance of one aircraft should be at least 17 NM from VOR below FL190 and 18 NM from VOR at or above FL190. Figure 5-4: Separation using the same VOR [See Para 5.5.1.2.1.2 a)] b) NDB: both aircraft are established on tracks to or from the NDB, which are diverging by at least 30 degrees and at least one aircraft is 15 NM or more from the facility (see Figure 5-5); January 4, 2024 ED/ATM/2024/E6.2-MATS-PRT1 P a g e | 5-9 Manual of Air Traffic Services-Part 1 Airports Authority of India CHAPTER 5: SEPARATION METHODS AND MINIMA Figure 5-5: Separation using the same NDB [See Para 5.5.1.2.1.2 b)] c) GNSS/GNSS: each aircraft is confirmed to be established on a track with zero offset between two waypoints and at least one aircraft is at a minimum distance from a common point as specified in Table 5-1; or d) VOR/GNSS: the aircraft using VOR is established on a radial to or from the VOR and the other aircraft using GNSS is confirmed to be established on a track with zero offset between two waypoints and at least one aircraft is at a minimum distance from a common point as specified in Table 5-1. Angular difference Aircraft 1: VOR or GNSS between tracks Aircraft 2: GNSS measured at the common point Limits of level Below At or above FL190 to FL190 to FL010 FL460 Distance from a 15o-135o 15 NM 23 NM common point When DME is being utilized to provide 17 NM 25 NM range information Table 5-1: Lateral separation for aircraft flying VOR and GNSS [See Paras 5.5.1.2.1.2 c) and d)] 5.5.1.2.1.2.1 Before applying GNSS-based track separation, the controller shall confirm the following: a) ensure that the aircraft is navigating using GNSS; and b) in airspace where strategic lateral offsets are authorized, that a lateral offset is not being applied. 5.5.1.2.1.2.2 In order to minimize the possibility of operational errors, waypoints contained in the navigation database or uplinked to the aircraft flight management system should be used in lieu of manually entered waypoints, when applying GNSS-based track separation. In the event that it is operationally restrictive to use waypoints contained in the navigation database, the use of waypoints that require manual entry by pilots should be limited to a half or whole degree of latitude and longitude. P a g e | 5-10 ED/ATM/2024/E6.2-MATS-PRT1 January 4, 2024 Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5: SEPARATION METHODS AND MINIMA 5.5.1.2.1.2.3 GNSS-based track separation shall not be applied in cases of pilot-reported receiver autonomous integrity monitoring (RAIM) outages. Note: For the purpose of applying GNSS-based lateral separation minima, distance and track information derived from an integrated navigation system incorporating GNSS input is regarded as equivalent to GNSS distance and track. 5.5.1.2.1.2.4 GNSS receivers used for applying separation shall meet the requirements in Annex 10, Volume I, and be indicated in the flight plan. 5.5.1.2.1.3 By using crossing radials of the same VOR: When one aircraft is maintaining a radial from a VOR and other aircraft is crossing its track at an angular difference of 45 degrees to 135 degrees inclusive, aircraft will be deemed to be laterally separated, when the other aircraft: a) has passed the radial of first aircraft; and b) crossed a radial which is different by at least 20 degrees from the radial of first aircraft; and c) is 20 DME or more from the VOR used by first aircraft. Note: See Figure 5-6 Figure 5-6: Separation by using crossing radial of same VOR (see Para 5.5.1.2.1.3) January 4, 2024 ED/ATM/2024/E6.2-MATS-PRT1 P a g e | 5-11 Manual of Air Traffic Services-Part 1 Airports Authority of India CHAPTER 5: SEPARATION METHODS AND MINIMA 5.5.1.2.1.4 Lateral separation of aircraft on published instrument flight procedures for arrivals and departures 5.5.1.2.1.4.1 Lateral separation of departing and/or arriving aircraft, using instrument flight procedures, will exist: a) where the distance between any combination of RNAV 1 with RNAV 1, or RNP 1, RNP APCH or RNP AR APCH tracks is not less than 7 NM; or b) where the distance between any combination of RNP 1, RNP APCH or RNP AR APCH tracks is not less than 5 NM; or c) where the protected areas of tracks designed using obstacle clearance criteria do not overlap and provided operational error is considered. 5.5.1.2.1.5 RNAV operations where RNP is specified on parallel tracks or ATS routes 5.5.1.2.1.5.1 Within designated airspace or on designated routes, where RNP is specified, lateral separation between RNAV equipped aircraft may be obtained by requiring aircraft to be established on the centre line of parallel tracks or ATS routes spaced at a distance which ensures that the protected airspace of the tracks or ATS routes do not overlap. P a g e | 5-12 ED/ATM/2024/E6.2-MATS-PRT1 January 4, 2024 Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5: SEPARATION METHODS AND MINIMA 5.5.1.2.1.6 Lateral separation of aircraft on parallel or non-intersecting tracks or ATS routes 5.5.1.2.1.6.1 Within designated airspace or on designated routes, lateral separation between aircraft operating on parallel or non-intersecting tracks or ATS routes shall be established in accordance with Table 5-2: Minimum spacing between Performance requirements tracks Airspace where Airspace Additional SLOP is not where requirements authorized, or is SLOP up to Navigation Communication Surveillance only authorized 2 NM is up to 0.5 NM authorized Types of RNAV 10 communication (RNP 10) 50 NM 50 NM other than direct RNP 4 controller-pilot RNP 2 VHF voice Conformance monitoring shall be ensured by establishing an ADS-C event RNP 4 contract specifying 20 NM 23 NM RCP 240 RSP 180 RNP 2 a lateral deviation change event with a maximum of 5 NM threshold and a waypoint change event While one aircraft Types of climbs/descends RNP 2 or communication through the level of 20 NM 23 NM GNSS other than direct another aircraft equipage* controller-pilot remaining in level VHF voice flight RNP 2 or Direct N/A 15 NM GNSS controller-pilot equipage* VHF voice While one aircraft climbs/descends N/A RNP 4 through the level of 9 NM RCP 240 RSP 180 RNP 2 another aircraft remaining in level flight While one aircraft climbs/descends RNP 2 or Direct N/A through the level of 7 NM GNSS controller-pilot another aircraft equipage* VHF voice remaining in level flight *See PANS-ATM, DOC 4444, Appendix 2, ITEM 10: EQUIPMENT AND CAPABILITIES, in relation to the GNSS equipage. Table 5-2: Lateral separation of aircraft on parallel or non-intersecting tracks or ATS routes January 4, 2024 ED/ATM/2024/E6.2-MATS-PRT1 P a g e | 5-13 Manual of Air Traffic Services-Part 1 Airports Authority of India CHAPTER 5: SEPARATION METHODS AND MINIMA 5.5.1.2.1.6.2 When the minima in Para 5.5.1.2.1.6.1 are applied by requiring one or both aircraft to establish a specified lateral offset, vertical separation shall be maintained by the controller until the manoeuvring aircraft is established on the applicable lateral offset. 5.5.1.2.1.7 Lateral Separation of Aircraft on Intersecting Tracks or ATS Routes 5.5.1.2.1.7.1 Lateral separation between aircraft operating on intersecting tracks or ATS routes shall be established in accordance with the following: a) an aircraft converging with the track of another aircraft is laterally separated until it reaches a lateral separation point that is located a specified distance measured perpendicularly from the track of the other aircraft (see Figure 5-7); and b) an aircraft diverging from the track of another aircraft is laterally separated after passing a lateral separation point that is located a specified distance measured perpendicularly from the track of the other aircraft (see Figure 5- 7). This type of separation may be used for tracks that intersect at any angles using the values for lateral separation points specified in Table 5-3: Navigation Separation RNAV 10 (RNP 10) 50 NM RNP 4 23 NM RNP 2 15 NM Table 5-3: Lateral separation of aircraft on intersecting tracks or routes (see Para 5.5.1.2.1.7.1) Figure 5-7: Lateral separation points (see Para 5.5.1.2.1.7.1) P a g e | 5-14 ED/ATM/2024/E6.2-MATS-PRT1 January 4, 2024 Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5: SEPARATION METHODS AND MINIMA 5.5.1.2.1.7.2 When applying the 15 NM separation minima specified in the Table 5-3, a GNSS, as indicated in the flight plan by the letter G meets the specified navigation performance. 5.5.2 Longitudinal Separation 5.5.2.1 For the purpose of application of longitudinal separation, the terms same track, reciprocal tracks and crossing tracks shall have the following meaning: a) Same track: same direction tracks and intersecting tracks or portions thereof, the angular difference of which is less than 45 degrees or more than 315 degrees, and whose protected airspaces overlap (see Figure 5.8 (a)). b) Reciprocal tracks: Opposite tracks and intersecting tracks or portions thereof, the angular difference of which is more than 135 degrees but less than 225 degrees, and whose protected airspaces overlap (see Figure 5.8 (b)). c) Crossing tracks: Intersecting tracks or portions thereof other than those specified in a) and b) above (see Figure 5.8 (c)) Figure 5-8: Aircraft on (a) same track, (b) reciprocal tracks and (c) crossing tracks (see Para 5.5.2.1) January 4, 2024 ED/ATM/2024/E6.2-MATS-PRT1 P a g e | 5-15 Manual of Air Traffic Services-Part 1 Airports Authority of India CHAPTER 5: SEPARATION METHODS AND MINIMA 5.5.2.2 Longitudinal Separation Minima Based on Time 5.5.2.2.1 Cross-Check Calculations a) Separation requirements must be cross-checked to ensure the integrity of calculations. b) The cross-check is to validate the initial calculation and to confirm that the calculation is consistent with the traffic disposition. 5.5.2.2.2 Aircraft Maintaining the Same Level 5.5.2.2.2.1 Aircraft on the same track: a) 15 minutes (see Figure 5-9); or Figure 5-9: 15 minutes separation between aircraft on same track and same level b) 10 minutes, if navigation aids permit frequent determination of position and speed (see Figure 5-10). Figure 5-10: 10 minutes separation between aircraft on same track and same level P a g e | 5-16 ED/ATM/2024/E6.2-MATS-PRT1 January 4, 2024 Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5: SEPARATION METHODS AND MINIMA 5.5.2.2.2.2 Aircraft flying on crossing tracks: a) 15 minutes (see figure 5-11); or Figure 5-11: 15 minutes separation between aircraft on crossing track and same level b) 10 minutes, if navigation aids permit frequent determination of position and speed (see Figure 5-12). Figure 5-12: 10 minutes separation between aircraft on crossing track and same level 5.5.2.2.3 Aircraft Climbing or Descending 5.5.2.2.3.1 Aircraft on the same track: When an aircraft will pass through the level of another aircraft on the same track, the following minimum longitudinal separation shall be provided: a) 15 minutes, while vertical separation does not exist (see Figure 5-13) (a) January 4, 2024 ED/ATM/2024/E6.2-MATS-PRT1 P a g e | 5-17 Manual of Air Traffic Services-Part 1 Airports Authority of India CHAPTER 5: SEPARATION METHODS AND MINIMA (b) Figure 5-13: 15 minutes separation between aircraft (a) climbing, (b) descending on same track (see Para 5.5.2.2.3.1 a)) b) 10 minutes, while vertical separation does not exist, provided that such separation is authorized only where navigation aids permit frequent determination of position and speed (see Figure 5-14) (a) (b) Figure 5-14: 10 minutes separation between aircraft (a) climbing, (b) descending on same track (see Para 5.5.2.2.3.1 b)). P a g e | 5-18 ED/ATM/2024/E6.2-MATS-PRT1 January 4, 2024 Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5: SEPARATION METHODS AND MINIMA Note: To facilitate application of the procedure where a considerable change of level is involved, a descending aircraft may be cleared to some convenient level above the lower aircraft, or a climbing aircraft to some convenient level below the higher aircraft, to permit a further check on the separation that will obtain while vertical separation does not exist. c) 5 minutes, while vertical separation does not exist, provided that: i. the level change is commenced within 10 minutes of the time the second aircraft has reported over a common point which must be derived from ground-based navigation aids or by GNSS (see Figure 5-15); and ii. when issuing the clearance through third party communication or CPDLC, a restriction shall be added to the clearance to ensure that the 10 minute condition is satisfied. (a) (b) Figure 5-15: 5 minutes separation between aircraft (a) climbing, (b) descending and on same track (see Para 5.5.2.2.3.1 c)) January 4, 2024 ED/ATM/2024/E6.2-MATS-PRT1 P a g e | 5-19 Manual of Air Traffic Services-Part 1 Airports Authority of India CHAPTER 5: SEPARATION METHODS AND MINIMA 5.5.2.2.3.2 Aircraft on crossing tracks: a) 15 minutes, while vertical separation does not exist (see Figure 5-16); (a) (b) Figure 5-16: 15 minutes separation between aircraft (a) climbing, (b) descending on crossing tracks (see Para 5.5.2.2.3.2 a)). b) 10 minutes, while vertical separation does not exist if navigation aids permit frequent determination of position and speed (see Figure 5-17). (a) P a g e | 5-20 ED/ATM/2024/E6.2-MATS-PRT1 January 4, 2024 Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5: SEPARATION METHODS AND MINIMA (b) Figure 5-17: 10 minutes separation between aircraft (a) climbing, (b) descending on crossing tracks (see Para 5.5.2.2.3.2 b)). 5.5.2.2.3.3 Aircraft on reciprocal tracks: Where lateral separation is not provided, vertical separation shall be provided for at least 10 minutes prior to and after the time the aircraft are estimated to pass, or are estimated to have passed. Provided that it has been determined that the aircraft have passed each other, this minimum need not apply (see Figure 5-18). Figure 5-18:10 minutes separation between aircraft climbing/ descending on reciprocal tracks (see Para 5.5.2.2.3.3) 5.5.2.3 Longitudinal separation minima based on distance using Distance Measuring Equipment (DME) and/or GNSS Note: Where the term “on-track” is used in the provisions relating to the application of longitudinal separation minima using DME and/or GNSS, it means that the aircraft is flying either directly inbound to or directly outbound from the station/waypoint. 5.5.2.3.1 Separation shall be established by maintaining not less than specified distance(s) between aircraft positions as reported by reference to DME in conjunction with other appropriate navigation aids and/or GNSS. This type of separation shall be applied between two aircraft using DME, or two aircraft using GNSS, or one aircraft using DME and one aircraft using January 4, 2024 ED/ATM/2024/E6.2-MATS-PRT1 P a g e | 5-21 Manual of Air Traffic Services-Part 1 Airports Authority of India CHAPTER 5: SEPARATION METHODS AND MINIMA GNSS. Direct controller-pilot VHF voice communication shall be maintained while such separation is used. Note: For the purpose of applying GNSS-based separation minimum, a distance derived from an integrated navigation system incorporating GNSS input is regarded as equivalent to GNSS distance. 5.5.2.3.2 All distance reports must be made with reference to the same DME station and/or collocated waypoint and/or same waypoint. 5.5.2.3.3 When applying these separation minima between any aircraft with area navigation capability, controllers shall specifically request GNSS derived distance. Note: Reasons making a pilot unable to provide GNSS distance information may include inadequate onboard equipment, no GNSS input into an integrated navigation system, or a loss of GNSS integrity. 5.5.2.3.4 Aircraft at the same cruising level 5.5.2.3.4.1 Aircraft on the same track: a) 20 NM, provided: 1. each aircraft utilizes, i. the same on-track DME station when both aircraft are utilizing DME, or ii. an on-track DME station and a collocated waypoint when one aircraft is utilizing DME and the other is utilizing GNSS, or iii. the same waypoint when both aircraft are utilizing GNSS, and 2. separation is checked by obtaining simultaneous DME and/or GNSS readings from the aircraft at frequent intervals to ensure that the minimum will not be infringed (see Figure 5-19). Figure 5-19: 20 NM DME and/or GNSS-based separation between aircraft on same track same level (see Para 5.5.2.3.4.1 a)) P a g e | 5-22 ED/ATM/2024/E6.2-MATS-PRT1 January 4, 2024 Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5: SEPARATION METHODS AND MINIMA b) 10 NM, provided: 1. the leading aircraft maintains a true airspeed of 20 kts or more faster than the succeeding aircraft; 2. each aircraft utilizes, i. the same on-track DME station when both aircraft are utilizing DME, or ii. an on-track DME station and a collocated waypoint when one aircraft is utilizing DME and the other is utilizing GNSS, or iii. the same waypoint when both aircraft are utilizing GNSS, and 3. separation is checked by obtaining simultaneous DME and/or GNSS readings from the aircraft at frequent intervals to ensure that the minimum will not be infringed (see Figure 5-20). Figure 5-20: 10 NM DME and/or GNSS-based separation between aircraft on same track same level (see Para 5.5.2.3.4.1 b)) 5.5.2.3.4.2 Aircraft on crossing tracks: The longitudinal separation prescribed in Para 5.5.2.3.4.1 shall also apply provided each aircraft reports distance from the DME station and/or collocated waypoint or same waypoint located at the crossing point of the tracks and that the relative angle between the tracks is less than 900 (see Figures 5-21 and 5-22). Figure 5-21: 20 NM DME and/or GNSS-based separation between aircraft on crossing track and same level (see Para 5.5.2.3.4.2) January 4, 2024 ED/ATM/2024/E6.2-MATS-PRT1 P a g e | 5-23 Manual of Air Traffic Services-Part 1 Airports Authority of India CHAPTER 5: SEPARATION METHODS AND MINIMA Figure 5-22: 10 NM DME and/or GNSS-based separation between aircraft on crossing track and same level (See Para 5.5.2.3.4.2) 5.5.2.3.5 Aircraft climbing or descending 5.5.2.3.5.1 Aircraft on the same track:10 NM, while vertical separation does not exist, provided: a) each aircraft utilizes: i. the same on-track DME station when both aircraft are utilizing DME, or ii. an on-track DME station and a collocated waypoint when one aircraft is utilizing DME and the other is utilizing GNSS, or iii. the same waypoint when both aircraft are utilizing GNSS; and b) one aircraft maintains a level while vertical separation does not exist; and c) separation is established by obtaining simultaneous DME and/or GNSS readings from the aircraft (see Figure 5-23). Note: To facilitate application of the procedure where a considerable change of level is involved, a descending aircraft may be cleared to some convenient level above the lower aircraft, or a climbing aircraft to some convenient level below the higher aircraft, to permit a further check on the separation that will obtain while vertical separation does not exist. P a g e | 5-24 ED/ATM/2024/E6.2-MATS-PRT1 January 4, 2024 Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5: SEPARATION METHODS AND MINIMA (a) (b) Figure 5-23: 10 NM DME and/or GNSS-based separation between aircraft (a) climbing, (b) descending on same track (see Para 5.5.2.3.5.1) 5.5.2.3.5.2 Aircraft on reciprocal tracks: Aircraft utilizing on-track DME and/or collocated waypoint or same waypoint may be cleared to climb or descend to or through the levels occupied by other aircraft utilizing on-track DME and/or collocated waypoint or same waypoint, provided that it has been positively established that the aircraft have passed each other and are at least 10 NM apart. 5.5.2.4 Longitudinal separation minima with Mach number technique based on time: 5.5.2.4.1 Aircraft subject to Mach number technique shall adhere to the Mach number approved by ATC and shall request ATC approval before making any changes thereto. If it is essential to make an immediate temporary change in the Mach number (e.g. due to turbulence), ATC shall be notified as soon as possible that such a change has been made. 5.5.2.4.2 If it is not feasible, due to aircraft performance, to maintain the last assigned Mach number during en-route climbs and descents, pilots of aircraft concerned shall advise ATC at the time of the climb/descent request. January 4, 2024 ED/ATM/2024/E6.2-MATS-PRT1 P a g e | 5-25 Manual of Air Traffic Services-Part 1 Airports Authority of India CHAPTER 5: SEPARATION METHODS AND MINIMA 5.5.2.4.3 When the Mach number technique is applied and provided that: a) The aircraft concerned have reported over the same common point and follow the same track or continuously diverging tracks until some other form of separation is provided; or b) If the aircraft have not reported over the same reporting point and it is possible to ensure, by radar, by ADS-B or by other means, that the appropriate time interval will exist at the common point from which they either follow the same track or continuously diverging tracks; minimum longitudinal separation between aircraft on the same track, whether in level, climbing or descending flight shall be: 1) 10 minutes; or 2) between 9 and 5 minutes inclusive, provided that, the preceding aircraft is maintaining a true Mach number greater than the following aircraft in accordance with the following:  9 minutes, if the preceding aircraft is Mach 0.02 faster than the following aircraft;  8 minutes, if the preceding aircraft is Mach 0.03 faster than the following aircraft;  7 minutes, if the preceding aircraft is Mach 0.04 faster than the following aircraft;  6 minutes, if the preceding aircraft is Mach 0.05 faster than the following aircraft;  5 minutes, if the preceding aircraft is Mach 0.06 faster than the following aircraft. 5.5.2.4.4 When the 10-minute longitudinal separation minimum with Mach number technique is applied, the preceding aircraft shall maintain a true Mach number equal to or greater than that maintained by the following aircraft. 5.5.2.4.5 If after establishing the Mach number technique between aircraft, control information indicates that less than the applicable minima between aircraft may exist, immediately alternate form of separation must be ensured. Note: Application of differential Mach number shall be applied only when LOA between two ATC centres permits. 5.5.2.5 Longitudinal separation minima based on distance using RNAV where RNP is specified 5.5.2.5.1 Separation shall be established by maintaining not less than the specified distance between aircraft positions, as reported by reference to the same “on-track” common point, whenever possible ahead of both aircraft, or by means of an automated position reporting system. Note: The term “on-track” means that the aircraft is flying either directly inbound to or directly outbound from the station or waypoint. P a g e | 5-26 ED/ATM/2024/E6.2-MATS-PRT1 January 4, 2024 Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5: SEPARATION METHODS AND MINIMA 5.5.2.5.1.1 When information is received indicating navigation equipment failure or deterioration below the navigation performance requirements, ATC shall then, as required, apply alternative separation minima. 5.5.2.5.1.2 Direct controller-pilot communications shall be maintained while applying a distance-based separation minima. Direct controller-pilot communications shall be voice or CPDLC. 5.5.2.5.1.3 When aircraft are at, or are expected to reduce to, the minimum separation applicable, speed control techniques, including assigning Mach number, shall be applied to ensure that the minimum distance exists throughout the period of application of the minima. 5.5.2.5.2 Longitudinal distance-based separation minima in an RNP/RNAV environment not using ADS-C 5.5.2.5.2.1 For aircraft cruising, climbing or descending on the same track, the separation minimum in Table 5-5 may be used: Separation RNP Communication Surveillance Distance minimum type requirement requirement verification requirements. 50 NM 10 Direct controller- Procedural At least every 24 pilot position reports minutes communications Table 5-5: Longitudinal separation minima in an RNP/RNAV environment not using ADS-C; for aircraft cruising, climbing or descending on the same track. Note: Where a considerable change of level is involved using distance- based separation, a descending aircraft may be cleared to some convenient level above the lower aircraft, or a climbing aircraft to some convenient level below the higher aircraft (e.g. 4000 ft or less) to permit a further check on the separation that will be maintained while vertical separation does not exist. 5.5.2.5.2.2 During the application of the 50 NM separation, when an aircraft fails to report its position, the controller shall take action within 3 minutes to establish communication. If communication has not been established within 8 minutes of the time the report should have been received, the controller shall take action to apply an alternative form of separation. 5.5.2.5.2.3 Aircraft on reciprocal tracks: Aircraft may be cleared to climb or descend to or through the levels occupied by the other provided that it has been positively established that the aircraft have passed each other and the distance between them is equal to at least the applicable separation minimum. January 4, 2024 ED/ATM/2024/E6.2-MATS-PRT1 P a g e | 5-27 Manual of Air Traffic Services-Part 1 Airports Authority of India CHAPTER 5: SEPARATION METHODS AND MINIMA 5.6 SEPARATION OF AIRCRAFT HOLDING IN FLIGHT 5.6.1 Except when lateral separation as specified in MATS-Part 2, exists, aircraft established in adjacent holding patterns shall be separated by the applicable vertical separation minimum. 5.6.2 Except when lateral separation exists, vertical separation shall be applied between aircraft holding in flight and other aircraft, whether arriving, departing or en- route, whenever the other aircraft concerned are within 5 minutes flying time of the holding area (see Figure 5-24). Figure 5-24: Separation between holding aircraft and en-route aircraft 5.7 MINIMUM SEPARATION BETWEEN DEPARTING AIRCRAFT 5.7.1 1-minute separation, if aircraft are to fly on tracks diverging by at least 450 immediately after take-off so that lateral separation is provided (see Figure 5-25). Figure 5-25: 1-minute separation between departing aircraft following tracks diverging by at least 45 degrees (see Para 5.7.1) Note: Wake turbulence categorization of aircraft and longitudinal separation minima are contained in Para 5.9. 5.7.2 2-minutes between take-offs when the preceding aircraft is 40 kts or more faster than the following aircraft and both aircraft propose to follow the same track (see Figure 5-26). P a g e | 5-28 ED/ATM/2024/E6.2-MATS-PRT1 January 4, 2024 Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5: SEPARATION METHODS AND MINIMA Note: Calculations, based on TAS, of speed differentials of aircraft during climb may not be sufficiently accurate in all circumstances for determining if the procedures in Para 5.7.2 can be applied, in which case calculations based on IAS may be more suitable. Figure 5-26: 2-minute separation between aircraft following same track (see Para 5.7.2) 5.7.3 5-minute separation, while vertical separation does not exist if a departing aircraft will be flown through the level of a preceding departing aircraft and both aircraft propose to follow the same track. Action must be taken to ensure that the 5-minute separation will be maintained or increased while vertical separation does not exist (see Figure 5-27). Figure 5-27: 5-minutes separation of departing aircraft following same track (see Para 5.7.3) January 4, 2024 ED/ATM/2024/E6.2-MATS-PRT1 P a g e | 5-29 Manual of Air Traffic Services-Part 1 Airports Authority of India CHAPTER 5: SEPARATION METHODS AND MINIMA 5.8 SEPARATION OF DEPARTING AIRCRAFT FROM ARRIVING AIRCRAFT 5.8.1 The following separation shall be applied when take-off clearance is based on the position of an arriving aircraft: 5.8.1.1 If an arriving aircraft is making a complete instrument approach, a departing aircraft may take off: a) in any direction until an arriving aircraft has started its procedure turn or base turn leading to final approach; b) in a direction which is different by at least 450 from the reciprocal of the direction of approach after the arriving aircraft has started procedure turn or base turn leading to final approach, provided that the take-off will be made at least 3 minutes before the arriving aircraft is estimated to be over the beginning of the instrument runway (see Figure 5-28). 5.8.1.2 If an arriving aircraft is making a straight-in approach, a departing aircraft may take off: a) in any direction until 5 minutes before the arriving aircraft is estimated to be over the instrument runway; b) in a direction which is different by at least 450 from the reciprocal of the direction of approach of the arriving aircraft: i. until 3 minutes before the arriving aircraft is estimated to be over the beginning of the instrument runway (see Figure 5-28), or ii. before the arriving aircraft crosses a designated fix on the approach track; the location of such fix to be determined after consultation with the operators and published in MATS-Part 2. Note 1: Lateral separation is considered to exist between an arriving aircraft that subsequently commenced final approach and the departing aircraft that has established on a course diverging by at least 450 from the reciprocal of the final approach course. Note 2: Use of runway other than runway-in-use for the purpose of application of separation vide Paras 5.8.1.1 a) and 5.8.1.2 b) is not authorized. P a g e | 5-30 ED/ATM/2024/E6.2-MATS-PRT1 January 4, 2024 Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5: SEPARATION METHODS AND MINIMA Figure 5-28: Separation of departing aircraft from arriving aircraft. 5.8.2 Departing aircraft is maintaining a radial from a VOR and arriving aircraft established on a collocated DME arc: i. Case 1: An arriving aircraft carrying out a DME arc procedure, and a departing aircraft established on a track which is different by at least 450 from the reciprocal of the direction of final approach track of the arriving aircraft, will be deemed to be laterally separated, when a) the arriving aircraft is established on a DME arc of at least 10 NM using same VOR and is moving away from the track of the departing aircraft maintaining VOR radial; and b) the departing aircraft maintaining the VOR radial is crossing the arc of the arriving aircraft from behind; and c) the arriving aircraft has passed a VOR radial which is different by at least 300 from the radial maintained by departing aircraft (see Figure 5-29). January 4, 2024 ED/ATM/2024/E6.2-MATS-PRT1 P a g e | 5-31 Manual of Air Traffic Services-Part 1 Airports Authority of India CHAPTER 5: SEPARATION METHODS AND MINIMA Figure 5-29: Separation between departing and arriving aircraft- Arriving aircraft established on a 10 DME arc and departing aircraft crossing the arc from behind. ii. Case 2: When a departing aircraft is maintaining a radial from a VOR and arriving aircraft established on a DME arc of at least 10 NM using same VOR, will be deemed to be laterally separated, when the aircraft established on VOR radial is at a DME distance of 10 NM or greater than the DME arc maintained by the arriving aircraft (see Figure 5-30). Figure 5-30: Separation between departing and arriving aircraft- Arriving aircraft established on a 10 DME arc and departing aircraft is at least 10 NM away from the arc. P a g e | 5-32 ED/ATM/2024/E6.2-MATS-PRT1 January 4, 2024 Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5: SEPARATION METHODS AND MINIMA 5.9 TIME-BASED WAKE TURBULENCE LONGITUDINAL SEPARATION MINIMA Note— Distance-based wake turbulence separation minima are set forth in Chapter 8, 8.16.4. 5.9.1 Applicability 5.9.1.1 The ATC unit concerned shall not be required to apply wake turbulence separation: a) for arriving VFR flights landing on the same runway as a preceding landing SUPER, HEAVY or MEDIUM aircraft; and b) between arriving IFR flights executing visual approach when the aircraft has reported the preceding aircraft in sight and has been instructed to follow and maintain own separation from that aircraft. 5.9.1.2 The ATC unit shall, in respect of the flights specified in 5.9.1.1 a) and b), as well as when otherwise deemed necessary, issue a caution of possible wake turbulence. The pilot-in-command of the aircraft concerned shall be responsible for ensuring that the spacing from a preceding aircraft of a heavier wake turbulence category is acceptable. If it is determined that additional spacing is required, the flight crew shall inform the ATC unit accordingly, stating their requirements. 5.9.2 Arriving Aircraft 5.9.2.1 Except as provided in 5.9.1.1 (a) and (b), the following minima shall be applied to aircraft landing behind a SUPER, a HEAVY or a MEDIUM aircraft: a) HEAVY aircraft landing behind SUPER aircraft — 2 minutes; b) MEDIUM aircraft landing behind SUPER aircraft — 3 minutes; c) MEDIUM aircraft landing behind HEAVY aircraft — 2 minutes; d) LIGHT aircraft landing behind SUPER aircraft — 4 minutes e) LIGHT aircraft landing behind a HEAVY or MEDIUM aircraft — 3 minutes. 5.9.3 Departing Aircraft 5.9.3.1 When using wake turbulence categories contained in Chapter 4, 4.15.1 and when the aircraft are using: a) the same runway;(see Figure 5-31); b) parallel runways separated by less than 760 m (2500 ft); (see Figure 5-31); January 4, 2024 ED/ATM/2024/E6.2-MATS-PRT1 P a g e | 5-33 Manual of Air Traffic Services-Part 1 Airports Authority of India CHAPTER 5: SEPARATION METHODS AND MINIMA c) crossing runways if the projected flight path of the second aircraft will cross the projected flight path of the first aircraft at the same altitude or less than 1000 ft below; (see Figure 5-32); d) parallel runways separated by 760 m (2500 ft) or more, if the projected flight path of the second aircraft will cross the projected flight path of the first aircraft at the same altitude or less than 1000 ft below (see Figure 5-32); the following minimum separations shall be applied: 1) HEAVY aircraft taking off behind a SUPER aircraft — 2 minutes; 2) LIGHT or MEDIUM aircraft taking off behind a SUPER aircraft — 3 minutes; 3) LIGHT or MEDIUM aircraft taking off behind a HEAVY aircraft — 2 minutes; 4) LIGHT aircraft taking off behind a MEDIUM aircraft — 2 minutes. Figure 5-31: Wake turbulence separation for following aircraft on parallel runway Figure 5-32: Wake turbulence separation for aircraft operating from crossing runway P a g e | 5-34 ED/ATM/2024/E6.2-MATS-PRT1 January 4, 2024 Airports Authority of India Manual of Air Traffic Services-Part 1 CHAPTER 5: SEPARATION METHODS AND MINIMA 5.9.3.2 When using wake turbulence categories contained in Chapter 4, 4.15.1 for aircraft taking off from an intermediate part of the same runway or an intermediate part of a parallel runway separated by less than 760 m (2 500 ft) (see Figure 5-33), the following minimum separations shall be applied: a) HEAVY aircraft taking off behind a SUPER aircraft — 3 minutes; b) LIGHT or MEDIUM aircraft taking off behind a SUPER aircraft — 4 minutes; c) LIGHT or MEDIUM aircraft taking off behind a HEAVY aircraft — 3 minutes; d) LIGHT aircraft taking off behind a MEDIUM aircraft – 3 minutes Figure 5-33: Wake turbulence separation for aircraft operating from intermediate part of runway 5.9.4 Displaced Landing Threshold 5.9.4.1 When using wake turbulence categories contained in Chapter 4, 4.15.1 and when operating a displaced landing threshold, the following minimum separations shall be applied if the projected flight paths are expected to cross: a) a departing HEAVY aircraft following a SUPER aircraft arrival — 2 minutes; b) a departing LIGHT or MEDIUM aircraft following a SUPER aircraft arrival — 3 minutes; c) a departing LIGHT or MEDIUM aircraft following a HEAVY aircraft arrival — 2 minutes; d) a departing LIGHT aircraft following a MEDIUM aircraft arrival — 2 minutes; January 4, 2024 ED/ATM/2024/E6.2-MATS-PRT1 P a g e | 5-35