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16.41 Indication of Heavy Category. Because of the inherent problems caused by heavy wake turbulence category aircraft requiring additional separation, pilots of heavy category aircraft are to indicate the aircraft’s heavy category in the initial RTF contact with an ATCU by the inclusion of the suffix “heavy” to the identifying call sign of the aircraft. e.g. “London

Control this is Speedbird 216 heavy on 133.650”

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Radar Wake Turbulence Separation

16.42 Radar Wake Turbulence Separation. Because the position of the aircraft is displayed to the controller, the required separation for wake turbulence in this case is expressed in distance. The table below contains the wake turbulence radar separation minima specified by ICAO which will be applied to aircraft in the approach and departure phases of flight. Note that in this case the criteria apply where the category of the following aircraft is lighter than the leading aircraft, except for the heavy/heavy case.

Aircraft Wake Turbulence Category
Leading Aircraft	Following Aircraft	Separation
Heavy	Heavy	4 NM
Heavy	Medium	5 NM
Heavy	Light	6 NM
Medium	Light	5 NM

Figure 16.20 Radar wake turbulence separation criteria

Visual Separation in the Vicinity of Aerodromes

16.43 Introduction. Except in conditions where ‘Low Visibility’ operations are in progress at an aerodrome, traffic flying in the vicinity of the aerodrome including arriving, departing and local area traffic, will be flying in conditions which will either permit VFR or pilots of aircraft to maintain separation from other aircraft visually. The importance of this cannot be overstressed as the application of visual separation not only relieves the ATCO of having to impose either procedural or radar separation, but permits minimum runway occupancy time, ‘land after’ procedures and multiple aircraft flying in the visual traffic pattern. In effect, the application of visual separation increases aerodrome capacity and hence aerodrome utilization. Typically, Heathrow has the capacity to accommodate about 60 take-off operations and 60 landing operations per hour and at peak time the traffic load gets close to this. If procedural or radar separation had to be applied to the arrival or departure phases of operations, the utilization would reduce dramatically. The standards previously mentioned can be reduced if:

•Adequate separation can be provided by the aerodrome controller when each aircraft is continuously visible to the controller; or

•Flight crews report that they have visual contact with other aircraft and this can be maintained; or

•In the case of one aircraft following another, the crew of the following aircraft report that the leading aircraft is within sight and that separation can be maintained.

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16.44Essential Local Traffic. Any aircraft, vehicle or personnel on or near the runway, or traffic in the take-off and climb out areas or the final approach area, which may constitute a collision hazard to a departing or arriving aircraft is defined as essential local traffic. Where essential local traffic is known to the controller the information is to be transmitted to flight crews without delay.

16.45Departing Aircraft. Under IFR, departing aircraft will normally be separated from each other by requiring the aircraft to follow a SID. ATCUs will co-ordinate the issuing of clearances, and where possible, standard clearances will be used. Such clearances will normally be specified by the approach controller and passed to the aircraft by the aerodrome control tower. For departures in VMC, the aerodrome controller will clear an aircraft for take-off once the preceding aircraft has either:

•Passed the upwind end of the runway, or

•Has made a turn away from the runway.

Where wake turbulence separation is applied, departures will be sequenced to minimize delays and maximize runway utilization. For IFR traffic, the standard separation between departures is 5 minutes (12 movements per hour). This may be reduced to 2 minutes between aircraft following the same departure track providing the preceding aircraft has filed a FP speed 40 kt greater than the succeeding aircraft. This may further be reduced to 1 minute (60 movements per hour) providing the track of the succeeding aircraft diverges from that of the preceding aircraft by 45° or more. Obviously, where parallel runways are used for simultaneous take-offs, or diverging runways are used, higher utilization rates (lower separation) may be achieved.

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Figure 16.21

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16.46Departure Sequence. At busy aerodromes, the ground movement of aircraft will be planned to ensure that the stated Off Blocks Time can be translated into the necessary slot time for the aircraft. This is the job of the Ground Movements Planner working for the aerodrome controller. If correctly sequenced, the aircraft will arrive at the holding point (or holding area) in the correct order for take-off. Consideration will also be given to the route of the aircraft immediately after take-off to minimize wake turbulence separation. Departure may be expedited by suggesting a take-off direction that is not into wind. In this case, the PIC is to make the decision if this is acceptable.

16.47Delays. It is inevitable that at some point a delay will occur. In which case, flights may be cleared to take off in an order based on the estimated departure time. Deviation from this may be made to facilitate the maximum number of departures with the least average delay, or in response to requests from operators. ATCUs should inform operators when anticipated delays exceed 30 minutes.

16.48Arriving Aircraft. Arriving IFR aircraft may be cleared to make a visual approach provided that:

•The pilot can maintain visual reference to terrain; and

•The reported ceiling is at or above the approved initial approach level; or

•The pilot reports that at any time during an instrument approach the meteorological conditions are such that there is a reasonable assurance that an approach and landing will be made visually.

16.49 Separation. ATC will provide separation between aircraft making a visual approach and all other arriving or departing traffic. For arriving IFR traffic (in IMC) the Approach Controller will transfer control of the aircraft to the Aerodrome Controller at a point during the approach so that separation from departing traffic can be achieved and sufficient time is available to issue a landing clearance. For certain types of approach (PAR or SRA) the aircraft will remain under control of the Approach Radar Controller throughout the approach. This will necessitate the radar controller obtaining the landing clearance and passing it to the pilot during the latter stages of the approach. The Aerodrome Controller in co-operation with the Approach Controller will be responsible for sequencing departures during low visibility IFR operations. Two situations are considered:

•Complete Approach. If an aircraft is making a complete instrument approach, a departing aircraft may take off in any direction until an arriving aircraft has started its procedure turn or base turn leading to final approach OR in a direction which is different by at least 45 degrees from the reciprocal of the direction of approach after the arriving aircraft has started a 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 16.22)

•Straight-in Approach. If an aircraft is making a straight-in approach, a departing aircraft may take off in any direction until 5 minutes before the arriving aircraft is estimated to be over the instrument runway OR in a direction which is different by at least 45 degrees from the reciprocal of the direction of approach of the arriving aircraft until 3 minutes before the arriving aircraft is estimated to be over the beginning of the instrument runway OR before the arriving aircraft crosses a designated fix on the approach track as determined by the ATS authority. (see Figure 16.22)

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Figure 16.22

	16.50 Information to Arriving Aircraft. If a pilot requests it, or it is apparent to ATC that the
	pilot of an aircraft is not familiar with the procedures for an instrument approach, information
	will be passed to enable the approach to be flown. If the aircraft has been cleared for a		16
	straight-in approach, only details of the final approach track need be passed.
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	case) are in progress, a missed approach to the landing runway creates a simultaneous
	16.51 Missed Approach Tracks. Where parallel runway segregated operations (the Heathrow
	departure situation where procedures for Mode 3 are not in force. To overcome the problems
	this creates, procedures are to be implemented to ensure that the missed approach track
	diverges from the normal departure track by at least 30°.

Figure 16.23

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