7. AIRCRAFT

7. Aircraft
   1. Introduction
   2. Wake Turbulence
   1. Separation due to vortex
   2. Waiving wake turbulence Separation
   3. Aircraft Approach Category
   4. Aircraft classification
   5. Equipment suffix
   6. Figure F7.1 - Aircraft performance table
   7. Figure F7.2 - Equipment suffix table

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7.1 Introduction [S]

All aircraft don't have the same performance. Weight, weather and winds can make the same airplane have different performance on different flights.
As a controller, you should have knowledge about the performance of aircraft under normal circumstances in order to be able to plan traffic flow and give the pilots relevant instructions.
At the end of this section, you will find a table which lists the performance of the most usual aircrafts. Use this table as reference.

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7.2 Wake Turbulence [S]

All aircraft generate turbulence called vortex wake. Large aircraft flying at slow speeds create the most severe wake turbulence. This turbulence can cause problems for following aircraft, which in severe cases can cause the pilot of the following aircraft to loose control. In addition to separation minimum above, the following spacing minima therefore needs to be taken into account. The wake turbulence categories are based on the certified maximum take-off weight (MTOW) of the aircraft.
 

AIRCRAFT CATEGORY	MTOW
Light Aircraft (L)	7 000 kg
Medium Aircraft (M)	7 000 – 136 000 kg
Heavy Aircraft (H)	>136 000 kg

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       7.2.1 Separation due to vortex [C]

This leads to the following minimum separation that needs to be maintained at all times on Arrival.
 

LEADING AIRCRAFT	FOLLOWING AIRCRAFT	SEPERATION IN NM
Heavy	Heavy	4
Heavy	Medium	5
Heavy	Light	6
Medium	Light	5

Vortex separation is required when a lighter aircraft follows a heavier.
No vortex separation is required between aircraft of same category, except between heavies.
If parallel runways are being used and they are closer to each other than 760 meters, then they should be considered as one single runway so far as wake turbulence is concerned.
Any aircraft performing a Touch and Go or a Stop and Go is considered a departing aircraft on the climb out phase.

For departing aircraft, 2 minutes separation (3 minutes if the succeeding aircraft departs from an intersection) is applied when an aircraft in wake turbulence category LIGHT or MEDIUM departs behind an aircraft in wake turbulence category HEAVY, or when a LIGHT category aircraft departs behind a MEDIUM category aircraft.
 
Any Helicopter under your control must be kept clear of any light aircraft due to the Rotor Down-wash it produces when hovering and the vortices it produces in forward flight.

If you have a heavy and a light aircraft both ready for departure, you should clear the light aircraft for take-off first in order to avoid wake delay. However this only applies if it does not create any undue delay to the heavy aircraft. If this is the case, then the rule applies in that the faster aircraft is released first.

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       7.2.2 Waiving wake turbulence Separation [C+]

You may issue a take-off clearance to an aircraft that has waived wake turbulence separation, except, if it's a light or medium aircraft departing as follows:

• Behind a heavy a/c and takeoff is started from an interception or along the runway in the direction of take-off.
• Behind a heavy a/c that is taking off or making a low or missed approach in the opposite direction on the same runway.
• Behind a heavy a/c that is making a low or missed approach in the same direction of the runway.

7.3 Aircraft Approach Category [C]

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7.4 Aircraft classification [C]

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7.5 Equipment suffix [C]

These suffixes denote what navigation and transponder equipment is available for the aircraft, as filed in the flight plan by the pilot.
Be alert as to the equipment available on the aircraft and issue vectors accordingly.
A list over the most common codes for equipment can be found at the end of this section.

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Figure F7.1 - Aircraft performance table [Ref]