Tower

Determining the Active Runway

Controllers should determine the active runway based on the following factors:

1. Winds – Choosing the runway with the largest headwind component.
2. Runway length/characteristics – If the headwind component between two runways is similar, choosing the one which is longer, or which has an ILS, etc.
3. Local procedures (e.g., preferred runway for noise abatement, if one exists.)

Flexibility should also be granted where possible. Traffic permitting, one should make all reasonable efforts to accommodate any requests from pilots to use non-active runways.

Control Zone (CTR)

In addition to the runways, TWR is also responsible for the Control Zone (CTR), the airspace immediately surrounding their airport. This includes controlling VFR arrivals, departures, and aircraft in the circuit. See the VFR Guide for more information.

Takeoff Clearances

Takeoff clearance must not be issued unless the runway is free and will remain free (no aircraft may be on the runway, cleared to land, etc.) for the entire duration of the aircraft’s takeoff roll.

The takeoff clearance should include:

• Winds
• Departure runway
• (Intersection departures only) The runway intersection
• (IFR departures only) The next ATS unit which the aircraft will be contacting.
  • This may be omitted if one is covering TWR top-down.

For example:

🎧 ICE214, winds 180 degrees 14 knots, runway 19, cleared for takeoff.

🎧 FNA102, when airborne contact Keflavik Approach on 119.300, winds 170 degrees 12 knots, runway 19 from S, cleared for takeoff.

For VFR departures, the takeoff clearance should include the flight’s VFR clearance to join the circuit, VFR route, or leave the control zone. See the VFR Guide for examples.

Taxiing on the Runway

Any taxiing or backtracking on the runway is to be conducted on the TWR frequency. TWR should transfer the aircraft back to GND once it is clear of the runway.

Departure Separation

Fixed-wing aircraft departing on the same SID must have 5 NM constant or increasing separation in trail. TWR is permitted to use radar to ensure this separation is achieved.

Wake turbulence separation must be applied between departures when the second (trailing) aircraft is a lighter WTC than the first (preceding) aircraft, and they are using:

• The same runway
• Parallel runways separated by less than 760m (2500ft)
• Intersecting 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 300m (1000ft) below
• Parallel runways separated by 760m (2500ft) 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 300m (1000ft) below.

A minimum time separation must be applied as follows:

MINIMUM TIME-BASED SEPARATION FOR DEPARTURES
		First (Preceding) Aircraft
		Light (L)	Medium (M)	Heavy (H)	Super (J)
Second (Trailing) Aircraft	Light (L)	—	2 min	2 min	3 min
	Medium (M)	—	—	2 min	3 min
	Heavy (H)	—	—	—	2 min
	Super (J)	—	—	—	—

One should further add 1 minute to the wake turbulence separation time after any departures from an intermediate point. Touch-and-goes are considered to be departures from an intermediate point. E.g.,

• A Light departure behind a Heavy departure from an intersection requires 3 mins of separation.
• A Medium aircraft behind a Super aircraft doing a touch-and-go requires 4 mins of separation.
  

To maximize efficient use of the runway, if two departures require either wake turbulence or route separation, TWR should utilize the delay time between the two aircraft to allow other aircraft not requiring separation to depart.

Landing Clearances

Landing clearances must not be issued unless the runway is clear, and there is no one ahead on the approach. They must contain the current winds, the arrival runway, and the phrase “cleared to land.” For example:

🎧 ICE403, winds 190 degrees 6 knots, runway 19, cleared to land.

If one previously gave an aircraft the winds & landing runway in a “continue approach” instruction, and neither have changed since then, one does not need to say them again in the landing clearance.

If TWR anticipates that the aircraft will be cleared to land less than 4 NM from the airport, TWR should tell the aircraft to “expect late landing clearance.”

Go-Arounds & Missed Approaches

Go-around may be initiated by the pilot or ATC, if either one feels that the approach cannot be safely continued. TWR should 

IFR go-arounds should generally be instructed to follow the standard (published) missed approach. If an aircraft is not on a published approach (e.g., it is onflying a visual approach),approach, or is unable to follow the standard missed approach, then it may simply be instructed to fly runway heading and climb to a safe altitude (generallyusually 3000ft is appropriate, but higher may be necessary depending on local terrain.)

VFR go-arounds may simply be instructed to (re)join the circuit. This may include making an early turn onto downwind, if necessary to avoid conflicts.

TWR must coordinate all IFR go-arounds with Approach (APP) before transferring the aircraft back to APP! APP may tell TWR to relay immediate instructions to the go-around aircraft, such as a heading or climb/stop climb, in order to avoid conflicts with airborne aircraft.

Maintaining the ATIS

At aerodromes with an ATIS, it is TWR’s responsibility to maintain the ATIS. If TWR is offline, then APP or area control units who are covering TWR top-down shall maintain the ATIS. Only if there are no overlying APP/area control units online should GND or DEL maintain the ATIS.