Now it’s time to let them fly, but before we do, we must first consider the following:
· Is the flight plan correct as described in the taxi checklist?
· Will we need to apply wake turbulence separation from the preceding?
· Do we need to provide additional spacing from the preceding departure?
· Does the required separation exist to depart the aircraft prior to another aircrafts arrival?
· If the aircraft is VFR and requires coordination, are there any special restrictions from the radar controller?
· Issue the takeoff clearance.
· Issue the Rolling Boundary Notification.
· Initiate the handoff.
Let’s examine these in detail:
Is the flight plan correct? As this is the last chance to correct anything before the aircraft becomes airborne, you want to make sure that everything is in order. If the tower controller is also working the ground role, this really isn’t a factor as you have completed your taxi checklist prior to the taxi. However if you have a ground controller working, you must check these items, as it’s the towers responsibility to have a complete strip prior to departure.
Wake turbulence separation: As the wake turbulence separation minima is covered in detail in chapter 3 section 9 of the 7110.65, make sure you're aware of the aircraft types of both the departing and preceding aircraft to determine if this applies.
Provide additional separation? You must consider the preceding departures aircraft type (and speed) relative to the departures type, to determine if additional time or the use of diverging heading techniques should be employed. For example if you have a C152 departing ahead of a B737, you would want to consider turning the Cessna early to avoid the flight path of the Boeing, otherwise the Boeing (and all departures behind) would be caused unnecessary delays while waiting for the Cessna to get enough “head-start” to maintain separation.
Do we have adequate separation from landing aircraft? As new tower students tend to focus too close to the airport, conflicts can occur when you have a fast moving arrival just out of your field of view, so it’s very important to know who’s flying in your airspace at all times. When you have a stream of arrivals as well as a line up of departures, the trick is to thread them to allow the most efficient flow of traffic without compromising separation minimums, wake turbulence, and safety. You must also consider that the landing aircraft can call a missed approach, or go around for whatever reason. Make sure you don’t roll an aircraft until you're sure there’s no conflict.
VFR Coordination: For all turbojet, turboprop and fast piston aircraft (faster than 190 knots), and any aircraft requesting flight following, you must coordinate with radar. This is done in the same manner as a rolling boundary notification, except you want to give radar a bit more information. For example,
LAX_TWR: “LAX_APP, N123X CE500 VFR SOUTH, AOA 50 25R”
LAX_APP: “HDG 230 AOA 70”
In this example, you're telling (coordinating with) radar you have a Citation N123X VFR heading to the south, at or above 5000’. Radar wants the aircraft to depart heading 230 and to maintain VFR at or above 7000’. This must be part of the takeoff clearance.
Issue the Takeoff clearance: At this point, all that’s left is to issue any last minute instructions from radar, the winds and runway, for example, “AAL123 winds 290 at 12, runway 25R cleared for takeoff”. It’s a very common error for the tower student to read these out of order, such as “cleared for takeoff 25R”. Remember the last instruction should be “cleared for takeoff” except in special circumstances, explained below.
For VFR departures not requiring coordination, you need to tell them how to depart the ATA Airport Traffic Area: Normally a 5 mile radius around the airport, from the surface to 2500' AGL Above Ground Level. with the takeoff clearance. Because of noise abatement and to avoid northbound aircraft from flying into SMO airspace, in normal operations we restrict their turn at the shoreline. For example:
“Cessna 35X make left crosswind departure at the shoreline, winds 250 at 10, runway 25R, cleared for takeoff”.
The class bravo clearance and altitude restrictions are omitted in this clearance because they were already given in the initial call, however you can include them again if you wish, especially if you have a ground controller working.
“Cessna 35X cleared out of the bravo airspace to the south, maintain VFR at or below 5000 while in the bravo, make left crosswind departure at the shoreline, winds 250 at 10, runway 25R, cleared for takeoff”.
VFR departures requiring coordination are cleared the same way as a regular VFR, except you need to coordinate with radar before you issue the takeoff clearance, and read any amended instructions from radar. For example, a Learjet who filed VFR to the south would have been given the initial clearance from ground or delivery,
“Learjet 5CL cleared out of the bravo airspace to the south, maintain VFR at or above 5000, departure frequency 125.8, squawk 1008”
As the aircraft approaches the runway, you would call radar with the request:
LAX_TWR: “LAX_APP, N5CL L45 VFR SOUTH AOB 5000 5R”
LAX_APP: “H210 AOA 7000 APPROVED”
As the radar controller wants the aircraft to fly heading 210 at or above 7000, your takeoff clearance would read:
“Learjet 5CL after departure fly heading 210, maintain VFR at or above 7000, winds 250 at 8, runway 25R cleared for takeoff”
When you have a stream of arrivals and departures waiting, here are a couple tricks to keep traffic flowing smoothly and safely.
“Position and Hold” (POH): As your arrivals normally are assigned the outer runways, you can save precious time by issuing this instruction to your departure aircraft. POH instructs the aircraft to line up on the active runway and be ready to takeoff at any moment. When issuing a POH, you should always tell the aircraft the reason, i.e. “UAL421 runway 25R position and hold, traffic 2 mile final for the parallel”, or “AAL21 runway 25R position and hold, traffic, a B737 crossing runway 25R”. NOTE: You cannot tell an aircraft to POH from an intersection at night.
“Depart without delay”: This instruction is given with the takeoff clearance if it’s apparent the aircraft is just taking their sweet time about things. “Cessna 123X, winds 290 at 12 runway 25R depart without delay, traffic a Boeing 737 5 mile final”. Just like the POH, when you issue this you should tell the aircraft the reason, and is used when you want to expedite the aircraft movement, but there’s no immediate danger of having a separation conflict.
“Cleared for immediate takeoff”: This instruction should only be given when the aircraft has been given a previous takeoff clearance, and has failed to start their takeoff run in a timely manner when separation issues with an arriving aircraft become a potential factor. Again the reason should also be stated, “Piper 45G, runway 25L, cleared for immediate takeoff, traffic a B767 heavy 2 mile final 25L”. Although in real life, as tower controllers will use this as a primary takeoff clearance when things get tight, avoid this phrase due to bad planning, or trying to rush the pilots, as in VATSIM, you will end up with a deal in your hands.
“Cancel takeoff clearance”: This implies exactly what is sounds like, and without further instructions, means to hold their present position and not move until further clearance is received. In this case you always want to advise the aircraft as to what they should do, such as “hold position”, “taxi back”, or “taxi clear of the runway”. The reasons for this instruction are optional to the aircraft, as this is “urgent” instruction is something the aircraft must do at once.
Issue the rolling boundary notification: At LAX a rolling boundary notification is exactly the same as an IFR release, except you don’t need approval from the radar controller to issue the takeoff clearance, and no response is required from the radar controller. The text format is abbreviated like a scratch, with the call sign, DP, transition, and departing runway, for example:
“UAL1610 LX5 DAG 5R”
“CAL2110 NRV TRM 4L”
Initiate the handoff: “Contact Socal departure 124.15” or “change to advisory frequency approved”. This is the last transmission to have the aircraft to switch to the radar controllers frequency or to UNICOM. This should be transmitted as soon as the aircraft becomes airborne. This also when you verify that their transponder is on squawking mode Charlie.
In tower mode for ASRC or VRC, the “+” symbol in the data-tag indicates their squawking standby” which the approach or center controller cannot see. The “*” symbol shows the transponder is on. As this is the MOST overlooked item on the pilots’ checklist, you must insure they have their transponder on when you ship them. Usually a friendly reminder is, “check transponder on squawking mode Charlie”.