Updated: 2024-07-30 --- # Positive Vs Procedural Control In order to vector aircraft, controllers must have them under positive control. Positive control relies upon having constant visual or radar contact with the aircraft being controlled. When an aircraft is under positive control, the controller exerts direct control of the aircrafts movements, through vectoring commands. If a controller is unable to maintain positive control or wishes to release an aircraft from positive control, they must place the aircraft under procedural control, which is where an aircraft is given instructions to reach a certain place or follow a certain procedure, and navigates and follows the procedures without controller assistance. Just because a controller is able to maintain positive control does not mean that they are required to or even that it is desirable to do so. Good controllers will move aircraft back and forth between positive and procedural control depending on the situation and phase of flight. # Placing an Aircraft Under Control The first step to placing an aircraft under positive control is for the controller to place that aircraft under their general control. This is usually done by using the prowords “Radar Contact” (for radar control) or “Contact” (for visual control). This is normally done upon an aircraft checking into the frequency. If the controller cannot locate an aircraft visually or on their scope, they use the proword “Negative Contact” to indicate to the aircraft they will be unable to exert positive control and will have to rely on procedural control. > [!example] > `A/C`: “Andersen Approach, Victory 101, on the 050 radial 50, 26 thousand, request” > ==APR==: “Victory 101, Andersen Approach, radar contact, Anderson Altimeter 29.83, landing and departing runway 06 left, final bearing 064, say your request” # Placing an Aircraft Under Positive Control After placing an aircraft under your control, you can place that aircraft under positive control. There is only one way to do this, you have to give a heading instruction to that aircraft. An altitude, speed, or any other instruction does not imply positive control by itself. It is not required to be a turn, even “Maintain Heading” can be used to place an aircraft under positive control. An aircraft under positive control may not change heading or altitude without controller instruction. Aircraft under procedural control may change heading or altitude in order to comply with the procedure. >[!example] `A/C`: “Andersen Approach, Victory 101, altimeter 29.83, request vectors to final for the Tacan Approach runway 06L full stop” ==APR==: “Victory 101 maintain heading, descend and maintain 10,000, you can expect that” # Heading commands There are three basic heading commands, Left, Right, and Maintain. Headings are always spoken with individual digits (120 being “One Two Zero”). Quantity turns are always said as whole numbers (10 degrees being “ten degrees”). Heading turns are preferred over quantity turns whenever practical. “Maintain” is the proword used to instruct an aircraft to keep its current heading. Heading changes are expected to be completed at a minimum of a half standard rate turn. > [!example] Heading Turn > "`[callsign]`,`[Left/Right]` Heading `[heading]`" > > [!quote] > > ==ATC==: “Victory 101, Left Heading one two zero” > [!example] Quantity Turn > "`[callsign]`,`[Left/Right]` `[size of turn]` degrees" > >[!quote] > >==ATC==: “Victory 101, Left ten degrees” >[!example] Maintain >"`[callsign]`, maintain present heading" >or >"`[callsign]`, maintain `[heading]`" > >[!quote] > >==ATC==: “Victory 101 maintain present heading” # Join Command “Join” is a special proword that instructs an aircraft to intercept a particular course and turn on their own to maintain that course. Most commonly this is used to instruct an aircraft to join a particular radial from a navaid or a course from an RNAV flight plan. >[!example] Join >“`[callsign]` join `[course]` `[direction]`” >>[!quote] >>==ATC==: “Victory 101 join the 210 radial outbound” >[!example] > ==ATC==: “Victory 101, right heading 090, join final bearing, cleared for the TACAN approach 06L” # Altitude Commands Altitudes can be read in three formats. The first two reference altitude above mean sea level (MSL), and can be read either in thousands and hundreds (15,500 being “fifteen thousand, five hundred”) or when speaking to military aviators, in Angels (15,500 being “Angels fifteen point five”). The civilian standard is to read the individual digits for thousands (15,500 being "one five thousand, five hundred") The last format references pressure altitude (PA) which implies an altimeter setting of 29.92, when using this format, altitudes are read in individual digits for hundreds of feet and called flight levels (18,500 being “Flight Level one eight five”), in the USA, the flight levels begin at 180 (18,000 ft) For normal altitude changes, a minimum climb/descent rate of 2000ft/min is expected for altitude changes above 5000 ft AGL, and a minimum of 500 ft/min for altitude changes below 5000 ft There are three basic altitude commands, climb, descend, and maintain. Similar to heading calls, there are altitude climbs/descents and quantity climbs/descents. Altitude calls are preferred over quantity calls Altitude climbs/descents are to a specific altitude or block of altitudes, and they include the word maintain. >[!example] Altitude Command >“`[callsign]`, `[Climb/Descend]` and maintain `[altitude]`” >>[!quote] >>==ATC==: “Victory 101, Descend and maintain four thousand” >[!example] Altitude Block > “`[callsign]`, `[Climb/Descend]` and maintain `[altitude]` block `[altitude]`” > >[!quote] > >==ATC==: “Victory 101, Climb and maintain flight level two five zero block two eight zero” Quantity climbs/descents do not use the word maintain and imply a relative change from aircraft current altitude >[!example] Quantity Climb >“`[callsign]`, `[climb/descend]` `[quantity]` feet” >>[!quote] >>==ATC==: “Victory 101, climb one thousand feet” # At or Above/At or Below Aircraft can be ordered to maintain a specific altitude, with a standard of ∓100ft, or they can be given altitude limits by a maintain call. To do this the phrases “At or Above” or “At or Below” can be used. This can be used in the same manner with speed commands. >[!example] Maintain/At or Above/Below >“`[Callsign]`, Maintain `[altitude]`” >>[!quote] >>==ATC==: “Victory 101, Maintain fifteen thousand” > >“`[Callsign]`, Maintain at or `[above/below]` `[altitude]`” >>[!quote] >>==ATC==: “Victory 101, Maintain at or above one thousand five hundred” >[!Example] >==APR==: “Victory 101, right 060, join final bearing, maintain at or above one thousand five hundred until established on the final approach course” # Speed commands Speeds are always read as whole numbers ( 150 kts being “one hundred and fifty”), certain speeds can also be referenced by their names, the most common being “Final Approach Speed” for the speed the aircraft flies when fully configured and on-speed AOA. Knots Indicated is assumed, but knots ground speed can be specified. At or Above/Below can be used with maintain in the same manner as altitude. There are 3 basic speed commands, increase to/reduce to, and maintain. >[!example] Speed >“`[Callsign]` `[increase/reduce]` to `[speed]`” >>[!quote] >>==ATC==: “Victory 101, increase to two hundred” > >“`[Callsign]` maintain `[speed]`” >>[!quote] >>==ATC==: “Victory 101 Maintain one hundred and fifty” >[!Example] ==APR==: “Victory 101 reduce to and maintain at or below two hundred knots until ten DME” # Pilot's Discretion and Resume Own Navigation Pilot's discretion is a way to communicate that previously stated restrictions or normal restrictions do not apply. It can either be communicated by saying something is “pilot’s discretion” or saying to the aircraft “your discretion”. For example after giving a speed command, the usual way to release the aircraft from the command would be to say “101, Speed your discretion”. Pilot’s discretion can be used to allow a non standard climb or descent, for example allowing an aircraft at a low fuel state to stay at high altitude longer with a descent profile greater than the 2000ft/min descent rate. For example “101, Pilot's Discretion descent, Maintain at or below two thousand by ten DME” “Resume Own Navigation” is used to release an aircraft from positive control. It is used either when there is no clearance being issued, or when an aircraft is being told to resume a previous clearance. # When Able, When Stable, Immediate, Expedite, and No Delay Command modifiers from most urgent to least are Immediate>Expedite>No delay> (no modifier)>When able/stable “Immediate” is the most urgent modifier, it is only used for imminent safety of flight situations, it indicates the aircraft should use maximum safe performance. “Expedite” is the next most urgent modifier, it is used when prompt compliance is needed to prevent a situation, aircraft should use maximum safe performance. “No Delay” is a modifier that any delay has the potential to cause danger or disruption, it can be used in both safety of flight and for sequencing purposes. “When able” is used to ‘soften’ a command, it does not remove the responsibility to comply with the command, but it reminds the aircraft to wait until the command can be executed safely, and implies that there is no particular urgency to the command. “When stable” is similar to “when able” but specifically refers to an aircraft in a recovery profile like a bolter or waveoff, and means to execute as soon as recovery is completed >[!Example] Examples > ==ATC==: “Victory 101 immediate left heading 080” > ==ATC==: “Victory 101, right heading 090 when able” > ==ATC==: “Victory 101 expedite climb to eight thousand” # Clearance Clearance is a form of procedural control. A clearance is a instruction and authorization to do something without positive control. A clearance has an associated “clearance limit” which is usually the destination, but can be an intermediate point. An aircraft on a clearance cannot proceed past their clearance limit, they must hold there until receiving further clearance from a controller. An aircraft receiving a clearance with a limit other than their destination, must be given an “expected further clearance” time, which is when they should contact the controller if they have not already received further clearance. When issuing a clearance, it can either be to a specific place or for a particular procedure, like an approach. If clearing an aircraft along a pre-planned route or mission the clearance can simply be “as filed” (route) or “as fragged” (mission) # Cleared to An aircraft can be cleared to a point or a destination, either directly or along a route “Cleared Direct to” implies the aircraft is authorized and required to proceed directly from present position in a straight line to the point mentioned, the “to” can be omitted for brevity >[!example] Cleared to >“`[Callsign]`, Cleared direct (to) `[point]`” >>[!quote] >>==ATC==: “Victory 101, Cleared direct WP1” “Cleared to” “via” implies a particular method of reaching a point >[!example] Via >“`[Callsign]`, cleared (to) `[point]` via `[procedure]`” >>[!quote] >>==ATC==: “Victory 101, cleared to WP1 via the CASE III departure” “Then” implies a further clearance after the stated point, it can be combined with via or direct >[!example] Then >“`[Callsign]`, cleared (to) `[point]` then `[further clearance]`” >>[!quote] >>==ATC==: “Victory 101, cleared to WP1 then as fragged” # Cleared For Cleared for is used to authorize an aircraft to conduct a specific procedure, most commonly an approach. It implies a release from positive control for the duration of the procedure, with the expectation that positive control will be reasserted by the controller at the end of the procedure. An aircraft cleared for a procedure can make any heading, altitude, and speed changes needed to safely comply with the procedure. >[!Example] Cleared For >“`[Callsign]`, cleared for the `[procedure]`” >>[!quote] >>==ATC==: “Victory 101, cleared for the TACAN W approach runway six left” # Report “Report” is a command that instructs the aircraft to tell the controller when something happens. Aircraft reports can include but are not limited to: reaching a position, an altitude or upon sighting something. >[!example] Common usage includes >“Report airfield in Sight” >“Report `[location]`” >“Report traffic in sight” >“Report established in holding” >“Report a `[number]` mile final” >“Report clear of `[airspace name]`” # Contact/Push/Kick/Switch “Contact”, “[[APPENDIX A - ALSSA BREVITY LIST#PUSH [channel]|PUSH]]”, “[[APPENDIX A - ALSSA BREVITY LIST#KICK [appropriate frequency]|KICK]]” and “[[APPENDIX A - ALSSA BREVITY LIST#SWITCH [item]|SWITCH]]” are all words indicating a frequency change. Frequencies are spoken with individual digits, and military controllers do not omit digits or decimals on the radio. Channel numbers are spoken as whole numbers. Contact is generally used when a specific controller or entity is to be met on the new frequency. >[!example] Contact >“`[Callsign]`, Contact `[entity]` on `[channel/frequency]`” >>[!quote] >>==ATC==: “Victory 101, contact tower on one two eight point five” Push and Kick are synonymous, and simply mean to change frequencies to the specified one. >[!example] Push/Kick >"`[Callsign]`, `[Push/Kick]` `[channel/frequency]`” >>[!quote] >>==ATC==: “Victory 101, push channel fifteen” Switch can be used in the same way as push or kick, but implies the change was planned. It can also be used without a specified frequency to indicate that aircraft no longer needs to speak with the controller. This format is shown below >[!example] Switch >“`[Callsign]`, Cleared to Switch” >>[!quote] >>==ATC==: “Victory 101, cleared to switch” # POGO, Monitor [[APPENDIX A - ALSSA BREVITY LIST#[freq] POGO [freq]|POGO]] is a proword meaning “switch to the frequency preceding POGO, if unable to establish contact, go to the frequency after POGO” If no frequency is given after POGO, return to the current frequency instead >[!example] POGO >“`[callsign]` `[contact/push]` `[intended frequency]` POGO `[second frequency]` >>[!quote] >>==ATC==: “Victory 101, push 128.0 POGO 128.5” >>>(check 128.0, if no one there, go to 128.5) >> >>==ATC==: “Victory 101, contact Wizard 264.0 POGO Darkstar 264.1” >>>(if unable to reach wizard on 264.0, contact darkstar on 264.1) >> >>==ATC==: “Victory 101, Push 306.0 POGO” >>>(if no one on 306.0, come back to me on the frequency we are talking on) Monitor means to tune a different radio to the given frequency without switching off this one.