Air Defender glossary: radar, QRA, EW and track terms

Air-to-air refuelling: passing fuel between aircraft while they are flying.

Air-to-air refuelling area: an area marked for aircraft to meet and take fuel while flying.

An established route through the air, shown on the map to help you understand where traffic is expected.

Radio waves travelling differently from the usual atmospheric model, for example bending more strongly towards the ground.

A specialist who works with aircraft weapons.

The game’s message and command window. Use it to read reports, check responses to orders and type supported commands.

Anti-submarine warfare: finding and countering submarines. In aircraft descriptions, this names a military role.

Air traffic control: the service that manages aircraft traffic. In Air Defender, asking ATC can help you check a flight’s information.

A signal getting weaker as it travels. For radar, this can make a returning echo harder to detect.

Airborne Warning and Control System: an aircraft carrying radar and control equipment. In this game, the E-3D Sentry provides the airborne radar picture.

Horizontal direction around a point, measured as an angle. For a radar looking around the horizon, it describes which direction the contact lies.

In Air Defender terminology, a confirmed enemy aircraft. The report identifies the contact; it is not, by itself, your command to fire.

The direction from one position towards another, normally expressed in degrees. In the game’s north-up map, 090 degrees points east; the starting position matters.

A line showing the direction towards a detected signal. One line does not tell you how far away the source is.

In Air Defender, an urgent low-fuel warning. Do not assume there is enough fuel to get home. Check fuel and the current task in ACTIVE OPS, then find the aircraft on the radar scope. Follow the refuelling or return-to-base steps.

An aircraft whose identity has not yet been established as friendly or hostile. Unknown does not automatically mean enemy.

Civil Aviation Authority. This name is used in several countries. NZ CAA means New Zealand’s authority; UK CAA means the United Kingdom’s. Check which country the source names.

The name or letters and numbers used to refer to a flight in communications. Match it with the displayed aircraft before issuing an order.

The name you chose for your player profile. Select that name to use its saved progress and training records. Here, it is your player name, not the name of a flight you are controlling.

Combat air patrol: fighters flying in an assigned area so they are available to respond, instead of waiting on the ground.

One unit in the game’s simplified cargo limit. Different supplies use different numbers of slots. This is not a real aircraft weight limit.

A helicopter approval category for multi-engine designs with specified engine-isolation and take-off/landing requirements after an engine failure. The approved procedures, available space and performance limits still matter.

A helicopter approval category without assured continued flight after an engine failure. An unplanned landing is assumed. It can include helicopters with more than one engine.

An official process for checking that something meets the rules that apply to it. Aircraft design approval and approval of an individual aircraft are different checks.

Unwanted returns on the radar display, such as weather or ground reflections when you are trying to find aircraft.

Advice and feedback about your handling of the game. Find these messages with the YOU filter in ASMA; reading one does not give an aircraft an order.

Something detected or being followed on the display. You may still need to establish what it is.

The small menu opened by right-clicking an object. Its choices depend on what you clicked.

A speed used for the main travelling part of a flight. A reference cruise speed is different from a track’s current speed.

Distress and Diversion: specialists who help aircraft in difficulty. In Air Defender, check the aircraft’s actual code and the D&D monitoring note. A position marker or assignment message alone does not confirm monitoring.

Change an aircraft’s intended landing airfield. For example, send it to a different suitable airfield instead of its original destination.

Danger areas: marked areas where activities may be hazardous to aircraft. This label shows an area, not proof that a dangerous activity is happening at that moment.

The aircraft supplying fuel to another aircraft. In a refuelling operation, the supplying tanker is the donor.

The angle above or below a level direction. Radar elevation measurements can help work out a contact’s height.

Equipment sending out an electronic signal, such as a radar or radio. Listening sensors try to work out where that signal is coming from.

How long an aircraft can remain airborne with the fuel it has. Its speed and what it is doing affect that time.

The fighter’s attack task. Select the fighter, choose ENGAGE and then select the target. An accepted task is not proof that a weapon has already fired.

On the way to the next place. It does not mean that the aircraft or its cargo has arrived.

Estimated time of arrival: a prediction of when something will reach its destination, rather than a guarantee.

Electronic warfare: using or responding to electromagnetic signals, such as radio and radar. In these guides, separate listening for signals from jamming them.

Federal Aviation Administration: the United States aviation authority.

A track that is no longer receiving fresh reports. It flashes to attract attention and can disappear if updates do not resume; that alone does not mean the aircraft was destroyed.

A unit of length used here for aircraft height. Read the display’s scale: a trackblock height of 350 means 35,000 feet, not 350 feet.

In Air Defender terminology, a radio phrase for preparing radar and weapon systems for combat. Use the aircraft’s task and weapons controls.

In Air Defender terminology, a radio phrase for returning radar and weapon systems to a safe or standby state. Check the aircraft’s task and weapons controls.

A flight made to move an aircraft from one location to another.

Flight information region: an area where designated services provide flight information and alerting. A boundary on the map is not a wall that stops aircraft.

A level based on a common standard pressure reference. Its number is in hundreds of feet: FL150 is a standard-pressure altimeter reading of 15,000 feet, not guaranteed height above the ground.

Information about an intended flight, such as its route and destination. Compare that plan with what the aircraft is actually doing.

Computers process the pilot’s or autopilot’s commands and send electrical signals to equipment that moves the aircraft’s control surfaces. This is a flight-control system, not a radar-reporting system.

A report that a semi-active radar-guided missile has been launched. Skyflash is an example: it relies on radar energy reflected from the target.

A report that an active radar-guided missile has been launched. AMRAAM is an example. Check the selected aircraft’s available weapons before assigning an engagement.

A report that an infrared-guided missile has been launched. Sidewinder is an example: it follows infrared energy from the target.

Frames per second: how many pictures the game draws each second. A lower rate can make movement look less smooth.

An aircraft configured to carry goods. The type’s cargo role does not reveal the load of one flight or make it a supply aircraft you can control.

Preparing an aircraft on the ground for another flight. The game attempts to replace a fighter’s fuel and weapons from the base’s supplies.

This can mean kept on the ground because of a restriction, or simply not flying. Read the context: AIRFRAME U/S specifically warns that the aircraft is temporarily unusable.

A summary to help you take over a session: what is happening, which aircraft and resources are available, and what needs attention. Check it against the live picture.

A numbering system using digits 0–9 and letters A–F. Copy all six characters of the displayed Mode S address, including starting zeros.

Keep a contact in your working group after selecting another one. You can have several hooked contacts but only one current selection.

Heads-up display: information shown over the main game view. Here, Toggle Game Status HUD shows or hides the session-status banner.

A display setting that shows only the identity categories you have included. Filtering what you see is different from changing a contact’s identity.

Instrument flight rules: rules for flying using instruments and the relevant procedures. IFR does not mean the flight must be in cloud.

Sending an aircraft to meet another aircraft, for example to find out what it is. An intercept does not automatically mean attacking it.

A fighter used to meet and investigate or, when authorised, engage another aircraft.

Between continents, such as a journey between Europe and North America. A type’s usual long-distance role is not proof of this flight’s destination.

Deliberate radio interference intended to make another system harder to use. Listening for a signal and jamming a signal are different activities.

In Air Defender, an early fuel warning: start arranging refuelling or a return to land. Watch the fuel reading rather than waiting for warnings in a particular order.

A report that the fighter is taking control of the intercept. It is not visual identification or permission to fire. In AC Control, the JUDY button requests the communication exchange; it does not order an attack.

The key assigned to an action. A default binding is the original choice; you can have different keys configured.

A unit of speed used in aviation: nautical miles per hour.

The wheels, skids or floats and their supporting structure used when an aircraft lands. Fixed gear stays outside the aircraft; retractable gear can fold away. A tricycle layout has nose gear at the front and main gear behind it.

Fighters sent out together in one launch. An order given through one fighter can also affect other members of this group.

The line from a contact that shows its direction of movement. Read the speed value for an exact number rather than measuring the line.

Exchanging information with another controller or organisation. In the game, an ASMA liaison conversation lets you ask a controller about a track.

An unobstructed path between two positions. Terrain and Earth’s curvature can hide a low aircraft from a radar; atmospheric bending also affects the radio path.

A radio data link that shares information between systems. Air Defender uses it to bring the E-3D’s radar information into your picture; its control is labelled L11.

The weapons and equipment carried for a mission.

Planning and moving the people and supplies needed for a job, such as keeping aircraft operating.

Searching and observing areas of sea. Maritime means connected with the sea. Check the full aircraft type: the Nimrod MR2 maritime role differs from the R1 signals-intelligence role.

A distress call: an aircraft is threatened by serious or imminent danger and needs immediate assistance. Read the emergency details rather than assuming every distress call has the same cause.

The fighter and target have reached the close visual part of an intercept. They need not occupy the same point on the map. The report does not confirm a collision or a weapon hit.

The compatible military Mode 3 and civilian Mode A system for replying with a four-digit transponder code. The code itself is not a height.

A transponder reply mode that reports pressure altitude, separately from the four-digit identity code.

A passenger aircraft with one main aisle between the seats. This describes cabin layout, not its radar identity or how many people are aboard.

A distance unit used in aviation and navigation. It is different from the ordinary mile used on UK road signs.

A navigation aid: equipment or a reference used to help aircraft find and follow a route.

The game’s aircraft for listening to electronic signals. It provides different information from the E-3D’s radar.

Fuel a tanker can pass to another aircraft. In Air Defender, AF shows this separately from F, the fuel used for the tanker’s own flight.

An aircraft has reached the area where it is meant to work, rather than still travelling there.

Weapons and ammunition. A base needs supplies of these to equip its aircraft.

The symbol marking a detected contact’s position. It can appear before a track has been formed. In Air Defender, the shape reflects track association and recorded radar information; it is not an identity or a guarantee of fresh detection.

An extra layer of information drawn over the map. Hiding a layer changes the display, not the objects in the simulation.

Move the view across the map without changing the zoom level.

Listening for signals sent by other equipment, rather than transmitting a radar pulse to obtain an echo.

One section of a planned flight path. For the tanker TRACK command, two map clicks set the main straight section.

What the aircraft carries for the job. In a supply order, this means the cargo you choose to deliver.

A request for, or report of, the tactical air situation: where relevant aircraft are and what is happening. In radio communications, this refers to the tactical situation.

One report of a detected position. The history dots behind a contact are plots showing earlier reported positions.

Positive identification: a report that the aircraft type has been confirmed. It is separate from permission to use weapons.

The engine or engines that power the aircraft.

Player Performance: the game’s measure of how you are doing. It is separate from public concern and the scenario’s tension.

Water falling from clouds, such as rain, snow or hail. It can reflect radar energy.

An altitude worked out from air pressure using a standard reference. It is not a direct measurement of the aircraft’s height above the ground beneath it.

Radar that detects energy reflected from an object. It does not need the aircraft to send a transponder reply.

How a radio signal travels from one place to another.

Public State: the game’s indicator of public concern, from Calm to Nervous or Scared.

Quick Reaction Alert: aircraft kept ready to launch when a contact needs to be investigated or a threat needs a response.

A repeating flight path with two straight sections joined by turns, rather like the outline of a running track.

Distance. For a contact it means distance from a stated point; an aircraft’s range means how far it can fly under stated conditions.

Replace weapons used during a flight so the aircraft is equipped for another mission.

The aircraft taking fuel from a tanker. For example, when a tanker refuels a fighter, the fighter is the receiver.

Bringing an aircraft back to a suitable airfield to land. It may return to its home base or land at another suitable airfield. Here, recovery does not mean repairing an aircraft or restoring a saved game.

Move an aircraft to another base. This is different from using it to carry a delivery of fuel or weapons.

A change in the direction of a wave as it travels through changing conditions. In the atmosphere, this can bend a radar beam.

A fighter control that restores its pairing with a remembered previous partner. It does not let you choose any nearby fighter as a new partner.

A planned meeting. For refuelling, it is where the aircraft meet before getting into position to pass fuel.

Give an aircraft a different job or destination after it already has a task.

Rules of engagement: the rules controlling when force may be used. In Air Defender, check the game’s ROE reference and the current scenario before ordering an attack.

Return to base: an order to bring an aircraft back to land. The aircraft still has to fly there, land and be prepared before it is ready for another mission.

A summary of the information held about a flight. Compare it with what the aircraft is actually doing.

The radar display: the map-like screen containing contacts, symbols and information.

An urgent order to launch aircraft. In the game, follow the launch messages to check when the aircraft actually take off.

Radar that sends an enquiry to an aircraft’s transponder and measures its reply. The reply can also carry information such as a code or altitude.

The one contact you are currently working on. Other contacts can remain hooked while you select it.

The stated height an aircraft can climb to while still meeting specified performance requirements. The game’s reference figure is not its current height or a guarantee for every situation.

The label beside an ATC report’s identity choices. Each letter button requests a classification for the track named in that report. Check the resulting identity because the change can be refused.

Signals intelligence: information gained by listening to and analysing electronic signals. In Air Defender, Nimrod R1 provides this listening role.

One aircraft, rather than a pair or a larger group.

A mission flown by an aircraft, from take-off to landing. Air Defender also groups related aircraft under a sortie channel so you can follow their mission together.

In Air Defender terminology, a report of confirmed target destruction. A track disappearing from the scope alone does not prove a SPLASH.

The code set on an aircraft’s transponder. A four-digit squawk is information to check, not a permanent aircraft identity.

A transponder identification action that makes the aircraft’s reply stand out on a compatible display. It is different from ordering a fighter to identify a contact.

A reference speed for the onset of a stall under specified conditions. A stall occurs when a wing or rotor blade exceeds its critical angle to the airflow and loses lift. It does not mean the engine has stopped.

An aircraft whose role includes attacking targets, such as targets on the ground. A type’s role does not establish the intentions of a selected contact or give permission to attack it.

The game’s supply action: arrange a flight to carry selected cargo, such as fuel or weapons, between locations.

Aircraft that help other aircraft or the radar picture. In these guides this means tankers, AWACS and Nimrod, each with a different job.

The moving scan display on a radar picture. Its visibility is separate from whether a station is powered.

A report that the pilot can see the contact. Seeing it is not automatically permission to fire.

An aircraft that can pass fuel to another aircraft while both are flying.

A layer in which air gets warmer with height instead of cooler. It can contribute to unusual radar-beam bending; the moisture conditions matter too.

How quickly time passes inside the simulation. At 2×, two seconds of game time pass for each real second; this is separate from screen frame rate.

Switch between two states, such as on and off, by using the same control again.

A tonne is 1,000 kilograms. Air Defender uses t for fuel held at an airfield; this is a mass, not a volume in litres.

The system’s record of a contact over time, built from related reports. On the scope it is shown using a symbol and available information.

The reference number the game assigns to a track, such as 007. It is different from the aircraft’s four-digit squawk code.

A display setting that keeps data for the selected and hooked contacts while hiding other data blocks. It does not remove aircraft from the game.

The group of information beside a contact, such as its height, speed and code. Also called a datablock.

Equipment on an aircraft that sends coded radio replies when questioned by a compatible radar system.

Tension State: the game’s indicator of the situation, from Peacetime to Heightened or Critical.

Recognition in a country of an aircraft design approved elsewhere. The report states which models and individual aircraft numbers it covers.

Official approval of an aircraft design against the rules that apply to that design. It does not describe the condition of one aircraft on today’s flight.

Unavailable for use because of a fault or other reported problem. AIRFRAME U/S is the game’s warning for an affected aircraft.

Coordinated Universal Time: a shared time reference. It may differ from the time on your local clock, including during British Summer Time.

In Air Defender terminology, a warning of an incoming hostile anti-radiation or cruise missile. Read the warning and track information; do not classify every new triangle this way.

Visual flight rules: rules for flying with the required visibility and separation from cloud, using outside visual references.

Vertical synchronisation: a graphics option that coordinates frames with your screen’s refresh to reduce visible tearing.

In Air Defender, FLASH - WEAPONS HOT names the fighter and target authorised for weapons use. The Heightened-tension message tells you to use ENG tasking if you intend to shoot down; the notification itself does not assign ENGAGE.

Firing or releasing a weapon. Finding or identifying an aircraft is not, by itself, permission to attack it.

A passenger-aircraft cabin wide enough for two main aisles between rows of seats. It describes cabin layout, not the number of people aboard a selected flight.

Air-to-air weapons have been expended. Check the aircraft’s actual remaining weapons and return or rearming status. It is a weapons-state report, not a low-fuel report.

The other fighter flying and working with the leader of a pair. Air Defender keeps track of this partnership even when the two map symbols are separated.

Experience points: points recorded for your player profile’s progress. They determine its level and help determine its rank. They are different from a lesson’s percentage score and the operational PP score.

In Air Defender terminology, PAN describes an urgent aircraft situation without immediate danger. The real-world radio urgency signal is PAN PAN: a safety problem that does not require immediate assistance. It is different from MAYDAY, the distress call, and from panning the map. Read the reported problem and the emergency information.

An engine system that burns extra fuel in the exhaust behind the turbine for additional thrust. It uses much more fuel. Reheat and afterburner mean the same system.

An engine with pistons moving inside cylinders. A crankshaft turns their movement into rotation; in the aeroplanes described here, it drives a propeller.

A gas-turbine engine whose fast exhaust produces thrust. Its turbine also drives the compressor.

A gas-turbine engine that also drives a fan. Some fan air bypasses the engine core; that airflow and the core exhaust contribute thrust.

A gas-turbine engine driving a propeller through a shaft and gearbox. The propeller supplies most of its thrust.

A gas-turbine engine supplying shaft power to equipment such as helicopter rotors, rather than relying mainly on exhaust thrust.