Return To TradeIP.Com  |  FAQs and Tutorials Page How-To: Flying with Air Traffic Control Getting more out of Multiplayer ATC sessions Note:  This set of Frequently Asked Questions deals with flying a flight simulator on a desktop computer. Don't use any of this information to fly a real plane, and remember that in this FAQ, many concepts have been simplified, and many more omitted altogether. This information is intended to help people get more enjoyment out of flying computer planes in a multiplayer setting, nothing more... What is ATC? ATC is short for Air Traffic Control. As you probably know, airplane pilots can't just hop in the plane and take off from most airports without talking to an air traffic controller on a two-way radio. Controllers use radar to look at airplanes in flight, and radios to give instructions to pilots. These instructions come in the form of clearances. ATC clearances are standardized ways of telling pilots what to do - which direction to fly, and at what altitude, for example. More on clearances in a bit... The air traffic control system helps keep planes from running into each other, and brings order to the skies. The ATC system is very highly-regulated, but for the purposes of Multiplayer (MP) flying, can be simplified so that armchair flyers (don't you hate that expression?) can get a better feel for what it might be like to fly for real. In the real world, there are many levels of air traffic control, from Ground Control, to Tower, to Approach and Departure, and enroute control at a terminal or air traffic control center. Enroute air traffic control consists of overflights that are handed off to a controller who watches the flight until it is time to hand it off to another controller. How does ATC work with a flight sim Multiplayer session? There is no single way or method of using ATC in a FS98 Multiplayer session. In FS98, the simplest way to provide ATC is for the controller to use the map view to look at the other planes, and a voice communications program such as Roger Wilco, to talk to them. The controller may act as a VFR, or Tower controller, or as Tower and Approach / Departure controller. It can be as simple as saying "Cleared to land," and "Cleared takeoff," and nothing more, or as complex as a full-blown CH Server / Client session requiring special software add-ons. It is up to the person hosting the session as to what level of ATC service he or she is willing to provide. Capabilities and skill levels of the controller, as well as the pilots, are a big factor in whether Multiplayer ATC works well or not. What is VFR? IFR? VFR is short for Visual Flight Rules, and IFR is short for Instrument Flight Rules. Under VFR, airplanes must remain in visual contact with the ground, and are responsible for seeing other airplanes in the air, and avoiding them. You might think, "Hey, it's up to ATC to keep the airplanes from hitting each other." But under visual conditions, pilots of big and small airplanes are always required to search the skies for, and avoid, other airplanes. Many VFR flights can proceed without the need for the pilot to talk to an air traffic controller at all. At small airports where there is no control tower, and in uncontrolled airspace, a VFR pilot can pretty much go where he or she pleases, subject to real-life restrictions that don't much concern us here. One restriction that would apply to a VFR flight is weather - if you can't see where you are going because of weather, then you probably shouldn't be there... An IFR flight is under positive control of the ATC system at all times. All IFR flights follow flight plans, which are filed with ATC. Among other things, flight plans contain the route the aircraft will fly. The pilot flies the route, and ATC watches the flight on radar. As the aircraft moves between sectors and passes out of radar range, different controllers will take over. To find their way around, IFR pilots use navigation instruments installed in the aircraft, and don't need to look at the ground to navigate. These instruments get data from ground-based navigational aids, and display the information to the pilot. The pilot uses maps, charts, and instrument approach plates, together with the instruments, to follow a specific air route. An IFR flight could theoretically proceed from takeoff to touchdown without the pilot ever talking to an air traffic controller. What types of clearances are there? At larger airports, a departure clearance is issued by a Clearance Delivery controller while the aircraft is still parked. An IFR departure clearance is based on your flight plan - for VFR flights without a flight plan, Clearance Delivery will assume you are flying a local sightseeing or training flight, and will simply tell you which runway to expect, then clear you for engine start and tell you to contact Ground Control. Smaller airports will probably not have a Clearance Delivery controller, so the pilot would contact Ground Control before starting engines. If there is no Ground Control position, the pilot would talk to Tower. If there is no Tower, the pilot would say his or her intentions over the Unicom frequency before taking the runway. Unicom is a common traffic frequency that all VFR flights in the area would listen to. Air traffic control services are not provided on Unicom frequencies, but it is still possible for an IFR flight to depart from a VFR-only airport with no tower. As long as visual conditions exist, the pilot can file an IFR flight plan with a Flight Service Station (FSS) over the telephone and contact ATC in the air, either an enroute Center or Departure control from a nearby larger airport. The flight is then under control of the IFR system. A departure clearance will include the runway to be used, and for IFR flights, the specific route the aircraft will be taking to its destination. This routing will include any amendments or changes that ATC has made to that route as filed by the pilot in the flight plan. A taxi clearance is issued by a ground controller once the aircraft is ready for engine start. This clearance will tell the pilot which taxiways to use to get to the desired runway for departure, and includes hold short instructions for runways, which must be read back by the pilot. "Hold Short" means, don't cross or enter the runway without permission. "Taxi into position" means, taxi onto the runway and wait there for your takeoff clearance. In a MP ATC session, you shouldn't enter the runway, much less take off, wihout a clearance. A takeoff clearance will be required at any airport where there is a control tower, and is normally issued by the Tower controller. "Cleared for takeoff," along with the runway number, means you are cleared to take off from that runway. In a MP session, you should have an idea of what you want to do, i.e. remain in the circuit or traffic pattern, do some local sightseeing, or fly to another airport. You should tell Tower what you want to do, at the time you are requesting clearance to taxi or take off. Tower will issue a landing clearance when your aircraft is in a position to land, and the runway is clear. In a MP ATC session, you shouldn't land without a clearance. What are patterns? Circuits? The pattern generally refers to the traffic flow that is in use, or has been established at a particular airport. A circuit generally means a trip around the pattern. These terms are often used interchangeably, i.e. "In the pattern" or "In the circuit." In Canada, the standardized path to be flown by aircraft in the vicinity of an airport is called the circuit, and in the US, it is called the pattern. You can visualize a typical airport traffic pattern as a rectangular box shape, aligned over the main runway. Turns in the pattern are usually to the left, and the pattern is usually flown at around 1,000 feet above ground level. At least one leg of the pattern is normally flown by inbound VFR aircraft, and student pilots can often be found flying the pattern over and over and over... VFR pilots arriving at an airport are expected to be able to visually navigate and maneuver their aircraft into position for landing, without receiving specific directions (headings or vectors) from the Tower - only a clearance to enter the control zone, a clearance into the pattern, and a clearance to land is usually required. In the real world, if you want to fly into an airport, you are supposed to know the various runway headings and the airport elevation in advance, so all you need to know when you want to join the pattern is, which runway is active at the time, plus winds. Until you get good at quickly calculating downwind and base leg headings in your head, or get used to a certain airport, flying the VFR pattern can be harder than it looks... In the flight sim world, we don't always have the proper maps, charts and facility directory, so we have to make do, and improvise. If you want to join an ATC session, you should at least know the bare minimum about the airport you want to fly into - you can get the runway headings and elevation from the FS98 facility directory, or if you are using scenery that is not part of the program, from the Internet. In any case, a VFR arrival, upon receiving a clearance to enter the traffic pattern, would fly a predictable, standardized path around the airport that would lead to a normal approach and landing. In order to expedite traffic flow, Tower will often clear an aircraft directly to a leg of the pattern. For example, looking at the diagram above, an aircraft arriving from the northeast, or the upper right-hand corner of the picture, might be cleared to a left-hand downwind for the runway (we'll call it Runway 09). An aircraft arriving from the northwest, or the upper left, could be cleared to a left base for Runway 09. An aircraft arriving from the south would have to join the crosswind leg, while an aircraft arriving from the west, would have the farthest to fly of all, and would normally join the upwind leg. You might ask why an aircraft arriving from the west would have to fly the pattern, when it could just descend and land straight ahead. The answer is, flying a straight-in approach when VFR can make it harder to judge perspective and distance from the airport, and is especially discouraged at fields where there is no tower. It is better to join the circuit, where it is possible to see the windsock while flying around the airport, as well as look at the condition of the runway, etc. Some busier airports have published VFR arrival routes that incorporate local landmarks such as bridges, chimneys, water towers, stadiums, etc. It makes it easier for Tower to ask an aircraft to report over the local water tower on the left base for the active runway, even before the aircraft has entered the control zone. In the real world, if a pilot has never flown into an airport before, he or she can always ask Tower for a little extra help in identifying ground references or runways - this is not recommended at the large, busy airports, however, where you should be prepared if you want to play in the "big leagues..." Tower will normally clear an aircraft in the pattern to visually sight and follow a preceding aircraft, and will also advise of any IFR or VFR traffic that could be a factor in seeing and avoiding. In good weather (the only time VFR aircraft are supposed to be active), IFR pilots are also supposed to watch for other traffic, but may tend not to look outside the airplane as much as a pilot flying VFR. What a real-world Tower will not normally do, is issue heading changes and speed restrictions to aircraft. If you are unfamiliar with the area, Tower can provide suggested headings to fly, but will not issue radar vectors. In a Multiplayer session, however, the controller may decide to do just that, and if you want to play, you should go along with it. In FS98, it is often harder to judge perspective, runway layout and distance to the runway, especially at unfamiliar airfields, than in a real aircraft. This is where ATC vectors can really come in handy... Do IFR arrivals always fly an IFR approach? No. At some airports, it is standard for inbound IFR's, airliners, etc. to receive a clearance to fly a left or right-hand, or straight-in visual approach to the active IFR runway. In clear weather, pilots checking in with approach control are issued radar vectors to a point close to the airport, at which time the pilots are asked whether they have the airport in sight. When they do, the visual approach clearance can be given. If there is traffic ahead, they are asked if they have the preceding traffic visually before they are handed off to Tower. Note that the flight is still an IFR flight until the flight plan is cancelled with the appropriate ATC agency, but as always in visual conditions, the pilots are required to look out the window for other aircraft. Why does ATC give out visual approaches to IFR inbounds? Mainly to save time and gas. The airlines like saving gas, and the pilots especially like saving time. It is also less of a headache for ATC to be able to pass along some of the responsibility for navigating, and seeing other traffic, to the pilots. The time and gas is saved because an aircraft that will be flying an ILS approach must be vectored to a 10 or 15-mile final, while an aircraft that has accepted a visual approach can be directed to turn final at the outer marker, just four or five miles out. Why is it so hard to fly the big jets in the pattern? Hard is a relative thing. In the flight sim world, flying a visual approach in an airliner requires different techniques than flying the ILS, or flying patterns in a smaller plane. It can be a challenge to maneuver a large aircraft onto a five-mile final - the views out the windows are not as good and it is easy to lose sight of the runway, overshoot or undershoot your turn, or to get your perspective messed up. Many Flight Sim pilots do not practice flying circuits, and don't practice hand-flying the larger aircraft, which is why radar vectors to the ILS approach seems to be the rule in many sessions. But it's a worthwhile skill to be able to fly visual approaches in the big jets, and it can be a lot easier to do if you keep a few things in mind: Don't take it out too far. If you fly out too far in any direction, you will lose sight of the airport, or lose your visual perspective relative to the runway. Try climbing straight out to 1,500 feet, then turn crosswind while levelling out your rate of climb. Don't spend too much time on the crosswind leg - as soon as you are established 90 degrees from the runway heading, start your turn downwind. In flight sim, airports and runways will often disappear from view sooner than they would in real life. You will probably have to make somewhat steeper turns than a real airliner would to compensate for this, so you can stay close enough to the airport to keep it in sight. Just keep it within reason, and fly high enough (2,000 to 2,500 AGL) so you don't lose the airport visually. It takes practice and experience to judge how much room you will need to turn a 747 - try an A-320 and take it from there. Fly at a reasonable airspeed. There is no reason to fly a large aircraft at more than 200 knots when close to the airport. If you fly any faster, you will probably get too far from the airport and lose your orientation to the runway. Naturally, you will have to configure the aircraft for slower flight. Find and use a flap setting that will give you good visibility over the panel, and a good margin of safety above the aircraft's stall speed. It is good practice to keep your speed up on final - try flying at 180 knots or so until five miles final, or at the outer marker, then smoothly reduce to final approach speed. Approach Control will sometimes ask you to "keep the speed up" or to reduce to minimum approach speed, to help with sequencing, and they will appreciate it if you can comply. Keep the patterns consistent. Try to do it the same way every time, with the same aircraft, until you are familiar with how the airport looks from all angles. Then you can vary your airspeeds and try it with different aircraft. Turning final can be tough to nail The single most difficult thing to get right is the turn from base to final - it is hard to know exactly when to start your turn. Turn too early or too late and you will not have much time to get properly lined up with the runway. A good landing will only result from a stable, well-aligned approach, and judging when to start your turn can only come from experience with flying a particular aircraft. The weight of the aircraft, the altitude and airspeed, the winds, and the "look" of the airport and scenery on the approach, will all be factors. Get used to doing it a certain way before you change anything, and get used to judging your distance from the runway on downwind and when turning base. Pick an ILS runway with DME to start, and use the DME readout, along with your out-the window views, to develop skill in estimating your distance from the runway. When you get to the point where you can consistently turn a large airplane like a 767 onto a five-mile final, then try it at another airport, or with another aircraft. If you can't get to that point, then practice with smaller aircraft, and smaller patterns, until you are ready to move up. Can a VFR aircraft fly an IFR approach? Yes, a simulated ILS approach, for example, can be flown on request by a VFR pilot, and traffic permitting, ATC will likely approve it. But the aircraft is not part of the IFR system, and must remain VFR at all times, i.e. clear of clouds, and the pilot is responsible for separation from all other aircraft. This type of flying can obviously be done only in clear weather, and is usually done as part of training. In that case, there will be two pilots on board, and the instructor will be able to keep looking out the window for traffic, talk on the radio, etc. What are vectors? At airports for which a published instrument approach exists, and where Arrival or Approach control is provided, rather than have inbound aircraft fly the full published approach, radar vectors are normally issued to bring aircraft into position to carry out the final approach phase. Since flying a full published approach requires things like procedure turns and outbound and inbound legs, this saves both time and fuel. Radar vectors are also issued to aircraft flying in, or near, an airport traffic area, so that ATC can provide for aircraft separation in the radar environment. These can be issued by the Approach or Departure controllers, and consist of instructions to fly a particular heading. IFR pilots can also normally expect altitude and speed restrictions along with their clearances. Speed restrictions are given in multiples of 10, i.e. "Maintain 180 knots or better to the marker," not "maintain 175 knots." The same is true for vectors - aircraft are cleared to turn either left or right to a compass heading that is a multiple of 10, so it would be, "Turn left to 090 degrees," not "Turn to 087 degrees." The exception might be when a Multiplayer or CH controller is "talking" a pilot through a full published approach. That would be unusual, and would not happen in the real world. In FS98 Multiplayer flights, it is difficult to use the FS98 map view to provide radar vectors, for example, to an ILS approach. It can be done, but not very precisely. And it is easier to do for smaller aircraft, which can turn in a much smaller area than large aircraft, and are less likely to overshoot the localizer. CH Server / Client is much more suited to this type of session. Finally... There is a fundamental difference between how VFR and IFR flights get handled in the real world, a difference that often gets blurred in Multiplayer ATC sessions. This is why you can sometimes find youself getting "vectored" around the traffic pattern, with Tower calling each turn for you with headings and airspeed restrictions, or alternately, clearing you to land on an ILS approach before you have even intercepted the localizer. It's up to the person hosting an ATC session to sort out how the session is going to run, and this is where communication comes in handy, in the form of adding more detail to the flight board posting. For pilots, knowing in advance whether VFR or IFR type flying, or both, will be taking place, can reduce confusion and help streamline the session for everybody. To sum this FAQ up, the success of any Multiplayer or CH session depends on keeping procedures as simple and straightforward as possible, and on the controller and pilots not exceeding the limits of their abilities. It is possible to have an enjoyable, fun ATC session using only the basics, such as those covered in this FAQ. Happy flying... Top of this page