Radar services
The en route services provided by air traffic control (ATC) are often referred to generically as radar services. Pilots on an IFR flight plan are almost always in contact with ATC, and under radar control. Since it may be impossible for pilots to see and avoid traffic in instrument meteorological conditions (IMC), ATC uses radar to identify and track aircraft and coordinate everyone's course, altitude, and speed to ensure that all remain safely separated in the skies. By assigning a unique transponder code to each aircraft that they are in communication with, as well as monitoring aircraft displaying a VFR 1200 code on the transponder, controllers can keep track of all the aircraft in their airspace. (See the sidebar - Transponder Procedures and Squawk Codes.)
In addition to providing basic separation, ATC sequences aircraft as they depart and arrive at airports, and assists in any number of ways, providing weather and altimeter settings, passing on pilot reports, handling special requests, and helping out in an emergency.
In VFR flying, we often refer to radar services as flight following, radar advisories, or traffic advisories. Outside of Class B, C, and D airspace, radar services are provided to VFR pilots on a workload-permitting basis - the controller's workload. (See the sidebar: "The ABCs of B, C, and D.") Using these radar services can ease our workload as pilots as well, and greatly enhance safety. As a safety-conscious pilot, you owe it to yourself to take advantage of them.
A second pair of eyes
Perhaps the most important advantage of using radar services is having what amounts to a second pair of eyes to help you look for traffic. Although not infallible, the keen radar vision of ATC can detect traffic long before a pilot can see it. ATC will sometimes suggest a heading or altitude to avoid potential conflicts with unseen aircraft.
Almost nothing is more important than being aware of the weather. While flight watch and flight service stations are the primary sources for en route weather updates, ATC will also provide limited weather information. When ATC initiates radar services or hands you off to a new controller, you will be given the local altimeter setting. But by listening closely, you can pick up a lot of other useful information. Controllers may provide other pilots on the frequency with local wind and weather information, especially when conditions begin to change. ATC also provides warnings to pilots regarding wind shear and other potentially hazardous conditions. You're likely to hear other aircraft providing unofficial pilot reports, particularly with regard to turbulence, visibility, and the bases and tops of cloud layers. If you are unable to contact flight watch or a flight service station by radio to check on the weather at your destination, ATC should be able to pull up the weather information you are seeking.
Navigational assistance
VFR pilots are responsible for their own navigation, but in some cases, ATC can lend a helping hand. ATC frequently assigns headings and altitudes through busy airspace to keep aircraft safely separated. To the uninitiated, this practice may be disconcerting, as it can foul up carefully planned navigation. When ATC says, "resume own navigation," the pilot is on his own to get from wherever he is to his destination.
If the pilot has been paying attention, watching the landmarks and tuning in navaids, it may be no problem to point the aircraft in the right direction. Sometimes pilots are sent far off their planned course and are too busy with traffic avoidance to keep pace with their position. When the vectoring (a vector is a heading the controller instructs a pilot to fly) ends, they can find themselves somewhat disoriented. If this happens to you, simply ask ATC to suggest a heading. The controller can quickly provide a vector to keep you moving in the right direction while you get your navigation back on track.
Another helpful bit of navigational information is groundspeed. If you have been asked to fly at a different altitude than you planned and you've been diverted off course, you may find that you simply aren't arriving at your checkpoints on schedule. ATC can probably tell you what your groundspeed is to help you adjust your schedule.
Having problems finding an unfamiliar airport? ATC will typically alert you when you are about 10 to 12 miles from your destination. ATC usually won't terminate radar services until you have the airport in sight, and they may help you locate the field if you're having trouble identifying it. Once you have the field in sight and ATC has provided any additional traffic advisories, the controller likely will terminate radar services and advise you to change to the tower or unicom frequency. If not, ask to change frequencies.
In certain situations, ATC can also provide local communication and navigation frequencies. If you suddenly need to contact an airport control tower, find a unicom frequency, or tune in a navaid, and you're having trouble coming up with the proper frequency, ATC may be able to immediately provide you with the needed frequency.
Emergency services
Another excellent reason to use radar services is the assistance provided in an emergency. We're all taught the importance of filing a flight plan for VFR flights. While this is an important safety measure, a flight plan goes only so far. Remember that if you run into trouble, a search will not be initiated for at least 30 minutes after your estimated time of arrival. If the problem occurs early in your flight, you could have a long time to wait for help.
If you are receiving traffic advisories from ATC, however, and you experience an emergency, you can immediately notify the controller. At times like this, ATC can be your best friend, providing instant assistance, such as vectors to a nearby airport, a heading to take you out of instrument weather and back to VFR conditions, or other critical information. Also, in the event that you have to make an emergency off-airport landing, ATC can dispatch help immediately to your exact location since the controller has been tracking you on radar.
Everywhere you want to be
Most VFR pilots associate ATC and radar services with tower-controlled airports, or Class B, C, and D airspace. The extent of radar coverage and the availability of radar services are much broader. In fact, with the exception of a few isolated low-altitude areas in the mountainous western United States, air traffic control radar blankets the country. Radar services are available almost everywhere you want to be throughout most of the United States.
Pilots who don't frequently use radar services may wonder just who to call to start service. To find the right frequency, begin by looking at your sectional chart and locating your airport, or any nearby airport served by an instrument approach procedure (IAP). All controlled airports have instrument approaches, and any airport located within an area of magenta shading also has an IAP. Next, look on the appropriate chart for the communications frequency or look up the airport in the Airport/Facilities Directory (A/FD), and check under the communications section of the listing. An R within a circle identifies the frequency for radar services. The listing begins with the name of the facility (e.g., Boston, Cleveland, Denver, or Philadelphia) followed by "APP CON" (approach control), "DEP CON" (departure control), or "APP/DEP CON" (approach and departure control). Simply call the appropriate controller on the published frequency and ask for radar services. (See the sidebar "Making Contact.")
A flight service station specialist also may be able to provide you with an ATC frequency for the area you are flying in. Finally, many GPS and loran databases can display an ATC frequency based on your present position.
Attitude and altitude
Radar services are available to VFR aircraft on a workload-permitting basis, and numerous factors may determine whether or not a controller has the time to talk to you. First, it helps to use good communications procedures and techniques. Think before you speak, use proper etiquette (don't transmit without listening first), and know and use standard radio phraseology.
Another factor in determining whether or not services are provided is altitude. I find that I am more likely to get assistance when flying at higher altitudes. Part of the reason for this is that we become more important to ATC as we fly higher. Faster aircraft and those on IFR flight plans typically fly higher than 3,000 feet agl. If you are operating within the altitudes frequented by IFR aircraft, ATC may be more eager to communicate with you.
Another advantage of flying higher is that radar coverage is typically better at higher altitudes. The shape of areas of radar coverage can be thought of as large inverted cones. At lower altitudes, there are often gaps between the coverage provided by the different radar facilities, and controllers may be unable to hand off an aircraft from one area to the next. The process flows much more smoothly at higher altitudes where there are no gaps in coverage. If you're headed for a busy area, it's a good idea to get radar services early from the less busy controllers in outlying areas. By getting into the system while controllers are less busy, you're more likely to get a handoff to the controllers in the busy areas.
Still pilot in command
Remember that radar service is a form of assistance for the VFR pilot, but the pilot in command still has final authority and responsibility for the safe operation of the aircraft. Accepting instructions from ATC does not relieve the pilot of any of his responsibilities. The controller can't see the clouds and could unknowingly vector a VFR pilot into IMC. If a controller issues a heading or altitude inconsistent with VFR cloud clearance requirements, tell the controller you're unable to maintain VFR and suggest an alternative heading or altitude.
Once you've been granted radar services, keep your ears and mind tuned in to the conversation. A sure-fire way to lose radar services is to not pay attention. If you miss a call, you'll probably be forgiven. If you miss several calls, expect a reprimand, and don't be surprised if your service is canceled with a curt, "radar services terminated, squawk 1200, remain clear of the Class B airspace."
It turns out my ground instructor was right. Flying IFR is simpler than flying VFR in many respects. But that the services that help make IFR flying easier are available to VFR pilots as well. All you have to do is ask.
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