The Traffic Pattern

Click to watch a video on the traffic pattern

To maintain a smooth flow of traffic in the vicinity of an airport, airplanes fly a traffic pattern.

The traffic pattern, normally flown at 1,000 ft (305 m) above ground level (AGL), is a rectangular course with the runway as one side of the rectangle. Unless the traffic pattern indicators or published airport procedures indicate otherwise, you should make all turns to the left while flying a traffic pattern.

A basic landing pattern has three legs:   

1. Downwind: The first leg is flown parallel to the runway opposite the direction of landing. The distance from the runway depends on the type of aircraft you're flying, but generally you should fly the downwind leg 0.5 to 0.75 mi (1.0–1.5 km) from the runway. Start your descent when you're abeam—directly across from—the point on the runway where you want to touch down.
2. Base: This leg is oriented 90 degrees to the runway. Turn to the base leg when the end of the runway you're landing on is at about a 45-degree angle behind your wing.
3. Final: The final leg is aligned with the runway centerline in the direction of landing. In other words, you're flying toward the runway during final.

Entering the Traffic Pattern

As a general rule, you should enter the traffic pattern on a 45-degree angle, flying toward the center of the runway you intend to land on.The goal as you enter the pattern is to merge smoothly with other traffic. Keep these basic points in mind:

1. Keep a sharp lookout for other aircraft. Most midair collisions occur near an airport in good weather.
2. Make sure that you complete the descent to traffic pattern altitude before you enter the downwind leg. Many midair collisions occur when an aircraft descends onto another airplane that's already in the traffic pattern.
3. If you can't determine which runway and traffic pattern is in use before you approach the airport, fly over the middle of airport at least 500 ft (150 m) above traffic pattern altitude. Look for the wind sock and traffic pattern indicators. Then enter the traffic pattern by flying a safe distance from the airport and setting up on a 45-degree entry leg.

Leaving the Traffic PatternYou fly a traffic pattern when you depart an airport, too. Immediately after takeoff, you are on the upwind leg of the pattern. You should adjust your flight path to track the extended centerline of the runway.

1. If you plan to leave the pattern generally opposite the direction of takeoff, fly straight ahead until you're about 0.5 mi (0.8 km) from the departure end of the runway and within 300 ft (90 m) of pattern altitude. Then turn 90 degrees to the crosswind leg. Make this turn in the direction of the traffic pattern (usually left). Continue climbing to traffic pattern altitude and turn downwind 0.5 to 0.75 mi (1.0–1.5 km) from the runway.
2. If you plan to leave the pattern in the general direction of takeoff, continue climbing to pattern altitude and then turn 45 degrees in the direction of the traffic pattern (usually left).At a safe distance from the airport, turn on course and continue climbing to cruise altitude.

Runway Orientation and Numbers

Runways are laid out to take advantage of prevailing winds so that most of the time aircraft can take off and land into the wind.

Numbers

Runways are named according to the direction they face, relative to magnetic north. For example, a runway aligned with a magnetic heading of 90 degrees (east) is called runway 09. The number is rounded to the nearest 10 degrees and the trailing zero is dropped.

Runways have two ends, so each takeoff and landing surface is actually two runways. For example, runway 09 represents the takeoff and landing surface that's pointed east. If you take off or land on the same runway surface but from the opposite direction, you're using runway 27 (its magnetic heading is 270 degrees, or west).

Some airports have parallel runways to expedite takeoffs and landings. The same runway-naming convention applies, but the letter "L" or "R" is added to indicate the left or right runway. For example, parallel runways aligned with a magnetic heading of 210 degrees are designated 21L and 21R. A few busy airports have three parallel runways. The middle runway has the letter "C," for "center," added to its numerical designation.

Runway Markings

Runways come in three basic types:

1. A visual runway is used only for VFR flights. No instrument approach procedure is associated with a visual runway. A visual runway usually has a threshold marking, a runway number, and stripes designating the centerline and the runway edges. It may also have fixed-distance markers—two large, white rectangles on either side of the centerline about 1,000 ft (305 m) from the threshold.
2. A nonprecision runway supports both VFR and IFR traffic. As indicated by its name, this type of runway is served by a nonprecision instrument approach, usually a VOR or NDB approach. In addition to the markings used on a visual runway, a nonprecision runway also has threshold markings.
3. A precision runway supports a precision approach, usually an ILS. Precision runways have all the marks found on a nonprecision runway, plus touchdown zone markings. These marks appear at 500-ft (150 m) increments, beginning 500 ft from the threshold. These additional marks help pilots make the transition from instrument to visual flight and define the proper touchdown point for an aircraft flying an ILS.

Overruns and Displaced Thresholds

Some runways have overrun or blast pad areas. These aren't strong enough to support an airplane and are marked by large chevrons. You might also see a series of arrows pointing to the beginning of a runway. They indicate a displaced threshold.You can use the area ahead of the displaced threshold for taxiing and takeoff, but landings are prohibited on this part of the runway.