Traffic or Tragic Pattern: A Pilot's Choice

I hope you're not one of those pilots who blow into the traffic pattern and scatter all the other pilots like frightened quail. In particular, I hope you make it easy for others to see you when entering the pattern. We're taught to enter the pattern at a 45 degree angle to the downwind leg. But where you intercept the downwind leg has a lot to do with how easy it is to see other airplanes as well as how easy it is to be seen by other pilots.

One of the common mistakes pilots make when entering is to aim for the center of the runway at a 45 degree angle (point A) as shown in Figure 1 below. Aiming for the center of the runway (point C) often causes you to intercept the downwind leg at a point where other airplanes are turning from crosswind to downwind (point B). This makes it very difficult for these airplanes to see you. It makes it much more likely that you won't see them, either.

Figure 2 shows the proper way to enter the pattern. Enter at a 45 degree angle to the downwind in level flight (point D) ABEAM the midpoint of the runway (point E). To do this, you often have to aim at (or near) the runway threshold (point F) during the entry. If no pattern altitude is recommended, use 1,000 AGL as your altitude. Doing so should prevent your traffic pattern from becoming a tragic pattern.

If you're still not convinced that entering the pattern at the midfield point is important, then read the following NTSB report.

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.

On February 15, 2000, at 1729 hours Pacific standard time, a Cessna 172N, N6479D, collided in midair with a Piper PA-28-140, N84PB, while in the traffic pattern at Palm Springs, California. The Cessna was substantially damaged and the certified flight instructor and his two students received minor injuries. The Piper sustained minor damage; however, neither the certified flight instructor nor his student was injured. The Cessna and the Piper were both being operated as instructional flights. The Cessna by Bermuda Dunes Air Service and the Piper by Alliance International Aviation, both under 14 CFR Part 91 when the accident occurred. The Cessna was originating from the Palm Springs Regional Airport, Palm Springs at the time of the accident, while the Piper flight had originated from the Chino airport, Chino, California, about 1650. Visual meteorological conditions prevailed at the time and no flight plans were filed. The Cessna had been cleared for closed right traffic on runway 31R and was in a turn from crosswind to downwind. The Piper had been cleared into the airport traffic area and told to report 2 miles out on a 45-degree entry to the downwind for runway 31R. During takeoff, the Cessna had been advised of a Piper inbound from the northwest by the tower operator. The tower operator had advised the Piper of two Cessna airplanes, in closed right traffic for runway 31R, on the pilot's initial call for a landing clearance. Both flights had acknowledged their traffic advisory by responding to the tower operator. A review of the tape-recorded tower communications failed to identify a position report from the Piper at 2 miles from the airport as the tower had requested. About 1,500 feet msl both aircraft collided opposite the departure end of runway 31R. The Cessna was in a right-banked turn to the downwind. The Piper was entering the downwind on about a 30-degree intercept angle. During the collision, the left wingtip from the Cessna was struck by the propeller and lower engine cowling of the overtaking Piper. The Cessna's left wing from the outboard section of the aileron separated during the collision. Numerous fragments from the wing were recovered from 33 degrees 50.65 minutes north latitude and 116 degrees 30.02 minutes west longitude, about 0.25 miles east of the intersection of Gene Autry Trail and Vista Chino. After the collision, the Cessna entered an uncommanded descending left spiral. The instructor took the controls from the student and throttled back. As the airspeed slowed he was able to gain some control and initiated a forced landing to a sandy wash about 0.75 miles east of the approach end of runway 31R. After the collision, the instructor in the Piper also took the controls from his student and requested a low pass over runway 31R. He wanted to obtain a visual inspection of his landing gear prior to landing. He was cleared for the low pass and was advised that his gear appeared down and in position. He then landed and taxied to the ramp without further incident. During interviews with both instructors, each acknowledged receiving a traffic advisory; however, neither instructor reported seeing the other aircraft at any time prior to the collision.

For more information on this subject, see "Aviation Speak: Traffic Pattern," "Traffic Pattern Entries," Continuing Education: Upwind Entries," and "No Dumb Questions: AIM Legality."