Chaotic Traffic Pattern: Sedona, AZ (KSEZ)

I recently flew friends to Sedona, AZ (KSEZ) for brunch on a beautiful Sunday morning. The flight from the Las Vegas area was uneventful, but the arrival at KSEZ (video below) illustrated the need for clear communications and standard traffic pattern procedures at busy non-towered airports.

Sedona, AZ (KSEZ) on a sectional chart

KSEZ is famous for its runway located on a mesa above the town, which is surrounded by spectacular red rock formations and supposedly is home to at least one spiritual energy vortex. Some wags call KSEZ the USS Sedona, because landing there is as close as most pilots will come to landing on an aircraft carrier (the other famous candidate for landlubbers is Catalina, CA; KAVX).

Closer view of the airport on a sectional chart

The airport is at 4830 MSL elevation; traffic pattern altitude is 6003 for piston aircraft, per the remarks in the Chart Supplement. It has one runway, 3-21. Runway 3 slopes up, and it is the preferred choice for landing when winds are light. Runway 21 is usually the best choice for takeoff. Left traffic is designated for both runway ends; downwind and base west of the airport when using runway 3; downwind and base east of the airport when using runway 21.

The recently updated AC 90-66B–Nontowered Airport Operations describes the recommend procedures for entering and flying the traffic pattern at a non-towered airport, and it provides examples of best practices for communicating on the Common Traffic Advisory Frequency (CTAF) assigned to each airport.

The airport was busy on that Sunday morning, mostly with arriving traffic as we approached at about 1100 MST.

Arriving at KSEZ

But the problem during this approach and landing wasn’t really the number of airplanes trying to use the airport. Instead, it was difficult to develop a good picture of the traffic around the airport and to anticipate the actions of other pilots because:

Some pilots overflew the airport to enter the downwind directly or entered downwind directly rather than flying a 45-degree entry. Now, the 45-degree entry isn’t required, and AC 90-66B discusses two options for joining the downwind if you overfly the airport.

Traffic pattern entry after crossing overhead at midfield.

But the advisory circular also notes that:

11.3 Traffic Pattern Entry. Arriving aircraft should be at traffic pattern altitude and allow for sufficient time to view the entire traffic pattern before entering. Entries into traffic patterns while descending may create collision hazards and should be avoided. Entry to the downwind leg should be at a 45 degree angle abeam the midpoint of the runway to be used for landing. The pilot may use discretion to choose an alternate type of entry, especially when intending to cross over midfield, based upon the traffic and communication at the time of arrival. [Emphasis added.]

Note: Aircraft should always enter the pattern at pattern altitude, especially when flying over midfield and entering the downwind directly. A midfield crossing alternate pattern entry should not be used when the pattern is congested. Descending into the traffic pattern can be dangerous, as one aircraft could descend on top of another aircraft already in the pattern. All similar types of aircraft, including those entering on the 45 degree angle to downwind, should be at the same pattern altitude so that it is easier to visually acquire any traffic in the pattern.

AC 90-66B

The other issue that sunny Sunday morning was confusing or confused radio calls and position reports. Using local landmarks like “the high school” doesn’t help folks who aren’t familiar with the area. As AC 90-66B notes:

Transient aircraft may not know local ground references, so pilots should use standard pattern phraseology, including distances from the airport.

AC 90-66B

The recommendations in the AC also note that:

When referring to a specific runway, pilots should use the runway number and not use the phrase “Active Runway,” because there is no official active runway at a non-towered airport. To help identify one airport from another when sharing the same frequency, the airport name should be spoken at the beginning and end of each self-announce transmission.

AC 90-66B

Finally, some of the transmission where confusing, perhaps because the pilot simply misstated a runway number, pattern leg, or intentions. For example, one pilot said, “Cirrus xxx, on a straight-out departure runway 21, coming back for a straight-in departure runway 3.” Those were slips of the tongue, but they certainly didn’t help others understand the pilot’s plan.

Other pilots reported entering the downwind from the north, probably via a direct entry (without a 45-degree leg), but it was hard to be sure, and at least one aircraft apparently flew inside another as they entered the downwind.

As you can see in the video, I made a 360-degree turn while on the 45 leg to create more space behind the Baron that joined downwind ahead of me after crossing over the airport at midfield. We were a little too close for my comfort, and I didn’t want to extend my downwind behind the twin, which needs more room to maneuver.

In the end, we all arrived safely, but the traffic pattern was more chaotic than necessary. Flying a few extra miles to set up west of the airport for a 45-degree entry would have allowed everyone more opportunities to develop good situational awareness, to minimize last-minute maneuvering near the airport, and to adjust the pattern to accommodate arrivals and departures.

Another note for pilots: My Bonanza is equipped with an altitude-compensating fuel pump. It adjusts the mixture based on ambient pressure, so even at high-altitude airports such as KSEZ, I set the mixture to full rich for takeoff and landing, and I check for the appropriate the fuel flow based on a table in the airplane flight manual. If your aircraft doesn’t have such a system, and most don’t, you should refer to the performance data in your POH or AFM and set the mixture according the the information in that handbook when operating at high density altitudes.

2 Responses to Chaotic Traffic Pattern: Sedona, AZ (KSEZ)

  1. Chris Bowman says:

    Oh my god! Thanks for the excellent video. Nothing like a beautiful VFR day at a destination airport. Maybe there should be more instruction in this area, like “vectors for spacing”, or just go on a short side trip to let things settle down a bit. The 360 worked out, but it sure was tight. Good analysis. Small airports can take on a bit of their own personality from the pilots who are based there.

  2. jsrickel says:

    Thanks for the great article and video. May heart is still racing and I’m just sitting at my desk. Must have been quite exhilarating from your position.

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