Phoenix Approach had just cleared the aircraft for a practice Instrument approach behind South Mountain to Chandler’s Runway 04 Right, when a plane cut across the approach path.

The aircraft on the approach procedure was  turning inbound, forcing the pilots to manuever to avoid a collision.

This scenario, and variations of it, is played out a few times a year at DECTU, a waypoint south of South Mountain, where pilots enter their final approach for the RNAV (GPS) Runway 04 Right Instrument Approach Procedure to Chandler Municipal Airport (CHD).

This week, an aircraft “pretty much right at DECTU” passed through 4000 feet MSL, while performing aerobatic maneuvers, according to a high-time pilot who witnessed it. The altitude is the same as that for pilots entering the final approach course for Chandler.

The incident is a reminder for all pilots operating in visual conditions that regulations place responsibility on them to see and avoid other aircraft.

DECTU lies in the middle of popular flight-training airspace east of the Estrella Mountains and south of South Mountain. It’s a prime location for a possible midair collision between pilots on practice Instrument approaches into CHD and those doing airwork.

So, how do you reduce the chance of ruining your day with a near-miss or, worse, a midair collision? Here are a few basic tips:

1. Know your airspace ahead of time. Study the charts and plan accordingly for the type of airwork you will be doing. Performance maneuvers near waypoints, airways,  and controlled airspace is probably not a good idea.

2. Get on frequency for the area, or even multiple frequencies. For the South Practice Area behind South Mountain, the flight-training frequency is 122.85 Mhz. Make accurate position reports frequently and especially before entering a training maneuver. If you are near an airport or charted waypoints, monitor the frequency of the controlling agency. In this case Phoenix Approach and/or Chandler Tower.

3. Clear the area! Remember to always do clearing turns before starting any maneuver.

4. If you are a pilot practicing an Instrument approach, remember that you still also have the responsibility to see and avoid other aircraft, even if ATC clears you for the practice approach procedure. If under the hood, make sure that your safety pilot maintains a vigilant scan for other aircraft outside.

• Show up Saturday, Feb. 16, at 9:30 a.m. at Chandler airport for an FAA Safety seminar on local airspace. Scottsdale FSDO Operation Safety Inspectors will review VFR flying hazards and provide recommendations for safe operations. More details, and registration is here: http://faasafety.gov/SPANS/event_details.aspx?eid=48295&caller=/SPANS/events/EventList.aspx?statecd=AZ
• For more information on this topic, see the AOPA article “Avoiding Close Calls.” It’s at: http://flighttraining.aopa.org/magazine/2001/December/200112_Features_Avoiding_Close_Calls.html

Add your own comments below on your experiences in the practice areas, or things you’ve learned on how to avoid a close call.