Collision Avoidance

Collision Avoidance and Clearing Turns

Collision Avoidance

Collision avoidance is a very important aspect of flight safety and is part of the fundamental tenet of see an avoid. This lesson highlights the key aspects of collision avoidance in the air. The student pilot should read the references provided for more comprehensive coverage of this topic.

References

• Collision Avoidance section of the Airplane Flying Handbook (page 1-11 [25]
• FAA Advisory Circular 90-48D, Pilots’ Role in Collision Avoidance
• AIM paragraph section 4−4−15. Use of Visual Clearing Procedures
• AIM paragraph section 8−1−6. Vision in Flight
• AIM paragraph section 8−1−8. Judgment Aspects of Collision Avoidance

Clearing Turns

Clearing turns are used to clear an area of traffic before doing maneuvers, but exactly how to do this is not specified by the FAA. The Airplane Flying Handbook says this about clearing turns:

There are many different types of clearing procedures. Most are centered around the use of clearing turns. The essential idea of the clearing turn is to be certain that the next maneuver is not going to proceed into another airplane’s flightpath. Some pilot training programs have hard and fast rules, such as requiring two 90° turns in opposite directions before executing any training maneuver. Other types of clearing procedures may be developed by individual flight instructors. Whatever the preferred method, the flight instructor should teach the beginning student an effective clearing procedure and insist on its use. The student pilot should execute the appropriate clearing procedure before all turns and before executing any training maneuver. Proper clearing procedures, combined with proper visual scanning techniques, are the most effective strategy for collision avoidance.

Some possible ways to do clearing turns include:

• Two 90 deg turns in opposite directions
• A 180 deg turn
• A 360 deg turn

Regardless of the turn or turns used the idea is always the same: to scan for traffic around your present location to make sure that the entire 360 deg area is clear. Also, it is usually best to start with a turn to the left since any aircraft overtaking you should be passing you on your right.

Additional ways to check for traffic in your area

While clearing turns and scanning for traffic are the cornerstone of collision avoidance, there are a number of additional things that you can do to further improve your traffic awareness:

Cockpit Traffic Displays

Many pilots now have cockpit traffic displays available to them that were unheard of just a few years ago. These include ADS-B, Active Traffic, TIS, etc. Depending on the aircraft and equipment, this information can be displayed on the installed avionics and/or handheld devices such as an iPad. Either way, these systems can be very helpful in assisting you in the task of avoiding traffic in your area.

But as helpful as cockpit traffic displays can be a few notes of caution area warranted:

1. For various reasons, not all traffic will show up on an electronic traffic display. Never depend solely on such a display and always visually observe outside the aircraft for traffic whenever able to do so.
2. A traffic display does not improve your safety if you spend all of your time looking at the display inside the cockpit. Make sure to look for traffic outside of the cockpit, including areas that the traffic display indicates are free of traffic.

ATC Traffic Advisories

In many practice areas you can ask for traffic advisories from either your local tower (if close enough to their airspace) or from ATC approach/departure control or center.

Monitor the local Advisory, CTAF, Tower, or ATC frequency

Monitoring the appropriate frequency is a great way to gain insight about local traffic. It will often give you a heads-up on arriving and departing traffic, as well as other traffic that may be maneuvering in the area. In some practice areas it may be appropriate to self announce your location and intentions in addition to just monitoring for others.

Lights

To improve your visibility, and therefore safety, the FAA now recommends that you have all of your your lights on day and night. Please see my lesson on aircraft lights for more details.