See and avoid

A recent fatal midair collision in Southern California as well as news articles about a variety of small unmanned aircraft systems has brought see-and-avoid principles to the forefront, warranting a review of our see-and-avoid obligations. In addition to reviewing regulatory requirements, it is important to review the way we carry those regulatory mandates into the cockpit and act with appropriate care as pilots.

Both 14 CFR 91.111 and 91.113 apply to aircraft separation issues: 91.111 prohibits operation so close to another aircraft so as to create a collision hazard, and 91.113 lays out the structure of right-of-way priorities in the air.

In the news recently were reports of small unmanned aircraft being operated in close proximity to aerial firefighters. Operators of small UAS must see and avoid other aircraft (and respect temporary flight restrictions too). Before small UAS were prolific, there were documented cases of airmen in manned aircraft (at least being accused of) pushing a right-of-way priority granted to them by 91.113 so far as to create a collision hazard in violation of 91.111.[1]

This begs the question: Does your obligation to see and avoid other aircraft trump any right-of-way priority you may have? The answer is a resounding yes. FAR 91.111(a) has no exceptions: A pilot’s obligation to see and avoid other aircraft at all times (with the exception being in actual instrument meteorological conditions and on an IFR flight plan) is completely independent of any right-of-way claim.

Now the real question: How do you comply with this regulation? What steps do you take to ensure that you see and avoid other aircraft?  I would argue that our duty to see and avoid other aircraft starts with education, then involves preflight planning, and is demonstrated by specific overt acts throughout the course of a flight.

Have you taken the opportunity to learn about when and where midair collisions are likely to occur? Have you matched that information with your route of flight? Do you use all resources at your disposal in the cockpit? If your answer is yes, then you know what I’m about to say.

In a report surveying NTSB data on midair collisions, and near midair collisions, the authors of a report for the American Institute of Aeronautics and Astronautics found that 54 percent of midair collisions occur between aircraft traveling the same direction. That is, one aircraft is overtaking another aircraft and runs into it from behind. They also found that over half of all midair collisions occur in or near the airport traffic pattern. In the traffic pattern, 82 percent of conflicts result from one aircraft overtaking another aircraft from behind. When not near an airport, the distribution of conflicts varies, with the most conflicts (29 percent) occurring between two aircraft with about a 90-degree difference in heading.[2]

These data tell us that we need to be most vigilant as we approach airports. But as we approach airports, we are distracted by things like pattern entries, airport diagrams, frequencies, and the ever-present checklist. This complicates matters more as researchers have found that your ability to see and avoid another aircraft actually decreases as your attention is distracted by other matters. It’s not just that your attention is diverted—your visual field actually narrows as your workload increases.[3]

Do you allow yourself to be distracted from your obligations in the cockpit (I’m talking about your iPad, with or without an ADS-B feed)? Do you get out your iPad or other device as you approach the airport? Do you look for traffic on an electronic display, rather than out your window? If you answered yes, then you are actually decreasing your chances of seeing and avoiding another aircraft.

You can mitigate this with proper preflight planning. Instead of looking up an airport diagram in flight, look it up and study it from the comfort of a pilot’s lounge before embarking on the flight. Plan your pattern entries and route of flight prior to flight. Modify your cockpit workflow to reduce your workload as you approach an airport. Run checklists prior to arrival in the airport traffic pattern as much as possible.

When you are in flight, keep your head outside, scanning small sections of sky. Use flight following or IFR services, because when ATC alerts you to another aircraft, your search is more effective than when no other services are used. And keep your eyes off that screen.

[1] See Administrator v. Harmon, NTSB Order No. EA-5493 (2009).

[2] Kunzi, Fabrice, and R John Hansman. “Mid-Air Collision Risk And Areas Of High Benefit For Traffic Alerting.” In 11th AIAA Aviation Technology, Integration, and Operations (ATIO) Conference, including the AIAA Balloon Systems Conference and 19th AIAA Lighter-Than. American Institute of Aeronautics and Astronautics, 2011.

[3] Limitations of the See-and-avoid Principle, Research Report, Australian Transport Safety Bureau. April 1991, reprinted November 2004.

Topics: Pilot Protection Services, AOPA Products and Services

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