Safety Spotlight: Near miss

The troubling news is the annual average appears stagnant and we have a worrisome number of near misses. Our training in visual scans, radio use, and procedures in cruise and the traffic pattern have helped to make midairs rare, but we can make them extinct and reduce the number of close calls. We’ll need to capitalize on new technologies, such as ADS-B; learn how and when to use them most effectively; recommit to discipline on established procedures; and utilize new techniques when appropriate to drive midairs to zero.

The AOPA Air Safety Institute analyzed midair collisions and determined that collisions in cruise, especially a near-head-on collision, are exceptionally rare. More likely, the impact in cruise will occur converging from the side, and the highest probability of an impact in cruise will occur with one aircraft overtaking the other.

The greatest risk of a midair collision appears to be in or near the traffic pattern. Airplanes converging to the same relative point in the sky are more likely to create conflicts as the “big sky” gets squeezed. Most midair collisions happen within five miles of an airport.

After a troubling 18-month period in Alaska that included a few tragic midair collisions, ASI initiated a survey last October among Alaskan pilots to determine the extent of near misses in the region. We defined near miss as “flying in close proximity to an aircraft you weren’t aware of or that caused you to take immediate evasive action to avoid a collision.” Some 710 pilots took the survey, almost 50 percent of whom reported a near miss in the past five years, and 25 percent of whom had multiple near-miss events. In spite of recent advancements in technology, the respondents reported 719 near-miss events in the past five years. Thirty-six percent of them happened within the past year. Survey participation represents 11 percent of the 6,597 pilots registered in Alaska. Clearly, traffic spotting, avoidance, and deconfliction are critical skills to Alaskan pilots.

Forty-seven percent of the Alaskan pilots involved in a near miss listed communications as the contributing factor: lack of communication; frequency congestion; and confusing, or nonstandard, terminology. Alaskan pilots overwhelmingly believed that ADS-B could play a better role in preventing near-misses. Half of respondents were ADS-B equipped. ADS-B coverage is a sensitive issue. Because of the mountainous terrain and large expanse, complete ADS-B coverage in Alaska doesn’t exist and is expensive to implement. The FAA plans additional ground stations, which will help ADS-B adoption, but full coverage isn’t in any near-term plans.

Some suggest we can reduce the potential for midair collision by adding more randomness in our altitude selections. Their analysis adds credibility to a thought I’ve had while cruising VFR. With proliferation of GPS, autopilots, and digital displays, we are all flying more precisely than ever before with instrumentation that’s more accurate. Variances in system tolerances, analog displays, and interpretations are disappearing, resulting in smaller altitude and course discrepancies. More pilots are flying exactly on course, exactly on altitude.

FARs 91.159 and 91.179 dictate our cruising altitude options. Even though cruise midairs are rare, perhaps we can tilt the scales in our favor by flying random, atypical altitudes when we’re below 3,000 feet agl. Often, when I’m on VFR flight following, I’ll advise the controller that I’ll hold an unusual cruise altitude, like 4,700 feet. They typically acknowledge and advise with that soothing phrase: “Maintain VFR, altitude at your discretion.” I usually take comfort that there’s not likely anyone else cruising at an unusual altitude like 4,700 feet.

Midair collisions should become extinct. As with almost all things in aviation, making them extinct will depend on pilots. Adopting new technologies like ADS-B and maintaining proficiency in using them will help. Even small advancements such as brighter and pulsating lights that grab the eye will reduce collisions. Making adjustments like unusual cruise altitudes where allowed may create some needed space. We can make the most impact through vigilance in known areas of congestion, such as the traffic pattern. We can strengthen our discipline to depart or approach each airfield with all lights on; using standard procedures; clear, crisp transmissions; and listening actively. Inbound, as we approach the pattern, we should commit to conclude all of our inside tasks and adopt an eyes-out posture, utilizing our passengers if appropriate, knowing that we are about to enter the highest-risk arena for midair potential.

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