AOPA Pilot Magazine - January 2021 - 22

SAFETY SPOTLIGHT

Near miss

BY RICHARD MCSPADDEN
Senior Vice President
AOPA Air Safety Institute

Analyzing midair collisions in GA

AOPA Air Safety
Institute Senior
Vice President
RICHARD
MCSPADDEN

is a CFII and MEI,
and has logged
more than 1,000
hours of dual
instruction given.

22 | AOPA PILOT January 2021

WE AVERAGE EIGHT midair collisions a year in general
aviation, two of them fatal-a relatively small number
compared to the 25 million or so flight hours and tens
of millions of flight operations in GA aircraft every year.
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.
AOPA
EMAIL richard.mcspadden@aopa.org

AOPA Pilot Magazine - January 2021

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