AOPA Turbine Pilot Magazine - September 2019 - 24

SAFETY SPOTLIGHT

BY RICHARD MCSPADDEN
Executive Director
AOPA Air Safety Institute

No easy answers
Why did an experienced pilot err so greatly?

RICHARD MCSPADDEN

led more than 100
flight performances
as commander
and flight leader of
the U.S. Air Force
Thunderbirds.

MOUNTAIN HOME, IDAHO. Completing an afterburner
takeoff with the U.S. Air Force Thunderbirds in diamond
formation, I pulled the four-ship high and left, behind
the crowd, then began a wide, descending 270-degree
turn to gather speed and manage timing to run-in for the
cloverloop airshow opener. Meanwhile, Thunderbird 5,
the lead solo pilot, performed his aileron roll on takeoff
and Thunderbird 6, the opposing solo, began a maximum-performance afterburner takeoff, to be followed
by a split-S maneuver down the showline-which runs
parallel to and 1,500 feet in front of the crowd line.
Floating the sweeping left turn back inbound, gathering speed, and with about 45 degrees remaining to
face show center, I heard Thunderbird 5's frantic voice
call "knock it off," the universal aviation call to cease all
maneuvering because of a dangerous situation. I echoed
the knock-it-off call, continued the turn perpendicular
to the show line, and faced a horrifying sight. Along the
show line, parallel to and directly in front of the crowd,
was a line of fire a couple of thousand feet long.
A linear crash line is a more fearsome sight to lowaltitude pilots than a single, smoking-hole impact. A
linear crash line usually means the pilot stayed with
the airplane and didn't get out. My heart sank. The fear
turned quickly to sorrow and deep grief at what was
certainly the loss of a beloved pilot. I knew his beautiful family well, and his two young children immediately
crossed my mind. What grief they soon would know.
I led the diamond formation over show center, crossed
the line of fire, and began a turn to orbit the crash site,
when one of the Thunderbirds made a call that remains
the most emotional radio call I'm likely to ever hear.
"Thunderbird 6 is standing, and waving at the crowd."
Ejecting less than a second before impact, well outside the ejection window and without time for a full
parachute deployment, Thunderbird 6 hit the soft Idaho
"moon dust" on a linear vector, directly in front of the
crowd, and tumbled to a stop with barely a scratch.
An Air Force investigation team found that
Thunderbird 6 miscalculated his altitude above the ground
and began the split-S maneuver some 800 feet below his
target apex altitude. The more difficult question, which
vexed the accident board, was: Why did an experienced
and disciplined pilot commit such a large miscalculation?
The investigators combed through hours of tape
from previous airshows and maneuvers. They found

24 | AOPA PILOT September 2019

remarkable discipline and consistency in Thunderbird
6. He never hedged his parameters and performed the
split-S maneuver with consistency in his apex altitudes
and speeds. The investigators settled on three factors that
led to the critical error, the most intriguing of which was
what they called a "preconscious level of awareness."
In essence, the investigators noted several indirect
influences that may have established a predisposition
toward subconscious error:
* High density altitude, which reduced aircraft performance and lengthened the time it took to climb to
the minimum altitude required to begin the split-S. In
Thunderbird 6's internal clock, it likely felt about the right
time to roll inverted and pull, and when he checked his
altimeter, he saw what he expected, not what was displayed.
* Comments I had made as leader in the preflight briefing about this show at 3,000 feet msl feeling more like
our home field-Nellis Air Force Base in Las Vegas,
Nevada, at 2,000 feet msl-than our previous day's show
in Reno, at 5,000 feet msl, may have influenced the altitude numbers in 6's subconscious.
* The egregious requirement for Thunderbird pilots to
perform mental calculations on exact agl altitudes. While
inverted in a split-S maneuver, Thunderbird 6's focus on
the math likely distracted from his focus and contributed
to him misreading the conspicuous altimeter read-out.
* Fatigue, mentioned as likely, since the team was on the
home stretch of a long show season that began in March.
The investigators struggled to explain why a talented
and disciplined pilot made such an error on a maneuver
he'd performed hundreds of times with an impressive degree of consistency. There was no smoking gun.
Somehow, it seems, a lot of little things added up and in
the flash of a moment, a near-fatal mistake was made.
One of the many lessons from that September day
is how quickly aviation can turn from routine to disastrous. Our subconscious is constantly working: assessing,
calculating, making decisions, usually in our favor. But
it is imperfect, and when the stakes are high, we need
redundant methods to confirm decisions with critical
implications. Such decisions are made every time we fly.
Go fly. Keep an eye on the influences to your subconscious, and the resulting actions, which could drastically
change the outcome of your flight.
AOPA
EMAIL richard.mcspadden@aopa.org

AOPA Turbine Pilot Magazine - September 2019

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