Avionics News May 2021 - 48

SAFETY IS NO ACCIDENT
Continued from page 47

It seems that we're getting some improvement from new
technologies, but not as much as anticipated when these
technologies emerged.
In another area where technology has provided more
help, 35 accidents during takeoff and climb occurred due
to loss of control, again a pilot-induced accident. Another
18 takeoff and climb accidents stemmed from the aircraft
stalling or settling back to the runway during the departure
attempt.
With more pilots using electronic flight bags, pilots have
access to graphics detailing runway length, field elevation
and near-live weather information that could help the
attentive pilot know the precise details of the airport being
used.
The vast majority of the takeoff and climb accidents - 76,
or 95% - occurred in VMC conditions, while two, equal
to 2.5% of these accidents, occurred in day instrument
meteorological conditions.
A total of 12 accidents occurred during the maneuvering
phase of the flights with two of those producing fatalities.
Loss of control, once again, underpinned the majority
of these events with nine due to loss of control or an
unintended stall. Of those, two produced fatalities.
Weather-data benefits
Seven accidents were attributed to weather encounters
- down from 42 in 2017 and 23 in 2018. Of the seven
accidents the report attributes to weather, three were
attributed to poor IFR-flight techniques and another three
from the most-avoidable cause of all: VFR flight into
IMC. The 2019 report attributed one weather-related
accident to turbulence.
Some flight-safety authorities attribute this welcome
decline to the wider availability of live or near-live incockpit weather information. The sources vary: ADS-B
In, subscription satellite weather, GPS navigators and
EFBs all provide an avenue to receiving live weather in
the cockpit.
The decline in accidents stemming from VFR into IMC
appears as another contributor to the decline.
With the availability of more weather graphics
than ever - on smartphones, tablets, dedicated EFBs
and displays on glass cockpit components - there's a
feeling that the reduction is at least partly attributable
to the increased awareness of conditions. All thanks to
continuing weather updates in-flight.
But with so many new ways to get and see weather
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avionics news

may

2021

conditions from miles away, a question remains: Are
pilots ignoring what they see, or are they seeing the
images without their meaning penetrating the pilot's
focus?
Focus, scan, refocus
Ever more of today's general aviation aircraft employ a
primary flight display instead of a six-pack of analog dials
for airspeed, altitude, vertical speed, turn rate, the gyro
compass or heading indicator, and the attitude indicator.
With the analog stack, each dial provides different
information.
While the PFD provides the same data, the presentation
differs dramatically. The altitude, vertical speed and
airspeed each presents as a vertical tape, with the airspeed
tape typically on the left side of the attitude indicator,
altitude flanking the AI on the right side, along with a
form of vertical-speed indication. The AI is dead center in
the display, with the heading indicator immediately above
or below the AI graphic.
The benefits to the pilot's need to scan are significant.
Instead of needing to scan between six different dials,
the pilot can see and take in all six instruments at once -
without as much head movement, a big help when flying
inside the eggshell of IMC.
But that benefit can still be thwarted by human fixation
on one indication. Or by missing an indication. Or by
what's called " expectation bias. "
When a pilot experiences expectation bias, it's because
the pilot sees or hears what experience taught the pilot
to expect to hear or see - as opposed to what actually
is happening. It's a phenomenon driven mostly by
experience or repetition.
It can happen when a pilot crosses a runway without
clearance because he or she regularly uses that field and
receives the clearance almost immediately - in most cases.
The potential for something to go wrong can be significant
by creating a potentially dangerous situation.
In a past issue of CALLBACK, the National Aeronautics
and Space Administration publication of reports filed with
the agency's Aviation Safety Reporting System, an airline
captain related a flight in which a strange rumble and
accompanying vibration caused both the captain and first
officer to focus on finding the cause.
In his report to ASRS, the captain wrote, " We were
focused on avoiding thunderstorms in the departure
corridor. Immediately after takeoff, we requested a right
turn from departure. We also remained vigilant of the
(reported traffic). There was now another concentrated
area of weather directly ahead. I was trying to break into

Avionics News May 2021

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