AOPA Pilot Magazine - January 2024 - 106

FLY WITH AOPA
ASI SAFET Y TIPS /
Reasons for the runup
The critical checks every pilot should master
BY TERRIE MEAD
Engine instruments: We monitor
engine instruments, such as oil pressure,
oil temperature, and fuel flow, to verify
they're within specified parameters and
that there are no indications of system
anomalies.
Ammeter and electrical system: By
observing the ammeter at increased rpm,
we can ensure the electrical charging system
works correctly and that there aren't
any unusual electrical loads or shorts.
System anomalies detection:
Besides the specific checks, the runup
allows you to detect abnormal noises,
vibrations, or smells that might suggest
a problem.
Throttle to idle: When we throttle
MECHAN I CA L FA I LURE ACCOUNTS for
about 20 percent of all airplane accidents.
How can we avoid landing among those
counted in that statistic?
Crucial to any preflight is the series of
tasks performed in designated runup areas,
a feature of almost all airports. The runup is
so essential to safe flight that airports have
set aside precious real estate for just these
few steps on our preflight checklist.
Here are the typical runup tasks and
their purpose:
Engine health check: The engine is
brought to a specific rpm on the ground to
ensure smooth and consistent operation
at altitude. This can help detect irregularities
potentially indicating fouled spark
plugs or other engine malfunctions.
Magnetos: We switch between magnetos
during the runup to ensure each
operates correctly without a significant
rpm drop. A decrease greater than 200
rpm could indicate a magneto timing
problem that should be checked, or other
problem with the ignition system.
106
AOPA PILOT / January 2024
Propeller control: Runup for aircraft
with adjustable propellers means cycling
the prop to check pitch change and oil system
integrity. Verify oil pressure is in the
green range and oil temperature is climbing
to the green-vital in cold weather to
prevent overspeed.
Carburetor heat: For carbureted
engines, pull the carb heat on for at least
10 seconds during the runup, and watch
for the expected slight dip in rpm. A drop
exceeding 300 rpm indicates an exhaust
leak, and flying with a suspected leak is
unsafe.
Brake reliability: Holding the
brakes during the runup verifies brake
effectiveness.
Suction gauge: The suction gauge
indicates the pressure produced by the
vacuum pump and can reveal the vacuum
system's overall health. This check can
confirm the suction is within limits. If it
reads too low, the suction drawn through
the gyroscopes may be insufficient to keep
them stable.
all the way back from our runup rpm,
we mimic the power change we initiate
during the landing phase, allowing
us to make sure the engine is running
smoothly at idle.
Meticulous preflight runups are
more than routine; they're our gateway
to safe skies. Such diligence fortifies our
defenses against in-flight failures, reaffirming
the runup's critical place in our
safety arsenal.
terrie.mead@aopa.org
airsafetyinstitute.org
New from ASI
In the heat of the moment
In the latest video, Real Pilot
Story: The Heat of the Moment,
a couple shares lessons learned
and the circumstances that led to
an accident shortly after takeoff
from a backcountry airstrip in
Arkansas.
airsafetyinstitute.org/RPS/
HeatOfTheMoment
http://www.airsafetyinstitute.org http://www.airsafetyinstitute.org/RPS/HeatOftheMoment http://www.airsafetyinstitute.org/RPS/HeatOftheMoment
AOPA Pilot Magazine - January 2024

Table of Contents for the Digital Edition of AOPA Pilot Magazine - January 2024
