Flight Training - November/December 2024 - 43

If the engine acts up, ensure the magnetos are set to
Both, unless the engine is shaking like a wet dog-this
could be a sign of a mag misfiring, and you can quickly
isolate the bad one and shut it down using that " rightleft-both "
control.
There are times, although rare, when engines
mechanically fail. You might recall being told that your
engine is " direct drive, " meaning the propeller is bolted
directly onto the crankshaft with no transmission. In
flight, if an engine fails, the prop will windmill in the
relative wind, so long as the crankshaft can turn. In a
GA airplane with a fixed-pitch propeller, if the prop
stops moving in flight, something terrible has happened-mechanically-to
keep the crankshaft from
moving. That's not a fuel-air-spark problem
and it's time to choose an emergency
landing spot.
A solid understanding of the
powerplant cooling system is also
worthwhile. Most of our engines
are air-cooled, with the cowl dividing
the engine compartment into
two halves. The system is set up so
that the top half is slightly higher
pressure and air flows uniformly
down the cylinder fins to the bottom
of the compartment. If you are seeing an
increase in engine temperatures, check the baffling
for holes or damage. An air-cooled engine also gets a
lot of its cooling from the circulation of oil, so oil temperature,
oil pressure, and cylinder head temperatures
tend to correlate and can serve as cross checks on each
other. Steadily dropping oil pressure with rising oil
and engine temperatures could suggest an oil leak, and
that demands a quick landing.
ELECTRIFYING KNOWLEDGE
The number one thing you need to understand about
the electrical system as a pilot is that you don't need it.
The airplane will fly just fine if it fails.
So, then, what does the electrical system do? It
powers your com radios, nav radios, the intercom, and
your transponder as well as your lighting system. In
some airplanes the wing flaps are electric. Likewise,
some trim systems are electric. If you have a " switch
on " backup fuel pump, it's probably electrical too.
The list goes on: pitot heat and some deicing and
anti-icing equipment; autopilot and landing gear (if
equipped); and depending on your aircraft, your flight
instruments may be electric. Of course, all glass-panel
avionics are electrical. In a traditional analog setup, it's
possible that all three gyroscopic flight instruments-
the attitude indicator, heading indicator, and turn
coordinator-are powered electrically.
That's a lot of powered stuff that will start sucking
your battery dry the second after an alternator/generator
failure. The trick in such a case is immediately
prioritizing what you need and shutting down everything
else to preserve battery life. If you are VFR on a
lovely day and know where you are, shut it all down
and fly the airplane. When you get close to the airport
you were heading to, power up your radios and any
other items you need to land safely.
In the case of an electrical fire, an understanding of
how your electrical system is divided and segmented
can help you isolate the affected circuit. Think about
the journey of the electron in a similar way to the journey
of our fuel molecule. How does your ship make
electricity and how does it use and store it?
Any airplane that has an electrical system has at
least one battery. That's where the commonalities
end. Older airplanes have generators
to make electricity, and they don't put
out much power at low rpm. Also, the
generator systems tend to directly
feed the battery, while the battery
itself directly powers the airplane. If
the airplane sucks more power out
of the battery than the generator is
producing, things will shut down. In
newer alternator-powered airplanes,
the alternator most often powers the ship
directly while topping off the battery as a side
job. In this kind of setup, the battery really only comes
into play for starting and for emergency power if the
alternator fails. Such airplanes commonly feature a
split master switch, allowing the pilot to shunt the
power supply from the alternator to the battery.
The electrical delivery system involves switches,
buses, and circuit breakers or, in older airplanes,
fuses. Working backward, circuit breakers provide
overload protection for individual circuits. In some
airplanes there are lots of circuit breakers, seemingly
one for each electrical device in the airplane, in other
airplanes only a few. It's handy to have an understanding
of which electrical appliances are plugged into the
various circuits. Buses are like power strips and can be
used to create primary and secondary power systems.
Switches can let you further isolate individual components
or systems and are also handy for shutting
down less-critical devices in an alternator or generator
failure to maximize battery life. The older the batteries
are, the less charge they hold. Don't expect to get
whatever number of minutes the manual says you'll
get unless you just got a new battery.
The health of your alternator or generator can be
monitored in multiple ways, depending on how your
airplane is equipped. Many have a warning light on
the panel-include that light in your normal scan. In
a glass cockpit airplane with digital instruments, you
will likely get a caution or warning message. For the
rest of the pack, your go-to indicators are a variety of
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Flight Training - November/December 2024

Table of Contents for the Digital Edition of Flight Training - November/December 2024
