Flight Training - December 2019 - 28

PREFLIGHT WHAT WOULD YOU DO?

DRIP DROP
WOULD IT BE FUELISH TO FLY?

YOU AND YOUR SPOUSE HAVE FLOWN

your Cessna 180 Skywagon to a rural airstrip, and you've stayed there for three days
to visit family. Now it's time to go home-
and you're more than ready to leave.
When you open the hangar door,
however, you notice the faint but unmistakable smell of avgas. Looking over your
Skywagon, there are several droplets
of blue avgas on the trailing edge of the
right wing.
You sump the right-wing fuel tank,
hoping that the sump drain is the source
of the fuel leak-but it's not. You climb

onto the wing and shine a flashlight into
and around the right fuel tank, hoping to
find the source of the drip-but it's not
obvious. You had filled both tanks shortly
after arriving at this airport, and now
the right tank has lost an estimated three
gallons of avgas.
You consult a local aircraft mechanic
on the field, and he suspects the tank
is cracked. Repairing it will involve
removing the tank from the airplane and
sending it to a weld shop, then reinstalling it. He estimates the entire process
will take two weeks.

It's a gorgeous day and you and your
spouse are only 90 minutes from home by
Skywagon. You can easily cover that distance using the fuel in the left wing only.
Do you:
1. Fly home on the fuel already in the
airplane?
2. Drain all the fuel out of the leaky
right tank and use the fuel in the left tank
to fly home?
3. Help the mechanic remove the
leaky right fuel tank from the wing and
send it out for repairs? You're driving
home.

GO FOR IT

DOOR NUMBER 2

IT'S WORTH THE REWARD

BE SENSIBLE

B Y D AV E H I R S C H M A N

B Y I A N J. T W O M B LY

I'M CHOOSING OPTION ONE: FLY HOME

AS WITH ANY DECISION INVOLVING THE

using the fuel already in the airplane.
The fuel leak is small, and it's
located in a place where it's not a fire
hazard. Prop blast will likely blow it
into the slipstream all the way home. I'll
select the intact left tank for takeoff and
climb, then switch to the right tank during
cruise to use up as much fuel as possible from the leaky tank
on the way home. The faulty tank is going to be sent out for
repairs as soon as we get home, anyway, and this will help
empty it.
This leak is an annoyance, and it could be costly to repair-
but it's not an immediate danger. If we only flew mechanically
perfect airplanes, we'd seldom get off the ground. Just about
every airplane at the flight school where I did my initial training had squawks, inoperative systems, and idiosyncrasies that
pilots were told about and worked around. This fuel leak is in
the same category. This Skywagon is nearly 60 years old and it
shows its age with leaks and creaks.
Would I make the same decision to fly if I wasn't desperate
to get away from my in-laws? Yes, I think I would. Aviation is a
constant balance of risk and reward. What's the benefit to any
course of action? What's the downside? Here, the risk seems
like it's worth the reward.

mechanical status of an airplane, there
are two questions you must answer
before deciding what to do: Is it safe,
and is it legal?
In this scenario, the second choice,
while not the safest, is practical and
reasonably safe. By draining the fuel we're
reducing the extremely low likelihood of fire, taking away any
risk of the fuel contaminating bits inside the wing we can't
see-and perhaps most important, being a steward of the environment. Avgas is nasty stuff. No need to throw it carelessly to
the wind.
The harder question to answer is one of legality. The pilot
in command is the only person who can determine if the
aircraft is airworthy for the flight. So, what is airworthy? The
definition says to be airworthy the aircraft must conform to
the type certificate and be in a safe condition for operation.
Which brings us back to the first question.
I think you could make a logical argument that with plenty
of fuel for the short flight in the other wing tank and no fuel
running overboard, safety is not compromised. That said, I
would have a long talk with the mechanic to get his or her
input, and possibly request the fuel selector be blocked from
the empty tank and a placard be added.

dave.hirschman@aopa.org

ian.twombly@aopa.org

28 FLIGHT TRAINING DECEMBER 2019

Flight Training - December 2019

Table of Contents for the Digital Edition of Flight Training - December 2019