Flight Training - May 2015 - 26

FLIGHT LESSON

By David Peterson
FLIGHT LESSON offers the
opportunity for pilots to learn
from the experiences of others.

A WHIFF OF FUEL

AN INADEQUATE PREFLIGHT INSPECTION

O

n the checkride for my private pilot certificate 20 years ago,
the examiner handed me a temporary certificate and said,
"Here's your ticket to learn." Those words have stayed with
me over the years and have proved true on many occasions.

I had just purchased my very own
warbird, a 1954 Yakovlev Yak-18, in Las
Vegas, Nevada. A beautiful sunny Sunday
morning was all the invitation I needed to
take the new airplane up for a flight.
On the way to my hangar I ran into
my friend Jim, who was about to fly his
North American AT-6 up to Reno for the
National Championship Air Races. He
suggested that if I could quickly get my

access panel that covers the fuel cap.
Jim was about five minutes from
engine start, so I figured I could get airborne first and loiter near the field. The
takeoff was typical except that, on the
downwind leg, there was a faint smell of
avgas in the cockpit. Having over-fueled
the aircraft previously, I surmised that
some gas had spilled into the tank bays
and it would dissipate shortly. I climbed

HAVING OVER-FUELED THE AIRCRAFT
PREVIOUSLY, I SURMISED THAT SOME GAS
HAD SPILLED INTO THE TANK BAYS AND IT
WOULD DISSIPATE SHORTLY.

26 /

FLIGHTTRAINING.AOPA.ORG

to 4,000 feet and circled about four miles
north of the airport while waiting for Jim.
Jim took off and I joined up on his
port wing for some formation practice.
At this point, the fuel odor became more
noticeable. I scanned the instruments
and saw nothing out of the ordinary. I
glanced at the wing fuel gauges and fuel
access panels and saw nothing alarming.
The odor was very strong now. I told Jim
I had a minor problem and needed to

ALEX WILLIAMSON

Yak-18 airborne we could fly formation for
part of the trip to Reno.
I called the fuel truck and headed over
to my hangar. I removed the fuel access
covers and fuel caps from both of the
Yak's fuel tanks. About 10 minutes later,
the lineman had topped off the tanks, and
as I was sealing the port tank, he said, "I
already got the starboard tank for you."
I thanked him and went over to
the starboard wing and installed the

return to the airport. I bid him good luck
and turned back. Calling the tower at four
miles out I was cleared for Runway 25L. I
didn't declare an emergency as the pattern
was empty and the problem did not seem
severe.
On final approach the smell of avgas
became overpowering. To compensate I
opened the sliding canopy. I immediately
felt droplets of fuel hitting the back of my
head and saw them whisking out the open
canopy. I quickly put the airplane on the
runway, and as it slowed down the fuel
smell dissipated.
I taxied back to my hangar. As I turned
the corner to my hangar row I looked back
to see a trail of fluid along the taxiway. I
shut down the engine and could hear gas
dribbling out of the belly of the aircraft. I
climbed out and found about half a gallon
of gas was pooled beneath the rear seat.
I wondered if I had somehow ruptured
a fuel tank. Then I opened the fuel cap
access panels to inspect the fuel caps and
tanks. When I opened the port panel,
everything was in order and the cap was
on tight. When I opened the starboard
panel I saw the culprit: the starboard cap
was not fastened. The low pressure inside
the wing had lifted the cap up and allowed
fuel to siphon out of the tank, then flow
into the center section before the vapors
(and gas droplets) were drawn forward to
the front of the cockpit. Apparently when
the lineman had fueled the aircraft, he had
placed the cap in its receptacle but had
not locked it in place. About five gallons of
fuel had been siphoned out of the tank.
I stared at the loose cap for a very, very
long time and thought about how close I
had come to a bad situation. I also thought
about the National Transportation Safety
Board report's conclusion if it had been
far worse: "Probable cause: The pilot's
inadequate preflight inspection...."
Since then I never let anyone else
secure the fuel caps, and I always check
them before every flight.
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Flight Training - May 2015

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