AOPA Pilot Magazine - May 2018 - 87

IN MY YOUNGER DAYS while I was studying
for an upcoming checkride, an old-timer
walked into to the room and said, "Hey
Markus, it's all very simple: Fly the helicopter and don't hit anything." He smiled,
walking out of the room while I muttered
under my breath: Tell that to the check airman expecting me to execute emergency
procedures perfectly and recite countless
limitations.
Helicopters have a higher risk for wire
strikes because of the way they are flown.
A helicopter's unique capabilities lend it to
the type of work often requiring low-level
flight over unknown terrain, such as picking
up an accident victim or slinging buckets of
water to fight a fire. Wire and object strikes
comprise the top operational cause of fatal
helicopter accidents, and it's a sobering
thought to know that two fatalities occur for
every five wire strikes. Studies have shown
that although flight experience can lower
risk in many aspects of flight, there is no
statistical difference regarding wire strikes
between high-time and low-time pilots.
Wires are hard for everyone to see.
Back in the 1980s flying power line
patrol, you would think I would have been
a wire avoidance expert, flying about 1,500
hours a year at an altitude no higher than
300 feet. But just as the data show, experience is not an asset for avoiding a wire
strike-which I almost proved one day.
A local TV station was doing a feature about flying helicopters on power
line patrol, and I had just landed in a small
field to meet them. There were no hazards,
except for a small telephone wire at the
opposite end of my approach. An hour later
the cameraman asked me to depart in the
other direction from the approach, and it
was during takeoff I suddenly remembered
that little wire. Instantly adding more
power with an aggressive cyclic climb, I
finally saw the wire zipping underneath
about five feet, followed by a man that was
stupid, I'll never do that again moment. I
had changed my planned departure path
without careful thought and another
reconnaissance of that area.
Techniques helicopter pilots use to avoid
wire strikes include thoroughly assessing
an area from a higher altitude, realizing the
wires not seen are most dangerous. Scan for

easier-to-see poles and towers, and don't
assume there aren't extra wires splitting
off in a different direction. Try to make the
departure path the same as the approach
path; no hazards on approach dictates you
should be clear on departure. The more eyes
the better, so use people onboard, having all
crew and passengers with "eyes outside"
looking for any hazards. Private helipads
should be treated as carefully as off-airport
areas, as they do not offer the same assurances as public helipads or airports. Wires
adjacent to a private helipad do not require
marker balls, nor do towers less than 200
feet have to be lighted. Picture landing at
an unfamiliar hospital helipad at night, with
an unlighted 190-foot communication tower
250 feet away.
Helicopter terrain avoidance warning systems and sectional charts, while
useful for en route flight at safe operating
altitudes, can be of limited use when operating low level as obstacles lower than 200
feet are not included in the database. A
safe en route altitude is dependent on the
area flown, but many would consider 500
feet to be a minimum for onshore daylight
conditions. Avoid "getting squeezed"-
deteriorating weather can reduce the
available altitude, resulting in a lower cruising altitude and increasing the risk for a
wire strike. Power line detection systems
are effective but only detect energized lines.
Support wires, guide wires, zip lines, ropes,
and some tramlines are not energized and
so do not produce an electromagnetic field
that can be detected. A wire strike protection system, which typically can cut a
steel cable up to three-quarters of an inch,
also has its limitations. It doesn't provide 100-percent frontal coverage, and it's
dependent on the helicopter flying at least
30 knots at no less than a 60-degree angle to
the wires with no more than plus or minus
5 degrees pitch attitude. All these systems
certainly lower the risk of a wire strike, but
the best wire strike deterrent is the pilot.
It isn't the wires you see that will kill
you, but the ones you don't see.
AOPA

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MARKUS LAVENSON is a captain in the

Sikorsky S-92 and Leonardo Helicopters
AW139 flying oil and gas support missions
in Alaska and the Gulf of Mexico.

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AOPA Pilot Magazine - May 2018

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