Jeff Francis sent this photo of a metal spinner that was
bent by departing propeller blades. Drilling or modifying
propellers can be dangerous.
straight up approximately 50 feet. Each
piece had quite a bit of force and if
someone had been in line with the prop
disk, it could have really hurt them.”
Propeller alterations are almost always
a bad idea, as Jeff now knows. It’s worth
the cost of a new airscrew every time,
because when they fail, they usually
fail badly. I’ve seen some wise pilots
deliberately break a worn propeller in
half before throwing it away to prevent
some cheapskate from fishing the thing
out of the bin and using it.
A Serious Incident
My friend, Richard Cox,
knows more about electronics
than I ever will, but that’s not
why he emailed me. Richard
wanted to report an incident at
a local club, from which we can
all learn. No names or locations
on this one—just the facts.
“A pilot was sharing his
electric plane with another
person and the model was
armed and ready to fly. The
throttle was somehow bumped
while the pilot’s hand was in the
rotational area of the propeller.
The prop sliced into his wrist,
creating severe bleeding.
“Fortunately, there were others
at the field to provide medical
aid. The wound was so serious that a
tourniquet had to be applied to control
blood loss until emergency treatment
could be rendered at the hospital.
“This was considered a major incident.
Thanks to prompt and skillful first-aid
treatment, the pilot made it through
emergency surgery and was released to
This was a classic propeller-strike
mishap. A club report on the incident
had several suggestions, and of course,
the main one was to keep your mitts out
of the propeller disc, even when it isn’t
Our newfangled electric power
systems can go from off to full bore in a
millisecond, and they don’t care who or
what is in the way.
The report also mentioned the
importance of programming the
transmitter with a throttle-cut switch
that can be activated when the airplane
is not ready to fly on the taxiway or
runway. Otherwise, the battery should
be disconnected when not flying.
The club reinforced that pilots should
not fly alone. With no one to render aid,
the flier in this story might not have
Flying alone is a bad idea, and is not as
much fun as having your pals around to
see you goof your landing.
99 Model Aviation DECEMBER 2015