thrust caused the plane to rotate in my fingers
sufficient to allow the propeller to lacerate my
lower arm.
“Lots of blood everywhere. Luckily, my
wife was with me and drove me to a nearby
emergency room where I received a dozen
stitches. Interestingly, I suffered no pain
during the incident, and had no idea that I’d
been cut so deeply.”
Tom had several lucky breaks on this one,
not the least of which was to have someone
with him at the field. My wife, sweet Diedra,
would have cauterized the wound for me on
the spot with a few choice comments.
Tom’s calm spouse helped him
greatly, but I’ll bet she thinks twice
about going flying with him next
time.
This incident is a classic, because
it reminds us of several important
safety points. As with Tom and me,
many pilots require adult supervision,
so “bring a friend” is a good rule.
You might end up as the helper or the
helpee, but don’t fly alone.
Electric systems can come to life
instantly, and at the most
inconvenient moment. This is tough
for old gas-power fliers to remember.
Those engines do not start
themselves, so the propeller arc is not
a hazard until the engine is roaring.
Not anymore!
A motor can respond to throttlestick
movement anytime the
system is “live.” Many modelers
use arming keys or switches to
avoid accidents such as Tom’s.
There are pros and cons to having
a cutoff feature, but the photo of
Dave Gee | Safety Comes First [email protected]
Propeller-strike injury cuts into a reader’s flying time
A propeller arc is dangerous, even if the motor is off. Tom Chytil
bumped this model’s transmitter and away it went.
Dawson Gillaspy uses plastic spacers and long screws as motor
mounts. They’re sturdy and work fine for him.
This airplane is flying with an antique compressed-air power system. Bud Matthews was
optimistic enough to add a DT.
Also included in this column:
• Eye protection: in your face
again
• Compressed-air power: the
latest in 1880s technology
• Buddy boxes connected to
trouble
• Innovative motor mounts
I LIKE TO start each column with a
“grabber,” and Tom Chytil sent in a
humdinger. His electric-powered RC foam
model has had an eventful history.
It was originally a high-winged version
that was treed twice and badly damaged
during recovery. Tom rebuilt the aircraft as a
midwinger, and the airplane repaid him by
slicing his arm open like a warm bagel.
Tom takes some of the blame, noting that
the model has no will of its own, but I’m not
so sure. He wrote:
“I was at the flying field holding the plane
as shown, walking it a few steps to the takeoff
area. Everything was live. The transmitter
brushed against my leg and knocked the
throttle up to about 30% power. The propeller
76 MODEL AVIATION
03sig3.QXD_00MSTRPG.QXD 1/25/10 1:24 PM Page 76
his arm is a good argument in its favor.
Another point fits in with an e-mail
exchange I had with Scott O’Connor. He is an
experienced RC pilot and a wise man, and he
asked me to stress the concept of propeller-arc
exposure. It seems obvious enough to beware
of inserting body parts into its direct path, but
people do it all the time.
Brightly colored propeller tips and other
aids might help, but a distracted moment and
inadvertent movement are too easy to
experience. Scott went beyond this thought
and asked me to mention keeping awareness
of the arc beyond the actual airscrew.
Most pilots have seen a broken propeller
or rotor sometime. The danger zone for
broken pieces is in the extended disc of the
propeller, so it makes sense to stay out of that
area whenever possible.
When a propeller blade separates or
breaks, the pieces will fly out in a straight line
along the projected propeller arc. Minimize
your exposure in this projected extension of
the propeller by placing your body ahead of or
behind it while servicing your airplane.
Helicopter pilots have a tougher time
with this, since half of their rotors are
horizontal, but they can still arrange for the
minimal exposure possible.
Scott also mentioned the importance of
using proper eye protection. I’m with him
all the way on that point! Getting an arm
stitched up is bad enough, but losing sight
is much more serious to a model-aircraft
pilot.
I often plug Zurich sunglasses, because
their impact-resistant wraparounds are my
favorite. No matter how vigilant we are at
the field, some piece of fast-moving debris
might find us. Please get in the habit of
wearing appropriate eye protection!
Zurich International is a frequent
advertiser in this magazine, but there are other
excellent products available. I urge you to
consider making safety-rated glasses a part of
your outfit at the field as well as in your shop.
How about something really old school that
requires eye protection? Before electric
power, before even gas power, there was
compressed air (CA). This quiet and
challenging power system is experiencing a
small resurgence among the Old-Timer
crowd.
CA models have to be extremely well
designed to fly. Extra weight is a killer, since
the setup requires a large propeller, fairly
heavy motor, and a giant onboard pressure
vessel to hold the “fuel.”
CA pilots are mindful of what can happen
when an ultralightweight tank is filled with
enough pressure to operate an aircraft motor.
Take a look at Tony Naccarato’s photo of Bud
Matthew’s airplane chugging overhead.
The model uses a borrowed motor and
tank, both of which are antiques. Bud had to
repair several leaks in the tank using oldfashioned
solder on the paper-thin brass tank
body.
Some airplanes carry their pressurized
power in modern soda bottles. This lacks the
historical appearance and romance of the old
tanks, but avoids sending near-priceless
artifacts into the sky on an FF model. Those
pop bottles can really “pop” sometimes, so
eye protection is a must when using any CA
rig.
I think that the new Air Hogs flying toys
are partly to blame for the resurgence of CA
flight. These inexpensive airplanes and
helicopters are ready to fly, and boy do they
fly! Their motors are small for transplanting
into serious models, but some designers make
good use of them.
My friend, Ken Johnson, has flown and
had published some neat models that use
commercial motors. There is not much
tinkering or souping up possible on these
molded-plastic expansion motors, unlike the
classic handmade systems that can be tuned
and altered as the builder sees fit.
Old how-to books make it look easy to
slap a CA motor together. Ha! Fitting and
soldering brass takes practice and skill,
especially if your project is going to safely
handle a powerful supply of compressed air.
This is one reason why the old motors are still
in active use. Whether you try a new or old
CA power plant, wear your safety glasses!
I read yet another Internet discussion about
buddy-box systems that shoot down models.
It’s tough to get the word out to every pilot,
so I’ll write a reminder.
There have been conflicting reports about
which brands and models of radios are
involved, but it is possible to rig two
transmitters with a buddy cord for training or
First Person View (FPV) flying and
inadvertently send radio signals from the
second transmitter. This apparently happens
when a brand of cord other than the radio
brand is used to connect the two boxes.
Because there have been conflicting
reports, I recommend that only a matching
brand of connection cable be used, and it is a
wise precaution to remove the crystals from
the second radio during buddy-box use.
Want to know the future? There is a
wireless buddy-box system being tested,
using some sort of Bluetooth technology.
More than one student can be online, and
there are other keen features. Watch the
appropriate MA columns for details on this
product.
My recent plea for wisdom about electricpower
motor mounts brought in some great email.
Dawson Gillaspy of Long Neck,
Delaware, flies with the Lewes RC Club, but
he has been building models since long before
there was radio control or electric power.
He sent a photo of an unusual method of
mounting a motor to the firewall. He uses
sturdy plastic spacers and says that he has not
had problems with side-load failures.
Dawson wrote:
“The spacers stay perpendicular to the
firewall by the precision molded flat ends,
and the long 6/32-inch screws are held by blind
nuts. If the battery is located near or against
the firewall, it is important that the screw ends
do not protrude beyond the flange of the blind
nuts and allow the battery to impale itself on
the screw ends in a hard landing.
“I’ve used this system in 5-6 different
planes, large and small, and have never
experienced any distortion so I’m
comfortable with that method.”
I was concerned about how this setup
looked. It appears not to be rigid and looks
vulnerable to flexing sideways under the Gforces
of flight maneuvers.
Dawson assured me that the spacers and
screws are oversized and overengineered
for strength, and that is what allows this
system to deal with the stress of flight.
When a guy with that much experience
talks, I listen.
Concerning getting good advice, I
appreciate and enjoy answering the e-mail
and letters I receive. If you have a brilliant
idea or a close-call story, please share it.
Anonymity is available for those such as
me, who are embarrassed by their
occasional lapses of judgment. I should be
used to it by now.
Please put “MA” in your e-mail title so
my spam filter separates you from the fake-
Rolex watch ads. MA
Sources:
Dave Gee
Box 7081
Van Nuys CA 91409
Zurich Sunglasses
(916) 691-6467
www.zurichsunglasses.com
Edition: Model Aviation - 2010/03
Page Numbers: 76,78,80
Edition: Model Aviation - 2010/03
Page Numbers: 76,78,80
thrust caused the plane to rotate in my fingers
sufficient to allow the propeller to lacerate my
lower arm.
“Lots of blood everywhere. Luckily, my
wife was with me and drove me to a nearby
emergency room where I received a dozen
stitches. Interestingly, I suffered no pain
during the incident, and had no idea that I’d
been cut so deeply.”
Tom had several lucky breaks on this one,
not the least of which was to have someone
with him at the field. My wife, sweet Diedra,
would have cauterized the wound for me on
the spot with a few choice comments.
Tom’s calm spouse helped him
greatly, but I’ll bet she thinks twice
about going flying with him next
time.
This incident is a classic, because
it reminds us of several important
safety points. As with Tom and me,
many pilots require adult supervision,
so “bring a friend” is a good rule.
You might end up as the helper or the
helpee, but don’t fly alone.
Electric systems can come to life
instantly, and at the most
inconvenient moment. This is tough
for old gas-power fliers to remember.
Those engines do not start
themselves, so the propeller arc is not
a hazard until the engine is roaring.
Not anymore!
A motor can respond to throttlestick
movement anytime the
system is “live.” Many modelers
use arming keys or switches to
avoid accidents such as Tom’s.
There are pros and cons to having
a cutoff feature, but the photo of
Dave Gee | Safety Comes First [email protected]
Propeller-strike injury cuts into a reader’s flying time
A propeller arc is dangerous, even if the motor is off. Tom Chytil
bumped this model’s transmitter and away it went.
Dawson Gillaspy uses plastic spacers and long screws as motor
mounts. They’re sturdy and work fine for him.
This airplane is flying with an antique compressed-air power system. Bud Matthews was
optimistic enough to add a DT.
Also included in this column:
• Eye protection: in your face
again
• Compressed-air power: the
latest in 1880s technology
• Buddy boxes connected to
trouble
• Innovative motor mounts
I LIKE TO start each column with a
“grabber,” and Tom Chytil sent in a
humdinger. His electric-powered RC foam
model has had an eventful history.
It was originally a high-winged version
that was treed twice and badly damaged
during recovery. Tom rebuilt the aircraft as a
midwinger, and the airplane repaid him by
slicing his arm open like a warm bagel.
Tom takes some of the blame, noting that
the model has no will of its own, but I’m not
so sure. He wrote:
“I was at the flying field holding the plane
as shown, walking it a few steps to the takeoff
area. Everything was live. The transmitter
brushed against my leg and knocked the
throttle up to about 30% power. The propeller
76 MODEL AVIATION
03sig3.QXD_00MSTRPG.QXD 1/25/10 1:24 PM Page 76
his arm is a good argument in its favor.
Another point fits in with an e-mail
exchange I had with Scott O’Connor. He is an
experienced RC pilot and a wise man, and he
asked me to stress the concept of propeller-arc
exposure. It seems obvious enough to beware
of inserting body parts into its direct path, but
people do it all the time.
Brightly colored propeller tips and other
aids might help, but a distracted moment and
inadvertent movement are too easy to
experience. Scott went beyond this thought
and asked me to mention keeping awareness
of the arc beyond the actual airscrew.
Most pilots have seen a broken propeller
or rotor sometime. The danger zone for
broken pieces is in the extended disc of the
propeller, so it makes sense to stay out of that
area whenever possible.
When a propeller blade separates or
breaks, the pieces will fly out in a straight line
along the projected propeller arc. Minimize
your exposure in this projected extension of
the propeller by placing your body ahead of or
behind it while servicing your airplane.
Helicopter pilots have a tougher time
with this, since half of their rotors are
horizontal, but they can still arrange for the
minimal exposure possible.
Scott also mentioned the importance of
using proper eye protection. I’m with him
all the way on that point! Getting an arm
stitched up is bad enough, but losing sight
is much more serious to a model-aircraft
pilot.
I often plug Zurich sunglasses, because
their impact-resistant wraparounds are my
favorite. No matter how vigilant we are at
the field, some piece of fast-moving debris
might find us. Please get in the habit of
wearing appropriate eye protection!
Zurich International is a frequent
advertiser in this magazine, but there are other
excellent products available. I urge you to
consider making safety-rated glasses a part of
your outfit at the field as well as in your shop.
How about something really old school that
requires eye protection? Before electric
power, before even gas power, there was
compressed air (CA). This quiet and
challenging power system is experiencing a
small resurgence among the Old-Timer
crowd.
CA models have to be extremely well
designed to fly. Extra weight is a killer, since
the setup requires a large propeller, fairly
heavy motor, and a giant onboard pressure
vessel to hold the “fuel.”
CA pilots are mindful of what can happen
when an ultralightweight tank is filled with
enough pressure to operate an aircraft motor.
Take a look at Tony Naccarato’s photo of Bud
Matthew’s airplane chugging overhead.
The model uses a borrowed motor and
tank, both of which are antiques. Bud had to
repair several leaks in the tank using oldfashioned
solder on the paper-thin brass tank
body.
Some airplanes carry their pressurized
power in modern soda bottles. This lacks the
historical appearance and romance of the old
tanks, but avoids sending near-priceless
artifacts into the sky on an FF model. Those
pop bottles can really “pop” sometimes, so
eye protection is a must when using any CA
rig.
I think that the new Air Hogs flying toys
are partly to blame for the resurgence of CA
flight. These inexpensive airplanes and
helicopters are ready to fly, and boy do they
fly! Their motors are small for transplanting
into serious models, but some designers make
good use of them.
My friend, Ken Johnson, has flown and
had published some neat models that use
commercial motors. There is not much
tinkering or souping up possible on these
molded-plastic expansion motors, unlike the
classic handmade systems that can be tuned
and altered as the builder sees fit.
Old how-to books make it look easy to
slap a CA motor together. Ha! Fitting and
soldering brass takes practice and skill,
especially if your project is going to safely
handle a powerful supply of compressed air.
This is one reason why the old motors are still
in active use. Whether you try a new or old
CA power plant, wear your safety glasses!
I read yet another Internet discussion about
buddy-box systems that shoot down models.
It’s tough to get the word out to every pilot,
so I’ll write a reminder.
There have been conflicting reports about
which brands and models of radios are
involved, but it is possible to rig two
transmitters with a buddy cord for training or
First Person View (FPV) flying and
inadvertently send radio signals from the
second transmitter. This apparently happens
when a brand of cord other than the radio
brand is used to connect the two boxes.
Because there have been conflicting
reports, I recommend that only a matching
brand of connection cable be used, and it is a
wise precaution to remove the crystals from
the second radio during buddy-box use.
Want to know the future? There is a
wireless buddy-box system being tested,
using some sort of Bluetooth technology.
More than one student can be online, and
there are other keen features. Watch the
appropriate MA columns for details on this
product.
My recent plea for wisdom about electricpower
motor mounts brought in some great email.
Dawson Gillaspy of Long Neck,
Delaware, flies with the Lewes RC Club, but
he has been building models since long before
there was radio control or electric power.
He sent a photo of an unusual method of
mounting a motor to the firewall. He uses
sturdy plastic spacers and says that he has not
had problems with side-load failures.
Dawson wrote:
“The spacers stay perpendicular to the
firewall by the precision molded flat ends,
and the long 6/32-inch screws are held by blind
nuts. If the battery is located near or against
the firewall, it is important that the screw ends
do not protrude beyond the flange of the blind
nuts and allow the battery to impale itself on
the screw ends in a hard landing.
“I’ve used this system in 5-6 different
planes, large and small, and have never
experienced any distortion so I’m
comfortable with that method.”
I was concerned about how this setup
looked. It appears not to be rigid and looks
vulnerable to flexing sideways under the Gforces
of flight maneuvers.
Dawson assured me that the spacers and
screws are oversized and overengineered
for strength, and that is what allows this
system to deal with the stress of flight.
When a guy with that much experience
talks, I listen.
Concerning getting good advice, I
appreciate and enjoy answering the e-mail
and letters I receive. If you have a brilliant
idea or a close-call story, please share it.
Anonymity is available for those such as
me, who are embarrassed by their
occasional lapses of judgment. I should be
used to it by now.
Please put “MA” in your e-mail title so
my spam filter separates you from the fake-
Rolex watch ads. MA
Sources:
Dave Gee
Box 7081
Van Nuys CA 91409
Zurich Sunglasses
(916) 691-6467
www.zurichsunglasses.com
Edition: Model Aviation - 2010/03
Page Numbers: 76,78,80
thrust caused the plane to rotate in my fingers
sufficient to allow the propeller to lacerate my
lower arm.
“Lots of blood everywhere. Luckily, my
wife was with me and drove me to a nearby
emergency room where I received a dozen
stitches. Interestingly, I suffered no pain
during the incident, and had no idea that I’d
been cut so deeply.”
Tom had several lucky breaks on this one,
not the least of which was to have someone
with him at the field. My wife, sweet Diedra,
would have cauterized the wound for me on
the spot with a few choice comments.
Tom’s calm spouse helped him
greatly, but I’ll bet she thinks twice
about going flying with him next
time.
This incident is a classic, because
it reminds us of several important
safety points. As with Tom and me,
many pilots require adult supervision,
so “bring a friend” is a good rule.
You might end up as the helper or the
helpee, but don’t fly alone.
Electric systems can come to life
instantly, and at the most
inconvenient moment. This is tough
for old gas-power fliers to remember.
Those engines do not start
themselves, so the propeller arc is not
a hazard until the engine is roaring.
Not anymore!
A motor can respond to throttlestick
movement anytime the
system is “live.” Many modelers
use arming keys or switches to
avoid accidents such as Tom’s.
There are pros and cons to having
a cutoff feature, but the photo of
Dave Gee | Safety Comes First [email protected]
Propeller-strike injury cuts into a reader’s flying time
A propeller arc is dangerous, even if the motor is off. Tom Chytil
bumped this model’s transmitter and away it went.
Dawson Gillaspy uses plastic spacers and long screws as motor
mounts. They’re sturdy and work fine for him.
This airplane is flying with an antique compressed-air power system. Bud Matthews was
optimistic enough to add a DT.
Also included in this column:
• Eye protection: in your face
again
• Compressed-air power: the
latest in 1880s technology
• Buddy boxes connected to
trouble
• Innovative motor mounts
I LIKE TO start each column with a
“grabber,” and Tom Chytil sent in a
humdinger. His electric-powered RC foam
model has had an eventful history.
It was originally a high-winged version
that was treed twice and badly damaged
during recovery. Tom rebuilt the aircraft as a
midwinger, and the airplane repaid him by
slicing his arm open like a warm bagel.
Tom takes some of the blame, noting that
the model has no will of its own, but I’m not
so sure. He wrote:
“I was at the flying field holding the plane
as shown, walking it a few steps to the takeoff
area. Everything was live. The transmitter
brushed against my leg and knocked the
throttle up to about 30% power. The propeller
76 MODEL AVIATION
03sig3.QXD_00MSTRPG.QXD 1/25/10 1:24 PM Page 76
his arm is a good argument in its favor.
Another point fits in with an e-mail
exchange I had with Scott O’Connor. He is an
experienced RC pilot and a wise man, and he
asked me to stress the concept of propeller-arc
exposure. It seems obvious enough to beware
of inserting body parts into its direct path, but
people do it all the time.
Brightly colored propeller tips and other
aids might help, but a distracted moment and
inadvertent movement are too easy to
experience. Scott went beyond this thought
and asked me to mention keeping awareness
of the arc beyond the actual airscrew.
Most pilots have seen a broken propeller
or rotor sometime. The danger zone for
broken pieces is in the extended disc of the
propeller, so it makes sense to stay out of that
area whenever possible.
When a propeller blade separates or
breaks, the pieces will fly out in a straight line
along the projected propeller arc. Minimize
your exposure in this projected extension of
the propeller by placing your body ahead of or
behind it while servicing your airplane.
Helicopter pilots have a tougher time
with this, since half of their rotors are
horizontal, but they can still arrange for the
minimal exposure possible.
Scott also mentioned the importance of
using proper eye protection. I’m with him
all the way on that point! Getting an arm
stitched up is bad enough, but losing sight
is much more serious to a model-aircraft
pilot.
I often plug Zurich sunglasses, because
their impact-resistant wraparounds are my
favorite. No matter how vigilant we are at
the field, some piece of fast-moving debris
might find us. Please get in the habit of
wearing appropriate eye protection!
Zurich International is a frequent
advertiser in this magazine, but there are other
excellent products available. I urge you to
consider making safety-rated glasses a part of
your outfit at the field as well as in your shop.
How about something really old school that
requires eye protection? Before electric
power, before even gas power, there was
compressed air (CA). This quiet and
challenging power system is experiencing a
small resurgence among the Old-Timer
crowd.
CA models have to be extremely well
designed to fly. Extra weight is a killer, since
the setup requires a large propeller, fairly
heavy motor, and a giant onboard pressure
vessel to hold the “fuel.”
CA pilots are mindful of what can happen
when an ultralightweight tank is filled with
enough pressure to operate an aircraft motor.
Take a look at Tony Naccarato’s photo of Bud
Matthew’s airplane chugging overhead.
The model uses a borrowed motor and
tank, both of which are antiques. Bud had to
repair several leaks in the tank using oldfashioned
solder on the paper-thin brass tank
body.
Some airplanes carry their pressurized
power in modern soda bottles. This lacks the
historical appearance and romance of the old
tanks, but avoids sending near-priceless
artifacts into the sky on an FF model. Those
pop bottles can really “pop” sometimes, so
eye protection is a must when using any CA
rig.
I think that the new Air Hogs flying toys
are partly to blame for the resurgence of CA
flight. These inexpensive airplanes and
helicopters are ready to fly, and boy do they
fly! Their motors are small for transplanting
into serious models, but some designers make
good use of them.
My friend, Ken Johnson, has flown and
had published some neat models that use
commercial motors. There is not much
tinkering or souping up possible on these
molded-plastic expansion motors, unlike the
classic handmade systems that can be tuned
and altered as the builder sees fit.
Old how-to books make it look easy to
slap a CA motor together. Ha! Fitting and
soldering brass takes practice and skill,
especially if your project is going to safely
handle a powerful supply of compressed air.
This is one reason why the old motors are still
in active use. Whether you try a new or old
CA power plant, wear your safety glasses!
I read yet another Internet discussion about
buddy-box systems that shoot down models.
It’s tough to get the word out to every pilot,
so I’ll write a reminder.
There have been conflicting reports about
which brands and models of radios are
involved, but it is possible to rig two
transmitters with a buddy cord for training or
First Person View (FPV) flying and
inadvertently send radio signals from the
second transmitter. This apparently happens
when a brand of cord other than the radio
brand is used to connect the two boxes.
Because there have been conflicting
reports, I recommend that only a matching
brand of connection cable be used, and it is a
wise precaution to remove the crystals from
the second radio during buddy-box use.
Want to know the future? There is a
wireless buddy-box system being tested,
using some sort of Bluetooth technology.
More than one student can be online, and
there are other keen features. Watch the
appropriate MA columns for details on this
product.
My recent plea for wisdom about electricpower
motor mounts brought in some great email.
Dawson Gillaspy of Long Neck,
Delaware, flies with the Lewes RC Club, but
he has been building models since long before
there was radio control or electric power.
He sent a photo of an unusual method of
mounting a motor to the firewall. He uses
sturdy plastic spacers and says that he has not
had problems with side-load failures.
Dawson wrote:
“The spacers stay perpendicular to the
firewall by the precision molded flat ends,
and the long 6/32-inch screws are held by blind
nuts. If the battery is located near or against
the firewall, it is important that the screw ends
do not protrude beyond the flange of the blind
nuts and allow the battery to impale itself on
the screw ends in a hard landing.
“I’ve used this system in 5-6 different
planes, large and small, and have never
experienced any distortion so I’m
comfortable with that method.”
I was concerned about how this setup
looked. It appears not to be rigid and looks
vulnerable to flexing sideways under the Gforces
of flight maneuvers.
Dawson assured me that the spacers and
screws are oversized and overengineered
for strength, and that is what allows this
system to deal with the stress of flight.
When a guy with that much experience
talks, I listen.
Concerning getting good advice, I
appreciate and enjoy answering the e-mail
and letters I receive. If you have a brilliant
idea or a close-call story, please share it.
Anonymity is available for those such as
me, who are embarrassed by their
occasional lapses of judgment. I should be
used to it by now.
Please put “MA” in your e-mail title so
my spam filter separates you from the fake-
Rolex watch ads. MA
Sources:
Dave Gee
Box 7081
Van Nuys CA 91409
Zurich Sunglasses
(916) 691-6467
www.zurichsunglasses.com
