BILL HINNANT, noted modeler, was
heard to say, “Everytime I see a model
crash, it is like losing a friend.” There is a
simple method, if properly applied, that
will save many aircraft and prevent many
crashes.
The “device,” as I’ll call it, is to add a
small weight to the right wingtip. The
amount depends on the airplane, but the
device will work on any size of model,
from a 1/4-scale Hawker Hurricane to a
small rubber-powered aircraft.
Following are some illustrative cases.
• Bill McMullen, an experienced pilot,
was flying Mike Dale’s 84-inch Hurricane
for the first time. It was heavy and
powered by a YS 1.40 four-stroke monster
engine.
Bill recovered the Hurricane from a
typical left yaw on its first takeoff, but the
first landing pass with the new hot model
didn’t go so well. After almost touching
down with the aircraft, he applied full
throttle. The airplane responded by doing a
October 2009 37
Above: Mike Dale totes his 84-inch Hurricane that Bill McMullen flew for
the first time. The model had a nasty tendency to yaw hard to the left
before the installation of the antitorque device. Tom Schmitt photo.
Above right: After applying a 3-ounce, stick-on weight to the right
wingtip, all torque effects disappeared and the Hurricane, although still
fast, became docile and easy to take off, fly, and land. Schmitt photo.
The author’s electric-powered Northrop Gamma used to slow roll to
the left under full power. A nickel under the right wingtip corrected
it. Subsequent flights were normal, even with the odd ailerons. Pat
Daily photo.
This scaled-up, Rees-designed Lockheed Vega has little
dihedral and no ailerons; with only rudder for directional
control, it would turn well to the left but not to the right,
until a quarter was added to the right wingtip. Now the
Vega turns well in both directions. John Hunton photo.
Keep the wings
level at all costs
Photos as noted
10sig2.QXD 8/21/09 1:58 PM Page 37
partial snap roll to the left. Only through
Bill’s experience and quick action could
he recover it.
After applying a stick-on 3-ounce
weight to the model’s right wingtip, all
torque effects disappeared. Although the
Hurricane is still fast, it has become docile
and easy to take off, fly, and land.
• My electric-powered RC Northrop
Gamma had the distinctive “park bench”
ailerons. When I hand-launched it under
full power on its first flight, the model
began a slow roll to the left that increased
even when I applied full right aileron.
When I cut power for the seemingly
inevitable ground contact, the aircraft
rolled right and landed properly.
After installing a nickel in the
Gamma’s right wingtip, subsequent flights
were normal—even with the odd ailerons.
• Cox made a neat-looking purple-andyellow
electric FF Mustang RTF. If it was
trimmed to survive the powered part of the
flight, it would spin in to the right when
the battery ran down. If it was trimmed to
glide properly, it would spin in to the left
under power.
With a penny under the right wingtip,
this little model would fly straight under
power and under glide. If turn trim was put
into it, the Mustang would fly in a nearly
uniform circle for its whole flight.
The Theory: Visualize an airplane in
cruising flight. The engine is creating
thrust, and there is the accompanying left
torque force. We compensate for torque in
an RC model by trimming in a bit of right
aileron or right rudder.
If we placed a weight in the right
wingtip sufficient to counter this torque
effect, the controls could be trimmed
neutral. The wingtip’s moment arm is
large; therefore, the weight can be rather
small. This is the antitorque device’s
primary effect.
A secondary effect is that when the
aircraft is accelerating for takeoff, the tip
weight’s inertial force creates a rearward
yawing force that directly counteracts the
torque’s tendency to make the airplane roll
to the left. That is probably the device’s
most important “model-saving” effect: its
propensity to counteract torque at takeoff
or when a go-around condition comes up
and power must be applied.
This device’s use on any RC trainer
would greatly simplify what the novice
has to contend with when first learning to
fly.
How much of the device do I need? The
approximate amount of weight to be
Notice to RC Airmen
Let’s say you have been building your ultimate Scale
model for several months, and it is time to fly this heavy but
great-looking aircraft. It’s summertime, the density altitude is
extremely high, and the engine isn’t producing its typical
power. The runway is slightly short, but you are assured that
the airplane should make it okay.
The model trundles down the runway. The tail finally
comes up, but the end of the runway is getting close. You put
in some up, but the aircraft is still taxiing. It is running out of
runway, so you horse it into the air.
You have been building a lot, and your flying skills are not
up to par. The airplane begins to roll slowly to the left,
because of torque effect. You correct for the roll by adding
right aileron.
Now the left wing has a higher effective angle of attack
than the right wing, because the left aileron is deflected
downward. The left wing stalls, and the beautiful model rolls
sharply to the left and clobbers itself.
The previous scenario happens frequently. Employing the
antitorque device can ensure that this scenario is unlikely to
happen again. MA
—John Hunton
10sig2.QXD 8/21/09 1:30 PM Page 38
installed to counteract torque forces on
any model can be approximated by using
the following formula.
W (ounces) = Engine Displacement
(cu. in.) x 2
A typical .049-powered sport model
will need 0.10 ounce of tip weight, a .40-
powered model will need 0.8 ounce, and a
.60 model will need 1.2 ounces. These
weight amounts should be applied in a
temporary fashion, and then the model
needs to be tested to see if any more or
less weight is needed.
The amount of weight will vary with
wingspans and engine power, but this
formula will get you going enough to test
the theory and save a model.
Try my antitorque device for sport and
Scale flying. I think you will like it. MA
John Hunton
[email protected]
Edition: Model Aviation - 2009/10
Page Numbers: 36,37,38,40
Edition: Model Aviation - 2009/10
Page Numbers: 36,37,38,40
BILL HINNANT, noted modeler, was
heard to say, “Everytime I see a model
crash, it is like losing a friend.” There is a
simple method, if properly applied, that
will save many aircraft and prevent many
crashes.
The “device,” as I’ll call it, is to add a
small weight to the right wingtip. The
amount depends on the airplane, but the
device will work on any size of model,
from a 1/4-scale Hawker Hurricane to a
small rubber-powered aircraft.
Following are some illustrative cases.
• Bill McMullen, an experienced pilot,
was flying Mike Dale’s 84-inch Hurricane
for the first time. It was heavy and
powered by a YS 1.40 four-stroke monster
engine.
Bill recovered the Hurricane from a
typical left yaw on its first takeoff, but the
first landing pass with the new hot model
didn’t go so well. After almost touching
down with the aircraft, he applied full
throttle. The airplane responded by doing a
October 2009 37
Above: Mike Dale totes his 84-inch Hurricane that Bill McMullen flew for
the first time. The model had a nasty tendency to yaw hard to the left
before the installation of the antitorque device. Tom Schmitt photo.
Above right: After applying a 3-ounce, stick-on weight to the right
wingtip, all torque effects disappeared and the Hurricane, although still
fast, became docile and easy to take off, fly, and land. Schmitt photo.
The author’s electric-powered Northrop Gamma used to slow roll to
the left under full power. A nickel under the right wingtip corrected
it. Subsequent flights were normal, even with the odd ailerons. Pat
Daily photo.
This scaled-up, Rees-designed Lockheed Vega has little
dihedral and no ailerons; with only rudder for directional
control, it would turn well to the left but not to the right,
until a quarter was added to the right wingtip. Now the
Vega turns well in both directions. John Hunton photo.
Keep the wings
level at all costs
Photos as noted
10sig2.QXD 8/21/09 1:58 PM Page 37
partial snap roll to the left. Only through
Bill’s experience and quick action could
he recover it.
After applying a stick-on 3-ounce
weight to the model’s right wingtip, all
torque effects disappeared. Although the
Hurricane is still fast, it has become docile
and easy to take off, fly, and land.
• My electric-powered RC Northrop
Gamma had the distinctive “park bench”
ailerons. When I hand-launched it under
full power on its first flight, the model
began a slow roll to the left that increased
even when I applied full right aileron.
When I cut power for the seemingly
inevitable ground contact, the aircraft
rolled right and landed properly.
After installing a nickel in the
Gamma’s right wingtip, subsequent flights
were normal—even with the odd ailerons.
• Cox made a neat-looking purple-andyellow
electric FF Mustang RTF. If it was
trimmed to survive the powered part of the
flight, it would spin in to the right when
the battery ran down. If it was trimmed to
glide properly, it would spin in to the left
under power.
With a penny under the right wingtip,
this little model would fly straight under
power and under glide. If turn trim was put
into it, the Mustang would fly in a nearly
uniform circle for its whole flight.
The Theory: Visualize an airplane in
cruising flight. The engine is creating
thrust, and there is the accompanying left
torque force. We compensate for torque in
an RC model by trimming in a bit of right
aileron or right rudder.
If we placed a weight in the right
wingtip sufficient to counter this torque
effect, the controls could be trimmed
neutral. The wingtip’s moment arm is
large; therefore, the weight can be rather
small. This is the antitorque device’s
primary effect.
A secondary effect is that when the
aircraft is accelerating for takeoff, the tip
weight’s inertial force creates a rearward
yawing force that directly counteracts the
torque’s tendency to make the airplane roll
to the left. That is probably the device’s
most important “model-saving” effect: its
propensity to counteract torque at takeoff
or when a go-around condition comes up
and power must be applied.
This device’s use on any RC trainer
would greatly simplify what the novice
has to contend with when first learning to
fly.
How much of the device do I need? The
approximate amount of weight to be
Notice to RC Airmen
Let’s say you have been building your ultimate Scale
model for several months, and it is time to fly this heavy but
great-looking aircraft. It’s summertime, the density altitude is
extremely high, and the engine isn’t producing its typical
power. The runway is slightly short, but you are assured that
the airplane should make it okay.
The model trundles down the runway. The tail finally
comes up, but the end of the runway is getting close. You put
in some up, but the aircraft is still taxiing. It is running out of
runway, so you horse it into the air.
You have been building a lot, and your flying skills are not
up to par. The airplane begins to roll slowly to the left,
because of torque effect. You correct for the roll by adding
right aileron.
Now the left wing has a higher effective angle of attack
than the right wing, because the left aileron is deflected
downward. The left wing stalls, and the beautiful model rolls
sharply to the left and clobbers itself.
The previous scenario happens frequently. Employing the
antitorque device can ensure that this scenario is unlikely to
happen again. MA
—John Hunton
10sig2.QXD 8/21/09 1:30 PM Page 38
installed to counteract torque forces on
any model can be approximated by using
the following formula.
W (ounces) = Engine Displacement
(cu. in.) x 2
A typical .049-powered sport model
will need 0.10 ounce of tip weight, a .40-
powered model will need 0.8 ounce, and a
.60 model will need 1.2 ounces. These
weight amounts should be applied in a
temporary fashion, and then the model
needs to be tested to see if any more or
less weight is needed.
The amount of weight will vary with
wingspans and engine power, but this
formula will get you going enough to test
the theory and save a model.
Try my antitorque device for sport and
Scale flying. I think you will like it. MA
John Hunton
[email protected]
Edition: Model Aviation - 2009/10
Page Numbers: 36,37,38,40
BILL HINNANT, noted modeler, was
heard to say, “Everytime I see a model
crash, it is like losing a friend.” There is a
simple method, if properly applied, that
will save many aircraft and prevent many
crashes.
The “device,” as I’ll call it, is to add a
small weight to the right wingtip. The
amount depends on the airplane, but the
device will work on any size of model,
from a 1/4-scale Hawker Hurricane to a
small rubber-powered aircraft.
Following are some illustrative cases.
• Bill McMullen, an experienced pilot,
was flying Mike Dale’s 84-inch Hurricane
for the first time. It was heavy and
powered by a YS 1.40 four-stroke monster
engine.
Bill recovered the Hurricane from a
typical left yaw on its first takeoff, but the
first landing pass with the new hot model
didn’t go so well. After almost touching
down with the aircraft, he applied full
throttle. The airplane responded by doing a
October 2009 37
Above: Mike Dale totes his 84-inch Hurricane that Bill McMullen flew for
the first time. The model had a nasty tendency to yaw hard to the left
before the installation of the antitorque device. Tom Schmitt photo.
Above right: After applying a 3-ounce, stick-on weight to the right
wingtip, all torque effects disappeared and the Hurricane, although still
fast, became docile and easy to take off, fly, and land. Schmitt photo.
The author’s electric-powered Northrop Gamma used to slow roll to
the left under full power. A nickel under the right wingtip corrected
it. Subsequent flights were normal, even with the odd ailerons. Pat
Daily photo.
This scaled-up, Rees-designed Lockheed Vega has little
dihedral and no ailerons; with only rudder for directional
control, it would turn well to the left but not to the right,
until a quarter was added to the right wingtip. Now the
Vega turns well in both directions. John Hunton photo.
Keep the wings
level at all costs
Photos as noted
10sig2.QXD 8/21/09 1:58 PM Page 37
partial snap roll to the left. Only through
Bill’s experience and quick action could
he recover it.
After applying a stick-on 3-ounce
weight to the model’s right wingtip, all
torque effects disappeared. Although the
Hurricane is still fast, it has become docile
and easy to take off, fly, and land.
• My electric-powered RC Northrop
Gamma had the distinctive “park bench”
ailerons. When I hand-launched it under
full power on its first flight, the model
began a slow roll to the left that increased
even when I applied full right aileron.
When I cut power for the seemingly
inevitable ground contact, the aircraft
rolled right and landed properly.
After installing a nickel in the
Gamma’s right wingtip, subsequent flights
were normal—even with the odd ailerons.
• Cox made a neat-looking purple-andyellow
electric FF Mustang RTF. If it was
trimmed to survive the powered part of the
flight, it would spin in to the right when
the battery ran down. If it was trimmed to
glide properly, it would spin in to the left
under power.
With a penny under the right wingtip,
this little model would fly straight under
power and under glide. If turn trim was put
into it, the Mustang would fly in a nearly
uniform circle for its whole flight.
The Theory: Visualize an airplane in
cruising flight. The engine is creating
thrust, and there is the accompanying left
torque force. We compensate for torque in
an RC model by trimming in a bit of right
aileron or right rudder.
If we placed a weight in the right
wingtip sufficient to counter this torque
effect, the controls could be trimmed
neutral. The wingtip’s moment arm is
large; therefore, the weight can be rather
small. This is the antitorque device’s
primary effect.
A secondary effect is that when the
aircraft is accelerating for takeoff, the tip
weight’s inertial force creates a rearward
yawing force that directly counteracts the
torque’s tendency to make the airplane roll
to the left. That is probably the device’s
most important “model-saving” effect: its
propensity to counteract torque at takeoff
or when a go-around condition comes up
and power must be applied.
This device’s use on any RC trainer
would greatly simplify what the novice
has to contend with when first learning to
fly.
How much of the device do I need? The
approximate amount of weight to be
Notice to RC Airmen
Let’s say you have been building your ultimate Scale
model for several months, and it is time to fly this heavy but
great-looking aircraft. It’s summertime, the density altitude is
extremely high, and the engine isn’t producing its typical
power. The runway is slightly short, but you are assured that
the airplane should make it okay.
The model trundles down the runway. The tail finally
comes up, but the end of the runway is getting close. You put
in some up, but the aircraft is still taxiing. It is running out of
runway, so you horse it into the air.
You have been building a lot, and your flying skills are not
up to par. The airplane begins to roll slowly to the left,
because of torque effect. You correct for the roll by adding
right aileron.
Now the left wing has a higher effective angle of attack
than the right wing, because the left aileron is deflected
downward. The left wing stalls, and the beautiful model rolls
sharply to the left and clobbers itself.
The previous scenario happens frequently. Employing the
antitorque device can ensure that this scenario is unlikely to
happen again. MA
—John Hunton
10sig2.QXD 8/21/09 1:30 PM Page 38
installed to counteract torque forces on
any model can be approximated by using
the following formula.
W (ounces) = Engine Displacement
(cu. in.) x 2
A typical .049-powered sport model
will need 0.10 ounce of tip weight, a .40-
powered model will need 0.8 ounce, and a
.60 model will need 1.2 ounces. These
weight amounts should be applied in a
temporary fashion, and then the model
needs to be tested to see if any more or
less weight is needed.
The amount of weight will vary with
wingspans and engine power, but this
formula will get you going enough to test
the theory and save a model.
Try my antitorque device for sport and
Scale flying. I think you will like it. MA
John Hunton
[email protected]
Edition: Model Aviation - 2009/10
Page Numbers: 36,37,38,40
BILL HINNANT, noted modeler, was
heard to say, “Everytime I see a model
crash, it is like losing a friend.” There is a
simple method, if properly applied, that
will save many aircraft and prevent many
crashes.
The “device,” as I’ll call it, is to add a
small weight to the right wingtip. The
amount depends on the airplane, but the
device will work on any size of model,
from a 1/4-scale Hawker Hurricane to a
small rubber-powered aircraft.
Following are some illustrative cases.
• Bill McMullen, an experienced pilot,
was flying Mike Dale’s 84-inch Hurricane
for the first time. It was heavy and
powered by a YS 1.40 four-stroke monster
engine.
Bill recovered the Hurricane from a
typical left yaw on its first takeoff, but the
first landing pass with the new hot model
didn’t go so well. After almost touching
down with the aircraft, he applied full
throttle. The airplane responded by doing a
October 2009 37
Above: Mike Dale totes his 84-inch Hurricane that Bill McMullen flew for
the first time. The model had a nasty tendency to yaw hard to the left
before the installation of the antitorque device. Tom Schmitt photo.
Above right: After applying a 3-ounce, stick-on weight to the right
wingtip, all torque effects disappeared and the Hurricane, although still
fast, became docile and easy to take off, fly, and land. Schmitt photo.
The author’s electric-powered Northrop Gamma used to slow roll to
the left under full power. A nickel under the right wingtip corrected
it. Subsequent flights were normal, even with the odd ailerons. Pat
Daily photo.
This scaled-up, Rees-designed Lockheed Vega has little
dihedral and no ailerons; with only rudder for directional
control, it would turn well to the left but not to the right,
until a quarter was added to the right wingtip. Now the
Vega turns well in both directions. John Hunton photo.
Keep the wings
level at all costs
Photos as noted
10sig2.QXD 8/21/09 1:58 PM Page 37
partial snap roll to the left. Only through
Bill’s experience and quick action could
he recover it.
After applying a stick-on 3-ounce
weight to the model’s right wingtip, all
torque effects disappeared. Although the
Hurricane is still fast, it has become docile
and easy to take off, fly, and land.
• My electric-powered RC Northrop
Gamma had the distinctive “park bench”
ailerons. When I hand-launched it under
full power on its first flight, the model
began a slow roll to the left that increased
even when I applied full right aileron.
When I cut power for the seemingly
inevitable ground contact, the aircraft
rolled right and landed properly.
After installing a nickel in the
Gamma’s right wingtip, subsequent flights
were normal—even with the odd ailerons.
• Cox made a neat-looking purple-andyellow
electric FF Mustang RTF. If it was
trimmed to survive the powered part of the
flight, it would spin in to the right when
the battery ran down. If it was trimmed to
glide properly, it would spin in to the left
under power.
With a penny under the right wingtip,
this little model would fly straight under
power and under glide. If turn trim was put
into it, the Mustang would fly in a nearly
uniform circle for its whole flight.
The Theory: Visualize an airplane in
cruising flight. The engine is creating
thrust, and there is the accompanying left
torque force. We compensate for torque in
an RC model by trimming in a bit of right
aileron or right rudder.
If we placed a weight in the right
wingtip sufficient to counter this torque
effect, the controls could be trimmed
neutral. The wingtip’s moment arm is
large; therefore, the weight can be rather
small. This is the antitorque device’s
primary effect.
A secondary effect is that when the
aircraft is accelerating for takeoff, the tip
weight’s inertial force creates a rearward
yawing force that directly counteracts the
torque’s tendency to make the airplane roll
to the left. That is probably the device’s
most important “model-saving” effect: its
propensity to counteract torque at takeoff
or when a go-around condition comes up
and power must be applied.
This device’s use on any RC trainer
would greatly simplify what the novice
has to contend with when first learning to
fly.
How much of the device do I need? The
approximate amount of weight to be
Notice to RC Airmen
Let’s say you have been building your ultimate Scale
model for several months, and it is time to fly this heavy but
great-looking aircraft. It’s summertime, the density altitude is
extremely high, and the engine isn’t producing its typical
power. The runway is slightly short, but you are assured that
the airplane should make it okay.
The model trundles down the runway. The tail finally
comes up, but the end of the runway is getting close. You put
in some up, but the aircraft is still taxiing. It is running out of
runway, so you horse it into the air.
You have been building a lot, and your flying skills are not
up to par. The airplane begins to roll slowly to the left,
because of torque effect. You correct for the roll by adding
right aileron.
Now the left wing has a higher effective angle of attack
than the right wing, because the left aileron is deflected
downward. The left wing stalls, and the beautiful model rolls
sharply to the left and clobbers itself.
The previous scenario happens frequently. Employing the
antitorque device can ensure that this scenario is unlikely to
happen again. MA
—John Hunton
10sig2.QXD 8/21/09 1:30 PM Page 38
installed to counteract torque forces on
any model can be approximated by using
the following formula.
W (ounces) = Engine Displacement
(cu. in.) x 2
A typical .049-powered sport model
will need 0.10 ounce of tip weight, a .40-
powered model will need 0.8 ounce, and a
.60 model will need 1.2 ounces. These
weight amounts should be applied in a
temporary fashion, and then the model
needs to be tested to see if any more or
less weight is needed.
The amount of weight will vary with
wingspans and engine power, but this
formula will get you going enough to test
the theory and save a model.
Try my antitorque device for sport and
Scale flying. I think you will like it. MA
John Hunton
[email protected]