Also included in this column:
• Composite-ARF’s Lightning
sport jet
• Understanding static-electricity
issues
REPAIR TECHNOLOGY International
(RTI) has introduced the RTI 2800 Special
Edition turbine of its own manufacture.
Carlos Villarreal, the man behind RTI, has
been supporting parts and repair services
for the RAM turbines since that company’s
demise. After years of valuable experience
repairing RAM and JetCat turbines, Carlos
has decided to step into the market with
the RTI 2800.
The RTI 2800 is a 66mm turbine of
conventional layout. It will feature an
inconel combustion chamber, which is
necessary for its long life. The turbine
wheel is of Swiss manufacture and is of
the highest proven quality.
Carlos is applying his years of
experience to fine-tune this engine to
produce a reliable, guaranteed 28 pounds
of thrust. Many manufacturers claim 28
pounds of thrust, but their turbines don’t
produce that figure in the real world. Many
factors affect thrust including temperature,
humidity, and altitude, in addition to
normal production variations. For RTI to
guarantee its thrust rating is a bold step.
From years of testing thrust, I know
this is difficult to do in production. It’s
harder still to deal with the understanding
of the effect altitude density has on
performance, hence our expectations of a
28-pound-thrust turbine at sea level on a
standard day versus a hot, humid Midwest
summer day.
I like this guarantee and hope it
pressures all manufacturers to be realistic
in their claims of thrust ratings as opposed
to the real thrust delivered by turbines.
The RTI 2800 Special Edition will
come with electronics supplied by RJP
Models—a company with many years of
experience producing engine control units
(ECUs) for model turbines. The software
will be open for the modeler to fine-tune
parameters to suit his or her preferences.
Included in the software will be a throttlecurve
adjustment for altitude compensation
when required. Factory settings will
provide a 3.5- to 4.0-second acceleration
time from idle to full throttle—a realistic
figure for a quality turbine in this class.
Chuck Shull’s large, aerobatic Composite-ARF Lightning, designed for a 34-pound-thrust
turbine, with its attractive lines and striking colors.
The Lightning’s flap extends above the
wing when deflected to increase drag and
improve landing-approach accuracy.
Included with the purchase of the RTI
2800 Special Edition is the turbine
engine, a fuel pump, ECU, required
solenoids, and an 1800 mAh six-cell Ni-
Cd battery pack. The cost of this package
is currently set at $3,250. The RTI 2800
can be set up to run on Li-Poly batteries
or NiMH batteries if that is your
preference.
RTI is a full product distributor for
necessary support equipment for your
turbine operations in addition to the repair
service. You can find full information on
its products and services including the
new RTI 2800 Special Edition turbine at
www.rtiturbines.com.
Composite-ARF introduced the
Lightning sport jet early in 2006, and it
has proven to be a popular model. The
Lightning is large and has a conventional
layout with an emphasis on ease of flying
and assembly. Don’t be mislead, though;
this is a serious precision aerobatic model
designed to perform complicated routines.
Construction of the Lightning follows
Composite-ARF’s now-traditional use of
composite structures with balsa and
hardwood for internals and Kevlar and
carbon-fiber reinforcements. This
provides a light, rigid model that is able
to handle the extreme loads of high-speed
flight.
The Lightning follows the hugely
popular Eurosport. It spans 79 inches and
is 102 inches in length. It is a large model
intended to be powered by 160N turbines
or those with 34-pound thrust or greater.
You can expect an empty weight of
roughly 30 pounds, so you will have a
reasonably light wing loading. With great
power-to-weight ratio, this makes for
incredible performance.
Typical of Composite-ARF models, the
Lightning is available in a variety of color
schemes ranging from sport aerobatic to
military. The Jolly Roger scheme makes
for a smart-looking aircraft, while the
Navy version adds some high-visibility
colors to the traditional gray camouflage.
You can’t go wrong with any of them.
This big model with its attractive lines
presents itself well.
Breakdown for transportation of the
Lightning is handled with features such as
the two-piece wing, removable stabilizer,
and removable fin. The nose cone is also
removable.
Access to the interior of the airplane is
through a large canopy hatch on the top
and an extremely large removable bottom
hatch. This lower hatch extends from the
LE of the wing to the LE of the stabilizer,
giving plenty of access to load the turbine
and all those systems we carry.
The Lightning features a unique flap
design that is hinged on the bottom but
extends forward on the top. When
deflected, this arrangement allows the flap
to extend above the upper wing surface to
act as a drag device on top—similar to a
spoiler—while deflecting the air
downward off the bottom surface, similar
to a traditional flap.
This is a neat idea and appears to work
effectively. The flap servo mount is well
thought out and clear of the wheel well;
this makes for a nice installation.
Construction and finish of the
Lightning includes features such as
factory-installed internal ductwork. The
fuselage has traditional formers to stiffen
the airframe and provide hard mounting
points for critical equipment. All control
surfaces are factory hinged—another
convenience for the builder.
As I mentioned earlier, the fin is bolted
on with a carbon-fiber tube support. The
one-piece stabilizer bolts onto the
fuselage. Included with the model is a
complete set of gear doors that neatly
hides the landing gear and tires when
retracted.
The wing carry-through is a traditional
aluminum tube that extends all the way
out the main landing-gear retract units to
ensure a solid structure to transfer those
hard landing loads. The main landing gear
has an extremely wide track to maximize
ground handling and it does this well. A
trailing-link nose gear is available as part
of the retract accessory kit; again, this
helps with straight, positive ground
tracking.
The provided fuel tanks are custommolded
Kevlar fitted around the inlet
ductwork and nearly centered over the
wing carry-through. This tank design
incorporates baffling to reduce fuel
sloshing. The tanks are Y connected to a
header tank for final feed to the fuel
pump. An optional extended-range fuel
tank is available and can be configured to
hold 1.5-2.1 liters of additional fuel or it
could be used to hold smoke oil for an airshow
performance.
For more information about the
Composite-ARF Lightning, check out the
company’s Web site at www.compositearf.
com. The site even includes the
instruction manual so the customer can
learn much about the model before
purchasing.
The cost varies based on color schemes
but ranges from $2,800 to $3,200. The
retract gear set with wheels and brakes
will add another $949.
The Lightning is a lot of aircraft and
comes complete with many systems!
A new subject is making the rounds
throughout the jet-modeling community:
static electricity and turbine shutdowns. A
strong effort is underway to understand,
explain, and prevent turbine shutdowns
caused by static electricity that usually
happen immediately following takeoff.
This problem appears to be related to the
larger turbines now in use.
An initial theory blamed the problem
on static buildup during takeoff from the
fast-rolling tires, but this appears to have
been debunked. The currently accepted
theory is that fuel flowing through the
airplane is the source of unwanted static
buildup.
The larger engines in use today
consume large volumes of kerosene, and
the fuel flows at high velocity through the
fuel lines. Common practice is to use the
same-size fuel lines regardless of the
turbine’s fuel-flow requirements. I have
used giant-scale-size lines from day one
on the fuel lines inside the tanks and all
the way to the fuel pump, whether it is on
a turbine with only 8 pounds of thrust or
one with as much as 40 pounds of thrust.
The theory is that as the fuel flows at
greater speeds through the fuel lines, static
electricity builds up and is released into
the ECU, causing inadvertent turbine
shutdowns usually early in the flight when
the model is fully laden with fuel, and this
is a bad situation.
Another source of fuel movement is the
use of large Kevlar fuel tanks without
baffling, which allows fuel to slosh around
and create a static-charge buildup.
Current discussions and developments
center on how to dissipate static charges
with conductive fuel lines or fuel tanks
with conductive material. Even fuel
additives in the kerosene are being
considered.
JetCat USA is heavy into investigating
this issue and has some good information
on its Web site: www.jetcatusa.com. I am
sure we will be hearing more about this
subject as additional knowledge and
solutions are developed.
It’s time for me to pack and get on to
flying, so have a good day and see you at
the jet meets.
Edition: Model Aviation - 2007/02
Page Numbers: 123,124,126,128
Edition: Model Aviation - 2007/02
Page Numbers: 123,124,126,128
Also included in this column:
• Composite-ARF’s Lightning
sport jet
• Understanding static-electricity
issues
REPAIR TECHNOLOGY International
(RTI) has introduced the RTI 2800 Special
Edition turbine of its own manufacture.
Carlos Villarreal, the man behind RTI, has
been supporting parts and repair services
for the RAM turbines since that company’s
demise. After years of valuable experience
repairing RAM and JetCat turbines, Carlos
has decided to step into the market with
the RTI 2800.
The RTI 2800 is a 66mm turbine of
conventional layout. It will feature an
inconel combustion chamber, which is
necessary for its long life. The turbine
wheel is of Swiss manufacture and is of
the highest proven quality.
Carlos is applying his years of
experience to fine-tune this engine to
produce a reliable, guaranteed 28 pounds
of thrust. Many manufacturers claim 28
pounds of thrust, but their turbines don’t
produce that figure in the real world. Many
factors affect thrust including temperature,
humidity, and altitude, in addition to
normal production variations. For RTI to
guarantee its thrust rating is a bold step.
From years of testing thrust, I know
this is difficult to do in production. It’s
harder still to deal with the understanding
of the effect altitude density has on
performance, hence our expectations of a
28-pound-thrust turbine at sea level on a
standard day versus a hot, humid Midwest
summer day.
I like this guarantee and hope it
pressures all manufacturers to be realistic
in their claims of thrust ratings as opposed
to the real thrust delivered by turbines.
The RTI 2800 Special Edition will
come with electronics supplied by RJP
Models—a company with many years of
experience producing engine control units
(ECUs) for model turbines. The software
will be open for the modeler to fine-tune
parameters to suit his or her preferences.
Included in the software will be a throttlecurve
adjustment for altitude compensation
when required. Factory settings will
provide a 3.5- to 4.0-second acceleration
time from idle to full throttle—a realistic
figure for a quality turbine in this class.
Chuck Shull’s large, aerobatic Composite-ARF Lightning, designed for a 34-pound-thrust
turbine, with its attractive lines and striking colors.
The Lightning’s flap extends above the
wing when deflected to increase drag and
improve landing-approach accuracy.
Included with the purchase of the RTI
2800 Special Edition is the turbine
engine, a fuel pump, ECU, required
solenoids, and an 1800 mAh six-cell Ni-
Cd battery pack. The cost of this package
is currently set at $3,250. The RTI 2800
can be set up to run on Li-Poly batteries
or NiMH batteries if that is your
preference.
RTI is a full product distributor for
necessary support equipment for your
turbine operations in addition to the repair
service. You can find full information on
its products and services including the
new RTI 2800 Special Edition turbine at
www.rtiturbines.com.
Composite-ARF introduced the
Lightning sport jet early in 2006, and it
has proven to be a popular model. The
Lightning is large and has a conventional
layout with an emphasis on ease of flying
and assembly. Don’t be mislead, though;
this is a serious precision aerobatic model
designed to perform complicated routines.
Construction of the Lightning follows
Composite-ARF’s now-traditional use of
composite structures with balsa and
hardwood for internals and Kevlar and
carbon-fiber reinforcements. This
provides a light, rigid model that is able
to handle the extreme loads of high-speed
flight.
The Lightning follows the hugely
popular Eurosport. It spans 79 inches and
is 102 inches in length. It is a large model
intended to be powered by 160N turbines
or those with 34-pound thrust or greater.
You can expect an empty weight of
roughly 30 pounds, so you will have a
reasonably light wing loading. With great
power-to-weight ratio, this makes for
incredible performance.
Typical of Composite-ARF models, the
Lightning is available in a variety of color
schemes ranging from sport aerobatic to
military. The Jolly Roger scheme makes
for a smart-looking aircraft, while the
Navy version adds some high-visibility
colors to the traditional gray camouflage.
You can’t go wrong with any of them.
This big model with its attractive lines
presents itself well.
Breakdown for transportation of the
Lightning is handled with features such as
the two-piece wing, removable stabilizer,
and removable fin. The nose cone is also
removable.
Access to the interior of the airplane is
through a large canopy hatch on the top
and an extremely large removable bottom
hatch. This lower hatch extends from the
LE of the wing to the LE of the stabilizer,
giving plenty of access to load the turbine
and all those systems we carry.
The Lightning features a unique flap
design that is hinged on the bottom but
extends forward on the top. When
deflected, this arrangement allows the flap
to extend above the upper wing surface to
act as a drag device on top—similar to a
spoiler—while deflecting the air
downward off the bottom surface, similar
to a traditional flap.
This is a neat idea and appears to work
effectively. The flap servo mount is well
thought out and clear of the wheel well;
this makes for a nice installation.
Construction and finish of the
Lightning includes features such as
factory-installed internal ductwork. The
fuselage has traditional formers to stiffen
the airframe and provide hard mounting
points for critical equipment. All control
surfaces are factory hinged—another
convenience for the builder.
As I mentioned earlier, the fin is bolted
on with a carbon-fiber tube support. The
one-piece stabilizer bolts onto the
fuselage. Included with the model is a
complete set of gear doors that neatly
hides the landing gear and tires when
retracted.
The wing carry-through is a traditional
aluminum tube that extends all the way
out the main landing-gear retract units to
ensure a solid structure to transfer those
hard landing loads. The main landing gear
has an extremely wide track to maximize
ground handling and it does this well. A
trailing-link nose gear is available as part
of the retract accessory kit; again, this
helps with straight, positive ground
tracking.
The provided fuel tanks are custommolded
Kevlar fitted around the inlet
ductwork and nearly centered over the
wing carry-through. This tank design
incorporates baffling to reduce fuel
sloshing. The tanks are Y connected to a
header tank for final feed to the fuel
pump. An optional extended-range fuel
tank is available and can be configured to
hold 1.5-2.1 liters of additional fuel or it
could be used to hold smoke oil for an airshow
performance.
For more information about the
Composite-ARF Lightning, check out the
company’s Web site at www.compositearf.
com. The site even includes the
instruction manual so the customer can
learn much about the model before
purchasing.
The cost varies based on color schemes
but ranges from $2,800 to $3,200. The
retract gear set with wheels and brakes
will add another $949.
The Lightning is a lot of aircraft and
comes complete with many systems!
A new subject is making the rounds
throughout the jet-modeling community:
static electricity and turbine shutdowns. A
strong effort is underway to understand,
explain, and prevent turbine shutdowns
caused by static electricity that usually
happen immediately following takeoff.
This problem appears to be related to the
larger turbines now in use.
An initial theory blamed the problem
on static buildup during takeoff from the
fast-rolling tires, but this appears to have
been debunked. The currently accepted
theory is that fuel flowing through the
airplane is the source of unwanted static
buildup.
The larger engines in use today
consume large volumes of kerosene, and
the fuel flows at high velocity through the
fuel lines. Common practice is to use the
same-size fuel lines regardless of the
turbine’s fuel-flow requirements. I have
used giant-scale-size lines from day one
on the fuel lines inside the tanks and all
the way to the fuel pump, whether it is on
a turbine with only 8 pounds of thrust or
one with as much as 40 pounds of thrust.
The theory is that as the fuel flows at
greater speeds through the fuel lines, static
electricity builds up and is released into
the ECU, causing inadvertent turbine
shutdowns usually early in the flight when
the model is fully laden with fuel, and this
is a bad situation.
Another source of fuel movement is the
use of large Kevlar fuel tanks without
baffling, which allows fuel to slosh around
and create a static-charge buildup.
Current discussions and developments
center on how to dissipate static charges
with conductive fuel lines or fuel tanks
with conductive material. Even fuel
additives in the kerosene are being
considered.
JetCat USA is heavy into investigating
this issue and has some good information
on its Web site: www.jetcatusa.com. I am
sure we will be hearing more about this
subject as additional knowledge and
solutions are developed.
It’s time for me to pack and get on to
flying, so have a good day and see you at
the jet meets.
Edition: Model Aviation - 2007/02
Page Numbers: 123,124,126,128
Also included in this column:
• Composite-ARF’s Lightning
sport jet
• Understanding static-electricity
issues
REPAIR TECHNOLOGY International
(RTI) has introduced the RTI 2800 Special
Edition turbine of its own manufacture.
Carlos Villarreal, the man behind RTI, has
been supporting parts and repair services
for the RAM turbines since that company’s
demise. After years of valuable experience
repairing RAM and JetCat turbines, Carlos
has decided to step into the market with
the RTI 2800.
The RTI 2800 is a 66mm turbine of
conventional layout. It will feature an
inconel combustion chamber, which is
necessary for its long life. The turbine
wheel is of Swiss manufacture and is of
the highest proven quality.
Carlos is applying his years of
experience to fine-tune this engine to
produce a reliable, guaranteed 28 pounds
of thrust. Many manufacturers claim 28
pounds of thrust, but their turbines don’t
produce that figure in the real world. Many
factors affect thrust including temperature,
humidity, and altitude, in addition to
normal production variations. For RTI to
guarantee its thrust rating is a bold step.
From years of testing thrust, I know
this is difficult to do in production. It’s
harder still to deal with the understanding
of the effect altitude density has on
performance, hence our expectations of a
28-pound-thrust turbine at sea level on a
standard day versus a hot, humid Midwest
summer day.
I like this guarantee and hope it
pressures all manufacturers to be realistic
in their claims of thrust ratings as opposed
to the real thrust delivered by turbines.
The RTI 2800 Special Edition will
come with electronics supplied by RJP
Models—a company with many years of
experience producing engine control units
(ECUs) for model turbines. The software
will be open for the modeler to fine-tune
parameters to suit his or her preferences.
Included in the software will be a throttlecurve
adjustment for altitude compensation
when required. Factory settings will
provide a 3.5- to 4.0-second acceleration
time from idle to full throttle—a realistic
figure for a quality turbine in this class.
Chuck Shull’s large, aerobatic Composite-ARF Lightning, designed for a 34-pound-thrust
turbine, with its attractive lines and striking colors.
The Lightning’s flap extends above the
wing when deflected to increase drag and
improve landing-approach accuracy.
Included with the purchase of the RTI
2800 Special Edition is the turbine
engine, a fuel pump, ECU, required
solenoids, and an 1800 mAh six-cell Ni-
Cd battery pack. The cost of this package
is currently set at $3,250. The RTI 2800
can be set up to run on Li-Poly batteries
or NiMH batteries if that is your
preference.
RTI is a full product distributor for
necessary support equipment for your
turbine operations in addition to the repair
service. You can find full information on
its products and services including the
new RTI 2800 Special Edition turbine at
www.rtiturbines.com.
Composite-ARF introduced the
Lightning sport jet early in 2006, and it
has proven to be a popular model. The
Lightning is large and has a conventional
layout with an emphasis on ease of flying
and assembly. Don’t be mislead, though;
this is a serious precision aerobatic model
designed to perform complicated routines.
Construction of the Lightning follows
Composite-ARF’s now-traditional use of
composite structures with balsa and
hardwood for internals and Kevlar and
carbon-fiber reinforcements. This
provides a light, rigid model that is able
to handle the extreme loads of high-speed
flight.
The Lightning follows the hugely
popular Eurosport. It spans 79 inches and
is 102 inches in length. It is a large model
intended to be powered by 160N turbines
or those with 34-pound thrust or greater.
You can expect an empty weight of
roughly 30 pounds, so you will have a
reasonably light wing loading. With great
power-to-weight ratio, this makes for
incredible performance.
Typical of Composite-ARF models, the
Lightning is available in a variety of color
schemes ranging from sport aerobatic to
military. The Jolly Roger scheme makes
for a smart-looking aircraft, while the
Navy version adds some high-visibility
colors to the traditional gray camouflage.
You can’t go wrong with any of them.
This big model with its attractive lines
presents itself well.
Breakdown for transportation of the
Lightning is handled with features such as
the two-piece wing, removable stabilizer,
and removable fin. The nose cone is also
removable.
Access to the interior of the airplane is
through a large canopy hatch on the top
and an extremely large removable bottom
hatch. This lower hatch extends from the
LE of the wing to the LE of the stabilizer,
giving plenty of access to load the turbine
and all those systems we carry.
The Lightning features a unique flap
design that is hinged on the bottom but
extends forward on the top. When
deflected, this arrangement allows the flap
to extend above the upper wing surface to
act as a drag device on top—similar to a
spoiler—while deflecting the air
downward off the bottom surface, similar
to a traditional flap.
This is a neat idea and appears to work
effectively. The flap servo mount is well
thought out and clear of the wheel well;
this makes for a nice installation.
Construction and finish of the
Lightning includes features such as
factory-installed internal ductwork. The
fuselage has traditional formers to stiffen
the airframe and provide hard mounting
points for critical equipment. All control
surfaces are factory hinged—another
convenience for the builder.
As I mentioned earlier, the fin is bolted
on with a carbon-fiber tube support. The
one-piece stabilizer bolts onto the
fuselage. Included with the model is a
complete set of gear doors that neatly
hides the landing gear and tires when
retracted.
The wing carry-through is a traditional
aluminum tube that extends all the way
out the main landing-gear retract units to
ensure a solid structure to transfer those
hard landing loads. The main landing gear
has an extremely wide track to maximize
ground handling and it does this well. A
trailing-link nose gear is available as part
of the retract accessory kit; again, this
helps with straight, positive ground
tracking.
The provided fuel tanks are custommolded
Kevlar fitted around the inlet
ductwork and nearly centered over the
wing carry-through. This tank design
incorporates baffling to reduce fuel
sloshing. The tanks are Y connected to a
header tank for final feed to the fuel
pump. An optional extended-range fuel
tank is available and can be configured to
hold 1.5-2.1 liters of additional fuel or it
could be used to hold smoke oil for an airshow
performance.
For more information about the
Composite-ARF Lightning, check out the
company’s Web site at www.compositearf.
com. The site even includes the
instruction manual so the customer can
learn much about the model before
purchasing.
The cost varies based on color schemes
but ranges from $2,800 to $3,200. The
retract gear set with wheels and brakes
will add another $949.
The Lightning is a lot of aircraft and
comes complete with many systems!
A new subject is making the rounds
throughout the jet-modeling community:
static electricity and turbine shutdowns. A
strong effort is underway to understand,
explain, and prevent turbine shutdowns
caused by static electricity that usually
happen immediately following takeoff.
This problem appears to be related to the
larger turbines now in use.
An initial theory blamed the problem
on static buildup during takeoff from the
fast-rolling tires, but this appears to have
been debunked. The currently accepted
theory is that fuel flowing through the
airplane is the source of unwanted static
buildup.
The larger engines in use today
consume large volumes of kerosene, and
the fuel flows at high velocity through the
fuel lines. Common practice is to use the
same-size fuel lines regardless of the
turbine’s fuel-flow requirements. I have
used giant-scale-size lines from day one
on the fuel lines inside the tanks and all
the way to the fuel pump, whether it is on
a turbine with only 8 pounds of thrust or
one with as much as 40 pounds of thrust.
The theory is that as the fuel flows at
greater speeds through the fuel lines, static
electricity builds up and is released into
the ECU, causing inadvertent turbine
shutdowns usually early in the flight when
the model is fully laden with fuel, and this
is a bad situation.
Another source of fuel movement is the
use of large Kevlar fuel tanks without
baffling, which allows fuel to slosh around
and create a static-charge buildup.
Current discussions and developments
center on how to dissipate static charges
with conductive fuel lines or fuel tanks
with conductive material. Even fuel
additives in the kerosene are being
considered.
JetCat USA is heavy into investigating
this issue and has some good information
on its Web site: www.jetcatusa.com. I am
sure we will be hearing more about this
subject as additional knowledge and
solutions are developed.
It’s time for me to pack and get on to
flying, so have a good day and see you at
the jet meets.
Edition: Model Aviation - 2007/02
Page Numbers: 123,124,126,128
Also included in this column:
• Composite-ARF’s Lightning
sport jet
• Understanding static-electricity
issues
REPAIR TECHNOLOGY International
(RTI) has introduced the RTI 2800 Special
Edition turbine of its own manufacture.
Carlos Villarreal, the man behind RTI, has
been supporting parts and repair services
for the RAM turbines since that company’s
demise. After years of valuable experience
repairing RAM and JetCat turbines, Carlos
has decided to step into the market with
the RTI 2800.
The RTI 2800 is a 66mm turbine of
conventional layout. It will feature an
inconel combustion chamber, which is
necessary for its long life. The turbine
wheel is of Swiss manufacture and is of
the highest proven quality.
Carlos is applying his years of
experience to fine-tune this engine to
produce a reliable, guaranteed 28 pounds
of thrust. Many manufacturers claim 28
pounds of thrust, but their turbines don’t
produce that figure in the real world. Many
factors affect thrust including temperature,
humidity, and altitude, in addition to
normal production variations. For RTI to
guarantee its thrust rating is a bold step.
From years of testing thrust, I know
this is difficult to do in production. It’s
harder still to deal with the understanding
of the effect altitude density has on
performance, hence our expectations of a
28-pound-thrust turbine at sea level on a
standard day versus a hot, humid Midwest
summer day.
I like this guarantee and hope it
pressures all manufacturers to be realistic
in their claims of thrust ratings as opposed
to the real thrust delivered by turbines.
The RTI 2800 Special Edition will
come with electronics supplied by RJP
Models—a company with many years of
experience producing engine control units
(ECUs) for model turbines. The software
will be open for the modeler to fine-tune
parameters to suit his or her preferences.
Included in the software will be a throttlecurve
adjustment for altitude compensation
when required. Factory settings will
provide a 3.5- to 4.0-second acceleration
time from idle to full throttle—a realistic
figure for a quality turbine in this class.
Chuck Shull’s large, aerobatic Composite-ARF Lightning, designed for a 34-pound-thrust
turbine, with its attractive lines and striking colors.
The Lightning’s flap extends above the
wing when deflected to increase drag and
improve landing-approach accuracy.
Included with the purchase of the RTI
2800 Special Edition is the turbine
engine, a fuel pump, ECU, required
solenoids, and an 1800 mAh six-cell Ni-
Cd battery pack. The cost of this package
is currently set at $3,250. The RTI 2800
can be set up to run on Li-Poly batteries
or NiMH batteries if that is your
preference.
RTI is a full product distributor for
necessary support equipment for your
turbine operations in addition to the repair
service. You can find full information on
its products and services including the
new RTI 2800 Special Edition turbine at
www.rtiturbines.com.
Composite-ARF introduced the
Lightning sport jet early in 2006, and it
has proven to be a popular model. The
Lightning is large and has a conventional
layout with an emphasis on ease of flying
and assembly. Don’t be mislead, though;
this is a serious precision aerobatic model
designed to perform complicated routines.
Construction of the Lightning follows
Composite-ARF’s now-traditional use of
composite structures with balsa and
hardwood for internals and Kevlar and
carbon-fiber reinforcements. This
provides a light, rigid model that is able
to handle the extreme loads of high-speed
flight.
The Lightning follows the hugely
popular Eurosport. It spans 79 inches and
is 102 inches in length. It is a large model
intended to be powered by 160N turbines
or those with 34-pound thrust or greater.
You can expect an empty weight of
roughly 30 pounds, so you will have a
reasonably light wing loading. With great
power-to-weight ratio, this makes for
incredible performance.
Typical of Composite-ARF models, the
Lightning is available in a variety of color
schemes ranging from sport aerobatic to
military. The Jolly Roger scheme makes
for a smart-looking aircraft, while the
Navy version adds some high-visibility
colors to the traditional gray camouflage.
You can’t go wrong with any of them.
This big model with its attractive lines
presents itself well.
Breakdown for transportation of the
Lightning is handled with features such as
the two-piece wing, removable stabilizer,
and removable fin. The nose cone is also
removable.
Access to the interior of the airplane is
through a large canopy hatch on the top
and an extremely large removable bottom
hatch. This lower hatch extends from the
LE of the wing to the LE of the stabilizer,
giving plenty of access to load the turbine
and all those systems we carry.
The Lightning features a unique flap
design that is hinged on the bottom but
extends forward on the top. When
deflected, this arrangement allows the flap
to extend above the upper wing surface to
act as a drag device on top—similar to a
spoiler—while deflecting the air
downward off the bottom surface, similar
to a traditional flap.
This is a neat idea and appears to work
effectively. The flap servo mount is well
thought out and clear of the wheel well;
this makes for a nice installation.
Construction and finish of the
Lightning includes features such as
factory-installed internal ductwork. The
fuselage has traditional formers to stiffen
the airframe and provide hard mounting
points for critical equipment. All control
surfaces are factory hinged—another
convenience for the builder.
As I mentioned earlier, the fin is bolted
on with a carbon-fiber tube support. The
one-piece stabilizer bolts onto the
fuselage. Included with the model is a
complete set of gear doors that neatly
hides the landing gear and tires when
retracted.
The wing carry-through is a traditional
aluminum tube that extends all the way
out the main landing-gear retract units to
ensure a solid structure to transfer those
hard landing loads. The main landing gear
has an extremely wide track to maximize
ground handling and it does this well. A
trailing-link nose gear is available as part
of the retract accessory kit; again, this
helps with straight, positive ground
tracking.
The provided fuel tanks are custommolded
Kevlar fitted around the inlet
ductwork and nearly centered over the
wing carry-through. This tank design
incorporates baffling to reduce fuel
sloshing. The tanks are Y connected to a
header tank for final feed to the fuel
pump. An optional extended-range fuel
tank is available and can be configured to
hold 1.5-2.1 liters of additional fuel or it
could be used to hold smoke oil for an airshow
performance.
For more information about the
Composite-ARF Lightning, check out the
company’s Web site at www.compositearf.
com. The site even includes the
instruction manual so the customer can
learn much about the model before
purchasing.
The cost varies based on color schemes
but ranges from $2,800 to $3,200. The
retract gear set with wheels and brakes
will add another $949.
The Lightning is a lot of aircraft and
comes complete with many systems!
A new subject is making the rounds
throughout the jet-modeling community:
static electricity and turbine shutdowns. A
strong effort is underway to understand,
explain, and prevent turbine shutdowns
caused by static electricity that usually
happen immediately following takeoff.
This problem appears to be related to the
larger turbines now in use.
An initial theory blamed the problem
on static buildup during takeoff from the
fast-rolling tires, but this appears to have
been debunked. The currently accepted
theory is that fuel flowing through the
airplane is the source of unwanted static
buildup.
The larger engines in use today
consume large volumes of kerosene, and
the fuel flows at high velocity through the
fuel lines. Common practice is to use the
same-size fuel lines regardless of the
turbine’s fuel-flow requirements. I have
used giant-scale-size lines from day one
on the fuel lines inside the tanks and all
the way to the fuel pump, whether it is on
a turbine with only 8 pounds of thrust or
one with as much as 40 pounds of thrust.
The theory is that as the fuel flows at
greater speeds through the fuel lines, static
electricity builds up and is released into
the ECU, causing inadvertent turbine
shutdowns usually early in the flight when
the model is fully laden with fuel, and this
is a bad situation.
Another source of fuel movement is the
use of large Kevlar fuel tanks without
baffling, which allows fuel to slosh around
and create a static-charge buildup.
Current discussions and developments
center on how to dissipate static charges
with conductive fuel lines or fuel tanks
with conductive material. Even fuel
additives in the kerosene are being
considered.
JetCat USA is heavy into investigating
this issue and has some good information
on its Web site: www.jetcatusa.com. I am
sure we will be hearing more about this
subject as additional knowledge and
solutions are developed.
It’s time for me to pack and get on to
flying, so have a good day and see you at
the jet meets.