Figure 3-43. Cruise throttle control and ignition switches.
Canister Rocket
Ballistic Parachute System
Figure 3-41. Located under the pilot’s legs, the canister will blow
through the break-away panel in the cowling.
Figure 3-42. Canister mounted under engine.
Flight Deck
The fl ight deck is where the pilot and passenger sit. It is
typically a tandem seating with the pilot in front and the
passenger in back. When the WSC aircraft is used for
instruction, the instructor typically sits in back and must have
access to the fl ight controls.
The pilot in the front has ground and fl ight controls. The
right foot controls a foot throttle and the left foot controls
the brake. This is similar to throttle and brake controls on an
automobile. The feet also control ground steering by moving
the front fork with the foot pedals. A foot throttle and foot
brake can be added to optional ground steering control for
use by an instructor sitting in back.
A hand cruise throttle is typically used when the pilot can
set it and it stays set. This cruise throttle is usually in a
position where the instructor in the back seat can also operate
it. [Figures 3-43]
The wing fl ight control bar is in a position at chest height for
the pilot in the front seat. Additional extensions are added
for a passenger or instructor to use if seated in the back seat.
[Figure 3-7]
Ignition switches are sometimes included in the cruise
control throttle housing or as a separate set of switches. If
a WSC is used for instruction, the ignition switches should
be within reach of the instructor sitting in the back seat.
[Figures 3-43]
The ballistic parachute handle must be accessible for use
when needed but not put in a position where it could be
accidentally deployed. Some WSC aircraft have two handles,
one for the front and one for the back. Additional controls
for starting, such as the choke or enricher, must be accessible
to the pilot.
Dashboards and Instrument Panels
The instrument panel is in front of the pilot and provides
engine, fl ight, navigation, and communications information.
The pilot is responsible for maintaining collision avoidance
with a proper and continuous visual scan around the aircraft,
as well as monitoring the information available from the
instrument panel. The pilot must process the outside cues
along with the instrumentation throughout the fl ight for a
sound decision-making process.
The ignition switches, which may be located on the
instrument panel or within the instructors reach for WSC
used for instruction, has two positions: ON, which allows
power to make contact with the spark plugs, or OFF, which is
a closed switch to GROUND and removes the power source
from the spark plugs. Typically, WSC engines have two
spark plugs per cylinder, two switches, and two completely
separate ignition systems. Some single-place WSCs with
smaller engines have only one spark plug per cylinder, one
ignition switch, and a single ignition system.
Figure 3-44. Basic analog flight and engine instruments.
Engine
Hours
Starter
Airspeed
CHT
RPM
EGT
GPS
Master
Altitude
Accessories Plug
For example, for a two-stroke liquid-cooled engine, the
manufacturer may require instrumentation to monitor engine
exhaust gas temperatures (EGT), water temperatures, and
revolutions per minute (rpm). Additionally, for a four-
stroke engine, the manufacturer may additionally require oil
temperature and pressure gauges. For a simple two-stroke air-
cooled engine, the manufacturer’s requirement may be EGT,
cylinder head temperature (CHT) and rpm instrumentation.
Generally, most electrical or engine controls are located on
the dashboard unless required to be reached by the instructor
for fl ight instruction.
Dashboards are as varied as the manufacturers and the
purpose of the aircraft, from simple to complex. Classical
analog gauges are common, but digital instruments are
becoming more popular with light-sport aircraft (LSA).
Overall, no instrumentation is required for E-LSA, but for
S-LSA an airspeed indicator is usually required, and engine
manufacturers require certain instruments be installed on the
aircraft to monitor the performance of the particular engine.
Flight Instruments
The specifi c theory of operation and details of instruments is
covered in the Pilot’s Handbook of Aeronautical Knowledge,
and is a prerequisite to this section on fl ight instruments. The
altimeter is the most important fl ight instrument and should
be on every WSC aircraft. It is used to maintain the proper
altitude at airports, during cruise, and provides other aircraft
position information for the safety of all.
The vertical speed indicator (VSI) is one tool to assist the pilot
with the performance of the aircraft. The airspeed indicator
(ASI) is used to optimize performance of the aircraft, compare
predicted to actual performance, and to operate within the
limitations of the aircraft.
Navigation Instruments
A global positioning system (GPS) is typically used as a
navigation and fl ight aid for most WSC aircraft. A magnetic
compass is commonly used as a primary navigation system
or as a backup when a GPS system is used.
Engine Instruments
There is a variety of engine instruments that are used. The
most basic is the engine rpm, which determines the power
of the engine. Specifi c engine instruments are discussed in
the powerplant section.
Instrument Panel Arrangements
Instrument panels vary greatly from the basic to the complex.
Figure 3-44 depicts a standard instrument panel supplied
by the manufacturer with a portable GPS added in the
middle. Electrical components are neatly arranged along the
top. Large analog airspeed (left) and altitude (right) fl ight
instruments are installed in the middle with the portable
GPS installed between the two. The bottom stack consists
of the basic engine instruments for a simple two-stroke air-
cooled engine: RPM for power (top), CHT (middle) and
EGT (bottom).
A more advanced analog panel with a user radio and GPS
added is shown in Figure 3-45. Airspeed, vertical speed
indicator, and altitude large fl ight instruments are along
Figure 3-46. Instrument hybrid—analog airspeed and compass
indicator with separate digital instruments.
Figure 3-47. Digital instrument panel.
Magnetic Compass
Radio Communications
System Electric
Switches
Transponder
Ignition
Main Electric Switch
Digital Panel for
Flight Instruments
Engine Instruments
GPS
Flight
Timer
Radio
Airspeed
CHT
RPM
EGT
VSI
Altitude
Magnetic
Compass
GPS
Phone
Volts
Master
Strobe
Figure 3-45. Full analog instruments.
Oil Pressure
Master ElecAirspeed
Volts
Fuel
Level
EGT
GPS
VSI
CHT
Altitude
Oil
Temp.
Radio
Strobe
Direction
the top. A navigational gyro is in the middle of the panel.
The bottom row consists of four-stroke engine instruments,
electrical and remote fuel gauge. The user installed radio and
GPS complete a well equipped instrument panel. A hybrid
panel of analog, digital, and portable instruments is shown
in Figure 3-46.
The integrated digital panel does provide more options
in a smaller space. One panel can now have aircraft
performance screens, engine systems screens, navigation
screens, communications screens, attitude indicator, and any
combination of these. [Figure 3-47]
Figure 3-49. Flight deck and aircraft radio communications system example.
Battery
Head Phone 2—
Passenger
Head Phone 1—Pilot
P.T.T. 1—Push To Talk
P.T.T. 2 (optional)
used for
instructor
during training
Head phones disconnect
Radio
Fuse
Optional Device
music or cell phone
Some systems require an intercom
box for headphones to plug into.
OFF
1 HeadPhone
2 HeadPhone
Head Phones
Figure 3-48. Basic pilot-to-passenger communication system.
Communications
There are three types of communications systems used in
WSC aircraft:
1. Communications between the pilot and passenger
while inside the aircraft.
2. Aircraft radio communications with other aircraft and
control towers.
3. Radar position indicator communications from the
WSC aircraft to control towers (transponder).
Easy and clear communications between the pilot and
passenger, or between the instructor and student inside
the fl ight deck is important for the safety and enjoyment
of both. Modern communications systems have advanced
noise canceling systems in headphones and microphones to
reduce engine noise and blast of air. Each system is unique,
and the quality of the sound and noise canceling capability
of the system varies. Some use voice-activated systems in
which headphones activate only when someone is speaking
into the microphone; others have a steady state in which
there is no additional control of the voice activation. Since
there is a large difference in systems available, it is best to
test systems to determine what is best for the WSC aircraft
being fl own. [Figure 3-48]
An aircraft radio is required for fl ying in any tower controlled
airspace. Using a radio is not required at airports without a
control tower but it is recommended for the safety of self,
passengers, pilots in the air, and people/property on the
ground. To broadcast to a tower or other aircraft, press a
Push To Talk (PTT) button. A complete fl ight deck radio and
accessory system schematic is shown in Figure 3-49.
A radar signal receiver/transmitter system is required at busy
commercial airports (Classes C and B) and at altitudes above
10,000 feet mean sea level (MSL) (unless the aircraft was
certifi ed without an electrical system to power the unit). This
is known as a Mode C transponder that sends a signal giving
the control tower an exact location and altitude of aircraft.
[Figure 3-47]
Powerplant System
The powerplant system is composed of the fuel system,
engine, gearbox, and propeller. Here we will point out the
basic components of these systems with their function and
details covered in Chapter 4, Powerplant System.
Engine Gearbox
Figure 3-52. Engine gearbox.
Figure 3-50. Fuel tank with visible fuel quantity.
Visible Fuel Level
Fuel Tank
Fuel fill
Figure 3-51. Fuel fill to fuel tank under passengers seat.
Fuel System Components
The WSC aircraft is equipped with fuel tanks usually ranging
in capacity from 5 to 20 gallons. As with any aircraft,
knowing how much fuel the tank holds is crucial to fl ight
operations. The LSA defi nition has no limitations on the size
of the fuel tank, unlike its ultralight vehicle predecessor.
Generally, the fuel tank is located close to the CG, so fuel
burn does not affect the balance of the carriage. Some fuel
tanks are clear for visual inspection of the amount of fuel
on board [Figure 3-50], while others have tanks that are not
visible and require fuel level probes for instrument panel
indication of fuel. [Figure 3-51]
Fuel lines exit the fuel tank, and may incorporate a primer
bulb, fuel fi lters, fuel pump, and/or a primer system, all of
which must be integrated into the carriage. A fuel venting
system is also required, which can be a hole in the fuel fi ller
or lines running to vent at an appropriate location.
A fuel shut-off valve may be installed and can be located
anywhere in the fuel line. Some designs have a fuel tank sump
drain valve to remove water and solid contaminants.
Engine and Gearbox
The typical WSC aircraft engine can be two or four stroke,
liquid or air cooled, and normally ranges from 50 to 100
horsepower. Some engines have electric starters and some
have pull starters. Most WSC aircraft engines have reduction
drives that, when attached, reduce the propeller rpm from ½
to ¼ the engine rpm. [Figure 3-52]
A signifi cant amount of the total aircraft empty weight
is determined by the powerplant (engine, gearbox, and
propeller) and mounting confi guration. When trailering
the WSC aircraft over bumpy terrain or over long trips,
the bouncing of the carriage in the trailer can put extreme
stress on this mounting system. In addition, repeated hard
landings of the carriage can also stress the welds of the engine
mount. Consistent detailed inspections of the engine mount
should be an important part of every prefl ight and postfl ight
inspection.
The powerplant systems are as varied as the WSC aircraft
they power. Modern technology has allowed these systems
to become lighter, quieter, more efficient, and, most
importantly, dependable.
The Propeller
Propellers are “power converters” that change the engine
horsepower into thrust. Thrust is the force that propels the
aircraft through the air by pushing the WSC aircraft forward.
Aerodynamically speaking, a propeller is a rotating airfoil
and the same principles that apply to the wing applies to the
propeller, except the propeller provides a horizontal force
of thrust.
Figure 3-54. Three-blade propeller.
Figure 3-53. Four-blade propeller.
Propellers typically consist of two, three, or four blades.
[Figures 3-53 and 3-54] Propellers can be ground adjustable
or fi xed pitch. Variable pitch fl ight propellers are not allowed
on LSA. The pitch should be properly set for your WSC
aircraft to provide the recommended rpm of the engine at
full power. The POH should be consulted if there is any
question about the propeller rpm and adjusting or replacing
the propeller. Propellers are specifi cally matched to the
engine power, gear reduction and speed range of the aircraft.
Therefore, not just any propeller may be put on any engine.
The POH requires specifi c propellers that are matched for
each aircraft.
As with an airplane propeller, the WSC aircraft propeller
turns at such high speeds that it becomes invisible when in
motion. The dangers of a turning propeller require every
pilot to maintain the highest level of safety and respect for
the consequences of body parts, pets, and debris coming
in contact with a rotating propeller. Debris on the takeoff/
landing fi eld is a danger to the propeller, as well as to the
people who may be in the prop-wash area behind or on the
side of the propeller. Stones, small pieces of metal, and
sticks can become dangerous projectiles if kicked into the
propeller during start-up, taxi, takeoff, and landing. Just as
with any airframe or wing component of a WSC aircraft, if the
propeller becomes damaged, nicked, or dinged, the aircraft’s
performance can be greatly affected. Some pilots elect to use
tape or rock defl ector guards to protect the leading edge from
rock/debris damage. Regardless, taking proper care of the
propeller is as critical as proper engine and wing care.
Chapter Summary
Components and systems consist of two primary
subassemblies: wing and carriage. The main wing component
is the frame, which is composed of the leading edges, keel,
crossbar, and control frame. The typical wing frame has lower
wires and upper wires with a king post. The strutted version
has wing struts and no upper rigging. The frame is designed
so the outboard leading edges fl ex, and it also has a control
system that allows the keel to move side to side relative to the
leading edges for roll control. The sail is designed specifi cally
for the frame with battens and leading edge stiffner provide
the rigid airfoil shape of the sail.
The carriage is separate from the wing. Different wings can be
put on the same carriage at separate times for different types
of fl ying (example: large wing is used for fl ying low and slow
where a small wing can be used for fl ying fast and long cross-
country missions). As discussed in Chapter 2, Aerodynamics,
each wing must be approved by the manufacturer to go on
a specifi c carriage.
Main carriage components are the mast, carriage keel, front
tube, and engine mount. This structure houses the fl ight deck,
powerplant, and landing gear. The carriage structure also
houses system components such as the electrical system,
ballistic parachute, and fuel tank. The fl ight deck is the heart
of the carriage providing pilot systems for communications,
navigation, engine/flight/navigation instruments, and
electrical controls.