Unit 3 Flashcards
Measure of the force in an electrical system that causes current flow; measure of EMF
voltage
typical voltage
12V or 24V
Measure of electricity through a conductor
current
unit of current
amps
end of battery that electrons are attracted to
positive terminal
unit of resistance
ohm
what is resistance?
the “friction” an electron encounter as it flows
EMF must be required
which of the following best described the contributing factors to thermal runaway in a nickel-cadmium battery installed in an aircraft?
low internal resistance intensified by high cell temperatures and a high current discharge/charge rate in a constant potential charging system
what do rectifiers do
AC to DC
what do rectifiers have
transformer, stack, and cabinet
what do inverters do
increase DC voltage, then DC to AC
how is electrical energy transferred from one circuit to another without any connections?
induction
how is the voltage output of an alternator regulated?
controlling the voltage output of the DC exciter
solid state transistor and a “zener diode” to regulate voltage
purpose of circuit breakers
designed to protect the circuit from damagingly high levels of current flow
tell me about DC
single direction
constant polarity
changes magnitude when current turns on and off
tell me about AC
direction of current changes
easy to generate
easily stepped up/down with transformers
with an electromagnet, what affects the strength?
winding a coil around a soft iron core
where to find lead acid batteries
piston
NiCad CONS
low internal resistance
long life
expensive
prone to thermal runaway
where to find NiCad batteries
turbine
what is useful load
crew, usable fuel, passengers, and cargo
independent braking system
pressure only as great as foot pressure applied
boosted brakes
actuating system that augments force with hydraulic pressure
aircraft with boosted brakes
medium to large aircraft that do not require a full power system
power brakes
use hydraulic system as source of power to apply the brakes
aircraft with power brakes
large and high performance aircraft
expander tube brakes
1930s-1950s
lightweight, low-pressure brakes
single disc brakes
friction to both sides of disc
aircraft with single disc brakes
small, light aircraft
aircraft with multiple disc brakes
large, heavy
aircraft with segmented rotor
high performance
purpose of torque links
wheel alignment
movement
prevents over extension
function of oleo strut
absorbs shock of landing with hydraulic fluid
when an air/oil type of landing gear shock strut is used, the initial shock of landing is cushioned by
the fluid being forced through a metered opening
purpose of chines
deflect water away from fuselage
types of hydraulic fluid
vegetable base
mineral base
synthetic, phsophate-ester
color of veggie base
blue
color or mineral base
red
color of phosphate- ester
purple clear
vegetable base hydraulic fluid
least used
oldest
mineral hydraulic fluid
common in most aircraft
phosphate-ester hydraulic fluid
skydrol
fire resistant
used in WW2
how is fuel flow measured in fuel-injected engines
measure the pressure drop across the fuel injector nozzles
what does a manifold pressure gauage indicate
absolute pressure inside induction system
what does engine pressure ratio measure
differential pressure between tailpipe total pressure and compressor inlet total pressure
how does a turbine tach indicate
reads RPM of low compressor and high pressure, and gives a percentage
what is the purpose of an EGT gauge
measures the temperature of the exhaust gas
indicates combustion efficiency
monocoque
hardly any internal framework
semi-monocoque
internal arrangement of formers and stringer to provide additional rigidity and strength to the skin
airfoil
shape of wing at any cross section
angle of incidence
determined by manufacturer
angle between chord line and reference axis
center of lift
point where lifting forces are concentrated
center of gravity
point where weight forces are concentrated
CG and CP relationship
CG forward of CP
stall strips
cause wing to stall in non-critical locations before it normally would
servo tabs
small-hinged device installed to assist movement
relationship between alternator and battery
alternator spins and creates electricity for the battery
seminole circuit breaker popping
tripped circuit breakers should be reset only if the affected system/component is considered essential for safety of flight
voltage and amperage
two belt driven 28V, 65 amp alternators
13.6 amp-hour, 24V battery
stops flow of current to the gear pump on the Seminole when on ground
squat switch
stops the flow of current to the gear pump when gear is fully retracted
pressure switch
“CHECK GEAR” CAS message causes
- gear not down and locked and manifold pressure below 14”
- gear position UP and airplane on the ground
- gear not down and locked and flaps are extended 2/3rd notch
empennage of Seminole
vertical stabilizer
all-moveable horizontal stabilator
rudder
flaps on Seminole
flaps on wings
anti-servo tab mounted on trailing edge
