C-172 Systems Flashcards
What type of engine do we have?
- Textron-Lycomming IO-360-L2A
- rated 180 BHP at 2700 RPM
- it is 4 cylinder, normally aspirated, direct drive, air-cooled, and horizontally opposed
What does normally aspirated mean?
- the air intake is not boosted with a supercharger or turbocharger
What does direct drive mean?
- the propeller is directly connected to the crankshaft
What does air-cooled mean?
- the engine has cooling fans that circulate air, but is not liquid cooled
What does horizontally opposed mean?
- the cylinders are lying flat
What are the primary flight controls?
- ailerons, rudder, and elevator
How are primary flight controls operated?
- manually operated through cables, pullies, and mechanical linkages
What type of ailerons do we have?
- differential ailerons
How do differential ailerons work?
- the upward deflected aileron is deflect more than the downward deflected aileron
- upward aileron produces more lift to help reduce adverse yaw
What type of flaps do we have?
- slotted flaps
How do slotted flaps work?
- high pressure air below the wing flows through the slot and meets the low pressure air above the wing
- delays airflow separation producing less drag
How are the flaps operated?
- manually operated, electrically powered
What are the secondary flight controls?
- trim
What type of propeller do we have?
- fixed pitch
How long is the propeller?
- 76 inches
What type of landing gear do we have?
- tricycle landing gear with a steerable nose wheel and 2 main gears
How does shock absorption work?
- nose gear shock strut
- spring steel struts on the mains
How does braking work?
- each wheel has a hydraulically actuated disc brake
- the brakes are connected to a master cylinder attached the the rudder pedals
What color is hydraulic fluid?
- red
How much fuel can we carry?
- 56 gallons total, 2 26.5 gallon vented fuel tanks
How does fuel go from the tanks to the engine?
- gravity fed
- fuel tank > fuel selector > fuel reservoir tank > electric fuel pump > fuel shutoff valve > strainer > engine driven fuel pump > fuel/air control unit > cylinder
How does the G1000 get fuel information?
- fuel sensors in each tank
What type of oil system do we have?
- wet sump
What is the oil capacity?
- 8 quarts
What does wet sump mean?
- oil pump draws fuel from the sump and distributes oil to the engine
- after passing through the engine it goes back to the sump
What are the functions of engine oil?
- cleans
- cools
- hydraulic action
- corrosion protection
How does a 4-stroke engine work?
- Intake (intake valve opens, fuel/air mixture enter combustion chamber)
- Compression (piston moves up, compressing fuel/air mixture)
- Power (sparkplugs ignite fuel/air mixture creating explosion and forcing piston down)
- Exhaust (exhaust valve opens, letting exhaust gas out of cylinder)
How many fuel pumps do we have?
- 2
- electric fuel pump
- engine-driven fuel pump
What does the alternator control unit (ACU) do?
- automatically disconnects the alternator by disconnecting the “ALT FLD” circuit breaker in case of over-voltage
What does the “LOW VOLTS” annunciator mean?
- voltage falls below 24.5V
- alternator is not supplying the required power for the electrical system
What type of electrical system do we have?
- 28 volt DC belt-driven alternator, a 24-volt main battery, and a standby battery that provides 30 minutes of use to the essential bus
What is on the essential bus?
- PFD, ADC/AHRS, COM1, NAV1, STBY indicator lights, STBY BATT
How many buses does the electrical system have?
- 6
What do circuit breakers do?
- protects electrical equipment from over-voltage and power surges
How do circuit breakers work?
- they are designed to carry a specific electrical load, if too much current flows through the circuit breaker the conductor heats up and expands, popping the circuit breaker
What does DC mean?
- direct current
- current flows in one direction and it can be stored
What type of avionics do we have?
- G1000
How does a G1000 operate?
- Line replaceable units (LRU’s)
- Air data computer (ADC)
- Attitude and heading reference system (AHRS)
How does the ADC work?
- provides information for the pitot/static instruments (ASI, ALT, VSI)
- information from the pitot tube and static port is sent to the ADC which computes the information and creates a digital display
How does the AHRS work?
- provides information for the gyroscopic instruments
- solid state (doesn’t move)
- electromagnetic mechanical gyroscopes (measures systems angular rate)
- accelerometer (measures acceleration, pitch and roll)
- magnetometer (measures difference between Earth’s magnetic field, yaw)
Where is the magnetometer located?
- the left wing panel
Where is the AHRS located?
- the tail cone
What de-icing and anti-icing systems do we have?
- pitot heat, fuel vent location, alternate induction air trap door, alternate static air, and heated windscreen
What would happen if the pitot tube becomes blocked?
- ASI will show zero
What would happen if the pitot tube and drain hole becomes blocked?
- ASI will act as an altimeter
What would happen if the static port becomes blocked?
- ASI will show high in climb and low in descent
- ALT will be frozen
- VSI will show zero
What would happen if you use alternate static air?
- ASI faster than actual
- ALT higher than actual
- VSI shows momentary climb
What should you do if a circuit breaker trips?
- wait about 60 seconds before pushing it back in
- if it trips more than twice, do not reset it
What are the engine starting restrictions?
- do not crank for more than 10 seconds, allow 20 seconds between each crank, and repeat no more than 6 times
If the engine quits during the magneto check during the run-up, what should you do?
- throttle to idle and do not return magnetos to both position
If you notice a drop in oil pressure and rise in oil temperature, what is happening?
- engine will likely die soon
- reduce power and find a suitable place to land
If you see the high volts annunciator come on, what is happening?
- ACU is inoperative
If you see the low volts annunciator come on, what is happening?
- the alternator is malfunctioning
What do balance weights do?
- shifts the control surface’s CG closer to the hinge line to create a shorter arm
- shorter arm reduced tendency of fluttering
How do frise ailerons work?
- protrudes slightly into the airstream, increasing drag to counter adverse yaw
How do ailerons work?
- produce a rolling moment around the longitudinal axis
- ## increases lift on one wing while decreasing lift on the other
How do ailerons work?
- produce a rolling moment around the longitudinal axis
- increases lift on one wing while decreasing lift on the other causing the airplane to bank
What is adverse yaw?
- tendency for the aircraft to yaw in the opposite direction of the turn
- during left turn, right aileron is deflected downward creating more lift and more drag, the increase in drag on outside wing causes nose to yaw outside the turn
How does the elevator work?
- controls the pitch up and pitch down motion about the lateral axis
- when pulling the yoke back, the elevator is deflected upward, decreasing the camber of the horizontal stabilizer, creating a downward aerodynamic force which causing the tail to drop and the nose to raise
What is the primary purpose of the horizontal stabilizer?
- creates a tail downforce to provide longitudinal stability
How does the rudder work?
- when the rudder is deflected, it creates an aerodynamic moment around the CG and yaws the aircraft
What is the purpose of primary flight controls?
- provide control of the aircraft about the longitudinal, lateral, and vertical axis
What is the purpose of the secondary flight controls?
- supplement the primary flight controls
How does trim work?
- trim tab moves opposite the elevator to create an equal but opposite moment
What do flaps do?
- increases the camber of the wing, increasing lift and drag, and reduced stall speed
- allows you to fly a steeper approach angle
What does the fuel/air control unit do?
- meters fuel flow according to measured airflow entering the engine, evenly distributes the fuel to each cylinder
What does the fuel/air control unit do?
- meters fuel flow according to measured airflow entering the engine, evenly distributes the fuel to each cylinder
Why are the fuel tanks vented?
- maintains ambient pressure and prevents the creation of a vacuum that would restrict correct fuel flow to the engine
What does the fuel return line do?
- returns from the fuel/air control unit back to the fuel reservoir
- prevents the formation of vapor lock
What does the “HIGH VOLTS” annunciator mean?
- volts exceed 32 volts
- alternator control unit has failed, electrical system will likely catch on fire
What is the primary purpose of the vertical stabilizer?
- weathervane the aircraft w/ the relative wind
What is the primary purpose of the vertical stabilizer?
- weathervane the aircraft w/ the relative wind
What is the primary purpose of the rudder?
- counter adverse yaw, maintain coordination
What does the shimmy damper do?
- prevent rapid unwanted movement of the nosewheel (speed wobbles)
