Systems Flashcards
Draw the C172 FUEL Diagram
- 53 gal Usable; 56 gal total (28 each side)
- 13 fuel sumps; 5 each side, 3 under engine cowling
- 3 Vents (1 under left wing, 1 under each fuel cap)
- fuel is supplied via Gravity
Draw & explain the C172 Electrical Diagram
- 28 volt DC electrical system; 24 volt battery
- 60 AMP alternator
- Failure of the alternator is indicated by a low voltage annunciator and a negative reading on the main battery ammeter, if this occurs run the checklist
- Volts (pressure of the pump moving water); Amps (current or flow rate of the water)
- Volts x Amps = Watts
List and Describe the C172 electrical bus (EEEBCAA)
E - Electrical bus #1: Lights (Bcn, landing, cabin), Flaps, electric fuel pump
E - Electrical bus #2: Lights (strobes, NAV, Panel, taxi, Recog), Pitot Ht
E - Essential bus: Comm 1, NAV 1, PFD, ADC, AHRS, STDBY lights
B - Battery bus: powers all bus
C - Cross feed bus: Ties all components together
A - AVI #1: PFD, ADC, AHRS, NAV 1
A - AVI #2: MFD, Transponder, Comm 2, NAV 2, Audio
Cessna 172 Skyhawk Engine (LHAND)
L - Lycoming (O-360, 4 cylinder, 360 cubic inch)
H - Horizontally opposed (pistons oppose each other)
A - Air cooled
N - Normally Aspirated (No turbo or supercharger)
D - Direct Drive (crank shaft connected directly to the propeller)
How many magnetos, spark plugs, alternators, fuel sumps, fuel vents, vacuum pump?
Magnetos = 2
Spark plugs = 8 (2 per cylinders, 4 cylinders)
Alternator = 1 (60 Amps, belt driven)
Fuel Sumps = 13 (5 ea wing, 3 under engine cowling)
Fuel vents = 3 (2 in each cap, 1 on the left wing)
Vaccum pumps = 2 (6pack),
1 (g1000s)
When does Carburetor Icing occur?
1) Visible moisture (clouds)
2) -5° to 20° C or (20° to 70° F)
What causes carburetor icing and what is the solution?
Cause = high air velocity through the venturi and the absorption of the heat from this air by vaporization of the fuel
Solution = turn on carburetor heat and adjust mixture for maximum smoothness
What are circuit breakers?
Circuit breakers has a piece of metal that once heated, it will expand and pop out (circuit breakers pop). Wait 2-5 minutes before re-setting the CB by pushing it in ONE time only
Draw the C172 Vacuum diagram
Describe the C172 landing gear
1) Fixed tricycle gear type
2) Main gear composed of tubular steel springs
3) Nosewheel is fitted w/ oleo (air&oil) struts; absorbs shock to dampen load on airframe
4) Shimmy dampener to help with oscillation when moving on the ground
Describe the C172 brake system
Single disc brake, hydraulic pressure forces driected through a brake line which forces the brake pad to clamp around the steel disc. hydraulic fluid is orange/red in color
Why is the engine horizontally opposed?
What is air cooled?
What is Normally aspirated?
What is Direct Drive?
Why is the engine horizontally opposed? saves room, aerodynamic
What is air cooled? uses air to cool engine
What is Naturally aspirated? uses ambiant air for combustion
What is Direct Drive? crankshaft directly connected to the propeller
Fuel injected vs Carburetor?
Fuel Injected = distributes fuel more precisely to each cylinders, improving fuel economy & performace. Fuel vaporization takes place in the hot intake valves of the cylinder, minimizing potential icing
Carburetor = known to have a cylinder that is too lean or too rich, reducing fuel economy & performance. Vaporizes fuel at the throttle body, subjecting engine to icing.
What is the air induction?
takes outside air through a filter before going through the vacuum system and fuel air control unit. If the filter becomes clogged, and alternate air door on the left side will open by engine suction delivering unfiltered air to the engine, decreasing power by 10%
What does the alternate air door look like?
