Aircraft Systems Flashcards
Oil System Purpose (5)
Lubrication Cooling Cleaning Sealing Actuating
Components of Oil System (6)
When does the gauge begin to indicate for summer and winter?
Pump – circulates oil through system Sump – reservoir for oil Filter – removes contaminates from oil Oil Pressure Gauge –Should begin to indicate within… •30 seconds in summer •60 seconds in winter •Oil Temperature Gauge •Oil Cooler
Induction System Malfunctions (7)
Does the C172 come equipped with an alternate air?
Loss of Fuel Enrich Mixture Boost Pump Fuel Selector Loss of Air Carburetor Heat Alternate Air •C172 is equipped with an automatic “alternate air”
Methods of Leaning (2)
Best Economy – leaning for Best Economy allows the aircraft to remain aloft for a longer period of time
–Throttle: Adjust throttle to desired setting
–Mixture: Lean to peak Exhaust Gas Temperature (EGT)
Best Power – leaning for Best Power maximizes the aircrafts speed potential
–Throttle: Adjust throttle to desired setting
–Mixture: Lean to 50 F rich of peak EGT
–This is the recommended procedure by the Cessna PIM
Leaning
What does it do?
When do you lean?
Why do you lean?
Controlling the amount of fuel entering the carburetor for altitude or air density changes.
•When to Lean
–When operating at higher altitude (3,000 msl and above)
–At altitude, anytime there is a change in power setting
•Why Lean
–Air : Fuel Ratio must be correct (better performance)
When to Enrich Mixture (5)
–Full Throttle Operations –Descent –Close proximity to the ground –Traffic pattern operations –Engine Cooling
Fuel Injection System
What does it do?
What are the advantages? (5)
What are the disadvantages? (2)
Injector Nozzles spray fuel directly into intake manifold at cylinders
•Advantages –Better Cold Starts –Improved Performance –More efficient fuel distribution –Vaporization Ice problem removed
•Disadvantages
–Vapor Lock – difficulty starting engine when hot
–Plugged Injectors due to contamination
Oil Distribution - Wet Sump
What kind of aircraft is it for?
Name a specific aircraft that uses Wet Sump
How is it fed?
- Mostly for non-aerobatic aircraft
- C172S
- Gravity Fed
Oil Distribution - Dry Sump
What kind of aircraft is it for?
•Common among aerobatic aircraft
Oil System - Preflight
Oil Type (3)
Oil Quantity?
Oil Type
–Mineral – Used with a new engine
–Ashless Dispersant
–Synthetic
•Oil Quantity
–5-8qt
Cooling System
What are the effects of High Temperature Ops? (3)
Effects of High Temperature Operations
–Power Loss
–Excessive Oil Consumption
–Engine Damage
Types of Cooling Systems (2)
Additional Cooling Methods (3)
- Air (C172)
- Liquid
Additional Cooling Methods
–Increase Airspeed
–Enrich Mixture
–Decrease Power
Propeller
What’s it’s purpose?
What types are there? (3)
What type does the C172 have?
Purpose – converts engine torque into forward thrust
•Types
–Fixed Pitch – C172
–Controllable – blade angle can be changed in flight
–Constant Speed – blade angle changes automatically based on speed (RPM) set by pilot
Propeller Governor
What does it do?
What are it’s two functions.
Applies to constant speed propeller system
–Senses when the propeller is either too fast or too slow
–Uses engine oil to regulate the blade angle to maintain a desired speed (RPM)
•Changes blade pitch
Propeller Design Features (2) and what do they provide?
Pitch Angle of Blade
–For more power or more efficiency
•Blade Twist
–Compensates for the fact that the outward part of the blade travels a greater distance through the air than the hob of the blade does.
–Equal Thrust
Propeller - Pre-Flight (4)
Should you rotate prop by hand?
•Nicks •Secured to Crankshaft •Oil Leaks •Check Operation –Should you rotate by hand? NO
Propeller - Good Operating Practices (3)
Avoid operating above the red line
–2700 RPM
•Follow manufacturer’s recommendations
•Consider operating surface
–FOD
–Grass
–Ice
Fuel System - Types (2)
Gravity Type – gravity pulls fuel from the tanks down into engine
–Typical of high wing aircraft
•Pump – fuel is pumped from tanks to engine
Fuel System - Components (6)
•Tanks
•Pumps (2 total in C172)
–Engine Driven
–Electric Powered (auxiliary)
- Drains
- Vent
- Primer
•Gauges
–Fuel Quantity
–Fuel Pressure/Flow
C172 Fuel System
Total Capacity?
Unusable fuel?
Usable fuel?
What types of fuel pump are there?
Total capacity: 56 gallons
- Unusable fuel: 3 gallons
- Usable fuel: 53 gallons
•2 fuel pumps
–Electric
–Engine driven
Fuel System - Types of Fuel (4)
Alternate fuels?
AVGAS 80 - RED
AVGAS 100 - GREEN
AVGAS 100LL - BLUE
JET A - Colorless or Straw
Alternate Fuels
–Substitutions
•May use higher grade, NEVER LOWER!
Abnormality: Pre-Ignition
Definition?
Causes?
Signs of pre-ignition?
Solution?
•Ignition caused in advance of normal power stroke
•Usually resulting from hot spots in cylinder, caused by…
–Glowing deposits of lead (hot spots)
–Overheated spark plugs
–High power settings with excessively lean mixture
–More common in rear cylinders, due to reduced cooling
•Signs of Pre-Ignition
–Rough Running Engine
–Backfiring
–Rise in engine temperatures
•Solution – Reduce Engine Temperature
Abnormality Detonation:
•Occurs when the fuel/air mixture explodes in cylinder
–The fuel/air mixture should burn, not explode
–Typically occurs in all cylinders
•Characterized by:
–Excessive engine operating temperature
–Excessive Cylinder Head Temperature (CHT)
Fuel System - Good Practices (7)
- Check all fuel drains during preflight
- Keep tanks full during storage
- Use Higher Octane fuel if necessary, NEVER LOWER
- Electrically ground airplane during refueling
- Keep fuel vents clear of debris
- Visually check tanks for amount of fuel
- After fueling, wait 5 minutes before sumping
Fuel System - C172 POH Notes
When can you operate left or right tank.
Takeoff and landing settings?
Low fuel (1/4 or less) restriction
•Cessna 172
–Operation on either LEFT or RIGHT tank limited to level flight only
–Takeoff and land with the fuel selector valve handle in the BOTH position
–With ¼ tank or less, prolonged uncoordinated flight is prohibited when operating on either left or right tank
Fuel Emergencies (5)
- Check Fuel Selector
- Check Boost Pump
- Check Mixture
- Check Primer
- Check Fuel Gauges/Fuel Flow/Pressure
Hydraulic System - Components (7)
•Components of typical Hydraulic System -
–Fluid - MIL-H-5606
–Reservoir: source of fluid
–Pump: moves fluid
–Actuator: changes fluid pressure into mechanical action
–Valves: control fluid flow
–Lines: transfer fluid
Hydraulic System Examples (4)
- Wheel Brakes
- Retractable Landing Gear
- Constant Speed Propellers
- Flight Control Surfaces (Flaps, Ailerons, Spoilers)