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Aircraft Systems - QT

Updated: Apr 20, 2021

Lesson Quicktakes cover the items that should be memorized from each of the wifiCFI Lessons. They do not cover all of the lesson details in-depth.


RECIPROCATING ENGINES

Back and forth motion of the pistons.


SPARK IGNITION

Spark provided by Spark Plugs.


COMPRESSION IGNITION

Spark provided by Compression.


CYLINDER ARRANGEMENTS:

Radial Engine = Cylinders in Radial Formation.

  • High Power to Weight Ratio.


In-Line Engine = Cylinders in Straight Line Formation.

  • Small frontal area.

  • Lower Power to Weight Ratio.

  • Less Cooling for Rear Cylinders.


V-Type Engine = Cylinders in V Formation.

  • More horsepower than In-Line.

  • Small frontal area.


Opposed Engine = Cylinder Oppose each other.

  • Most popular in aviation.

  • Lightweight and compact.


4 STROKE CYCLE

  1. Intake Stroke = Suck.

  2. Compression Stroke = Squeeze.

  3. Power Stroke = Bang.

  4. Exhaust Stroke = Blow.

PROPELLER TWIST

Created for uniform thrust along the entire length of the blades.


PROPELLER TYPES:

Fixed Pitch = Blade Angles are set and do not vary.

  • Climb Prop = Good at Climbing. Not at Cruising.

  • Cruise Prop = Good at Cruising. Not at Climbing.


Adjustable Pitch = Blade Angles can be varied on the ground with engine not running.


Constant Speed Prop = Blade Angles vary in flight to maintain constant RPM.

  • High Blade Pitch = Lower RPM (more drag).

  • Low Blade Pitch = Higher RPM (less drag).


ENGINE INDUCTION:

Carburetor System = Mixes Fuel and Air in Carburetor before being sent to Cylinders.

  • Slower throttle response.

  • Subject to Carburetor Icing.


Fuel Injection = Mixes Fuel and Air just prior to entering Cylinders.

  • Better fuel flow.

  • Faster throttle response.

  • Precise mixture control.

  • Better fuel distribution.

  • Vapor lock can cause difficult hot weather starts.


OIL SYSTEMS:

  • Wet Sump System = Oil is located in a sump that is integral with engine.

  • Dry Sump System = Oil is contained in a separate tank that is not integral with engine.


COWL FLAPS:

  • Open = Releases hot air from engine cowling and cools engine.

  • Closed = Traps hot air in engine cowling and heats engine.


COMBUSTION ISSUES:

Detonation = Uncontrolled/explosive ignition of fuel-air-mixture (not a smooth burn).


Pre-Ignition = Fuel-air-mixture detonates too early.


FUEL SYSTEMS:

  • Gravity Feed Systems = Gravity moves fuel from tanks to engine (high wing aircraft).

  • Fuel Pump Systems = Fuel is transferred to fuel tanks via fuel pumps (low wing aircraft).


FUEL GRADES:


GENERATORS VS ALTERNATORS

  • Generators = Produce DC power. May not produce enough power at low RPM settings.

  • Alternators = Produce AC power. Can output enough power through a large range of RPM settings.


FUSES VS CIRCUIT BREAKERS

Protect the electrical system from overload and overheating.

  • Fuses = When blown, must be replaced.

  • Circuit Breakers = When popped, may be reset.


AMMETER VS LOADMETER

  • Ammeters = Shows if the alternator/generator is producing an adequate supply of electrical power. Negative indications mean there is not enough power and system may be drawing off battery.

  • Loadmeter = Shows the load being placed on the alternator/generator.


HYDRAULIC SYSTEM:

Often used to operate wheel brakes and retractable landing gear.


LANDING GEAR TYPES:

Tricycle Type:

  • Better braking at higher speeds.

  • Better forward visibility.

  • Prevents ground looping.


Tailwheel Type:

  • Keeps prop higher off the ground (off airport operations).

  • More susceptible to ground looping.


ANTI-ICE AND DE-ICE SYSTEMS:

  • De-Ice Boots = Inflatable boots on leading edge of wing to break ice.

  • Heated Wing = Wing is heated to melt ice. Typically from engine bleed air.

  • Weeping Wing = Leaks TKS fluid over wing to prevent ice build up.

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