Ground lesson 2 - Airplane systems & flight inst

• Airplane
• Fuselage
• Houses the cabin/cockpit
• Semi Monocoque structure
• Strong but can't tolerate dents
  
  
  

• Wings
• When air flows around the wings, it generates lift
• Attached to the wings you have ailerons and flaps

• Ailerons
• Move in opposite directions to allow the aircraft to turn

• Flaps
• Move simultaneously to increase the lift force for takeoff, landings, and maneuvers.

• Empennage
• Typically consists of vertical stabilizer, rudder, horizontal stabilizer, and the elevator
• They help steady the aircraft
• The rudder can be used to move the nose left and right
• The elevator can be used to move the nose up and down

• Landing gear
• Absorbs landing loads and supports the airplane on the ground
• Attached to the strut which absorbs impacts

• Engine/propeller
• Primary function of the engine is to provide power to the propeller
• The propeller translates the rotating force of the engine into a forward acting force called thrust.

• POH
• Most of the pertinent info about a particular make and model of airplane can be found in the POH
  
  
  

• Powerplant and related systems
• Reciprocating engines (piston)
• Four stroke cycle
• Intake (fuel/ air)
• Compression
• Ignition
• Exhaust
  
  

• Cessna 152 engine
• Engine Manufacturer
• Avco Lycoming.

• Engine Model Number
• O-235-L2C.

• Engine Type
• Normally-aspirated - air intake depends solely on atmospheric pressure
• Direct-drive - power straight from the engine crankshaft to the prop
• Air-cooled
• Horizontally opposed
• Carburetor equipped
• Four-cylinder engine with 233.3 cu. in displacement.

• Horsepower Rating and Engine Speed: HO rated BHP at 2550 RPM.

• Induction system
• Air filter
• Intake air is filtered to prevent the intake from dust and other foreign objects
• Located below the carburetor

• Carburetor
• Air is mixed with vaporized fuel as it passes through a venturi
• The metered fuel/air mixture is then delivered to the cylinder intake

• Carburetor ICE
• Causes
• Fuel vaporization and decreasing air pressure in the venturi causes a drop in temp.
• If the air is moist, the water vapor in the air may condense
• In low power settings, the butterfly valve creates a second venturi, ice is built there
• Low temperatures ( see POH)

• Indications
• Decrease in engine RPM
• Engine roughness

• Prevention
• Carb. heat should be used in low r.p.m settings or when ice is suspected

• Ignition system
• Provides the spark that ignites the fuel air mixture in the cylinder
• 2 magnetos → 2 reasons
• Redundancy
• Efficiency
• Two magnetos are connected in such a way that one drives the top spark plugs and the other the bottom plugs.
• The magnetos generate power independently of the aircraft electrical system, so that in the event of flat battery during flight the engine will keep running. 

• 2 spark plugs in each cylinder
• Two spark plugs and separate ignition circuits are used per cylinder for redundancy, safety and better ignition and combustion of the mixture

• Fuel system
• Consists of
• Fuel tanks
• Fuel quantity gauge
• Shut-off valve
• Fuel filter
• Fuel line to the engine
• Possibly a primer and fuel pumps

• Fuel travels from the fuel tank through a shut-off valve, which provides a means to completely stop fuel flow to the engine in the event of an emergency or fire
• Primer allows fuel to be pumped directly into the intake port of the cylinders prior to engine start

• Gravity flow fuel system
• Fuel grade
• Av gas - 100LL - light blue

• Fuel tanks
• 26G total

• 24.5 G usable
• Usable fuel
• Guaranteed to get to your engine anywhere inside your normal operating limits
• 30 degrees nose up and nose down, 60 degree banks.

• Unusable fuel
• Not guaranteed to make it to your engine in those conditions.
• The fuel pickup is not at the absolute bottom of the tank. Some space is left in case there is some water or sediment.

• Fuel shutoff valve → enables and disables fuel flow out of the tank

• Refueling
• Use a ground wire to reduce static electricity and possible spark between refueling equipment and aircraft.
• Make sure you are using the proper grade fuel. 

• Oil system
• Oil cleans and lubricates(cools) the engine
• Improves efficiency by provides seal between cylinder walls and piston
• Oil level
• Minimum - 4qt
• Maximum - 6qt

• Gauges
• Temperature gauges
• If oil temp. to low
• Not enough lubrication
• High oil pressure

• If oil temp to high
• Oil loses the capability of lubrication
• Low oil pressure

• Cooling system
• The combustion process that takes place in the engine produces intense heat
• Excessively high engine temp. can result in loss of power, high oil consumption, and engine damage.
• Outside air usually enters the engine compartment through an inlet behind the propeller hub
  
  
  
  

• Exhaust system
• Vent burned gas
• Provide cabin heat
• Defrosting the windscreen

• Propellers
• Provides thrust
• Speed varies along the propeller blade span
• Blade twist allows more uniform thrust throughout most of the length of the blade
• There are Fixed pitch propeller and constant speed propellers

• Propeller hazards
• Provide your passenger with a thorough briefing so they stay clear of the propeller

• Electrical system
• Battery
• 24V/ 25A
• Needed to start engine
• Provides backup power

• Alternator
• 28V/ 60A
• Driven by the engine
• Supplies electrical system with power
• Charges the battery
• Over-voltage relay → turn off the alternator when it is producing to much power

• Bus bar
• Alternator delivers direct current to the bus bar
• Bus bar distributes the current to various electrical components
• Ammeter
• Monitors the electrical current in amperes within the system

• Master switch
• Controls entire electrical system.
• Circuit breakers
• Used to protect various components from overload or short
• Circuit will continue to pop out, indicating an electrical problem

• ISA - International standard atmosphere
• Used by aviation
• Calibrate instruments
• Determine aircraft performance 

• ISA standard day
• Based on sea level
• Temp. is 15ºC
• Pressure is 29.92 inches of mercury 

• Standard lapse rate
• Temp. 2ºC per 1000 feet
• Pressure 1’’ per 1000 feet

• Flight instruments
• Pitot static system
• Pitot tube
• Dynamic pressure enters (ram air)
• Drain hole
• Some aircrafts have pitot heat
• Used by airspeed indicator

• Static port
• Measures static pressure
• Used by ASI, VSI, and ALT
  
  
  

• Airspeed indicator
• Function
• Indicates the speed of the aircraft through the air
• Compares dynamic pressure with static pressure
• The greater the difference, the greater the speed

• Different airspeeds
• Indicated airspeed
• Reading on the ASI
• Calibrated airspeed
• Airspeed corrected for installation and instrument error
  
   
• True airspeed
• Airspeed relative to surrounding air
• Ground speed
• Speed over ground
• Altimeter
• Function
• Measures the difference between static pressure and altimeter setting
• Static port connected to the housing
• Wafer has set pressure

• Different altitudes
• Indicated altitude
• Reading on the altimeter

• Absolute altitude
• Altitude above the ground

• True altitude
• Altitude above sea level

• Pressure altitude
• Altitude corrected for non standard pressure

• Density altitude
• Altitude corrected for nonstandard temperature 

• Vertical speed indicator
• Function
• Displays rate of climb/ descent
• Measures how fast the static pressure increases and decreases
• Static pressure enters diaphragm which instantly compresses/ decompresses
• Static pressure also enters VSI housing through calibrated leak
  
  
  
  

• ICING
• Pitot tube ice
• Only affects the airspeed indicator
• Pitot + drain clogged = ASI works as altimeter
• Higher altitude = higher airspeed

• Pitot tube ice, drain cleared
• Drain hole lets the pressure out, airspeed drops to zero

• Static port ice
• Affects ASI, ALT, VSI
• ASI
• Works normal at altitude it froze at
• Higher airspeed at lower altitude, lower airspeed at higher altitude 

• ALT
• Freezes at current altitude 

• VSI
• Shows zero, senses no difference in pressure

• Alternate static source
• Break the VSI glass
• ASI and ALT will show higher than normal
  
  
  

• Magnetic compass
• Function
• Self contained
• Aircraft rotates around the compass card

• Magnetic fields of the earth
• The earth is a huge magnet surrounded by a magnetic field made up of lines of flux
• These lines leave magnetic north pole and reenter the south pole 

• Variation
• Angle between magnetic north and true north
  
  
  
• Deviation
• Compass errors caused by magnetic disturbances from electrical and metal components in the aircraft
• Magnets installed in housing to compensate for the error
• Correction is placarded on the compass
  
  
  
  

• Oscillation
• Erratic movements of the compass card
• Turbulence , control inputs 

• Magnetic dip
• Tendency of the north seeking needle to deflect downward as it approaches the north pole
• Flux is Perpendicular at the magnetic north pole
• Strong deflection 

• Flux is parallel at the equator
• No dip error

• Dip compensating weight at the “south end
  
  
  
  

• Dip errors
• Acceleration / deceleration errors
• Because of the weight that compensates for magnetic dip
• Most noticeable on easterly or westerly headings
• None at north or south headings
• ANDS
• accelerate north/ decelerate south
  
  
  
  

• Turn errors
• Most noticeable when turning to/from a north or south heading, none at east/west
• UNOS
• Undershoot north, overshoot south
• When on a south heading and turning north, needle leads