Operation of Systems


Understand the purpose and operation of fixed wing, non-complex, single-engine piston airplane systems, including the flight controls, powerplant, basic electrical components, and flight instruments.


This is the required reading for this lesson. Numbers in [brackets] indicate the starting and ending page in the referenced reading material. Read all the pages and sections referenced.

  • Pilot's Handbook of Aeronautical Knowledge
    • Chapter 6 - Flight Controls
      • [6-1 to 6-6] "Flight Controls" to "Elevator"
      • [6-8] "Rudder"
      • [6-8 to 6-9] "Secondary Flight Controls" to "Flaps"
      • [6-12] "Autopilot" to "Chapter Summary"
    • Chapter 7 - Aircraft Systems
      • [7-1 to 7-6] "Powerplant" to "Fixed-Pitch Propeller"
      • [7-7 to 7-12] "Induction Systems" to "Fuel Injection Systems"
      • [7-15 to 7-20] "Ignition Systems" to "Combustion"
      • [7-25 to 7-26] "Airframe Systems" to "Fuel Selectors"
      • [7-30 to 7-34] "Electrical Systems" to "Brakes"
      • [7-37 to 7-41] "Oxygen Systems" to "Anti-Ice and Deice Systems"
    • Chapter 8 - Flight Instruments
      • [8-1 to 8-20] "Introduction" to "Attitude and Heading Reference System (AHRS)"
      • [8-23 to 8-27] "Compass Systems"


The notes below highlight the important parts in the referenced material. Reading the notes without having read the actual referenced material is generally not sufficient to pass the written exam!

PHAK - Chapter 6

  • The flight controls control the forces of flight and the aircraft's direction and attitude.
  • Primary flight controls are
    • Ailerons
    • Elevator
    • Rudder
  • Secondary flight controls found on most small aircraft are
    • Wing flaps
    • Trim
  • Ailerons control roll. Elevator controls pitch. Rudder controls yaw.
  • Wing flaps increase lift and drag. Trim reduces control pressure.
  • Adverse yaw is produced whenever the ailerons are moved.
  • Aileron and rudder must be moved together for a coordinated turn.

PHAK - Chapter 7

  • Two key aircraft systems are
    • Powerplant
    • Electrical systems
  • The powerplant (engine) is the heart of the aircraft, and converts fuel to energy in order to provide:
    1. thrust to propel the aircraft via the propeller,
    2. power for the electrical system via the alternator,
    3. hydraulic pressure for systems (such as brakes),
    4. vacuum pressure for instruments,
    5. heat for the cabin.
  • Several subsystems assist the powerplant:
    • induction (fuel-air mixing),
    • ignition (fuel combustion),
    • fuel (storage and delivery),
    • lubrication (oil), and
    • cooling (oil, cowling, exhaust).
  • The electrical system's core components are the battery and alternator, which provide power to the:
    • engine starter & electric fuel pump
    • pitot heat & stall warning system
    • instruments (fuel gauges, turn indicator)
    • lights
  • Four-stroke engine:
    1. Intake
    2. Compression
    3. Power
    4. Exhaust
  • Carburetor vs. Fuel Injection systems
    • Carburetor vulnerable to icing; requires use of carburetor heat.
    • Fuel Injection vulnerable to vapor lock; difficulty starting hot engine.
  • The magnetos power the spark plugs separately from the electrical system.
  • The mixture controls the fuel-air mixture.
    • Less fuel is required at high altitude due to less air density
    • More fuel is required at low altitude due to high air density.
  • An improper mixture will result in less power..

PHAK - Chapter 8

  • Flight instruments may be displayed as
    • "steam gauges"
    • "glass panel"
  • Flight instruments are classified as one of two types:
    • pitot-static
    • gyroscopic
  • The pitot-static instruments include the airspeed indicator, vertical speed indicator (VSI) and altimeter.
    • Sources and possible failures:



      If source is blocked...

      Airspeed Indicator Pitot-tube Complete Blockage: Faster above, slower below
      Partial Blockage: 0 indication
      Static port Indicates slower above, faster below
      VSI Static port 0 indication
      Altimeter Static port Frozen altitude
    • Altimeter is also affected by inaccurate atmospheric pressure settings.
  • The gyroscopic instruments include the: turn coordinator, heading indicator, and attitude indicator.
    • Gyroscopic instruments rely on the engine-driven vacuum pump or the electrical system:
      • Turn coordinator: electrical system
      • Heading indicator: vacuum pump
      • Attitude indicator: vacuum pump
    • Gyroscopic instruments may become unreliable due to...
      • Precession/Drift. The heading indicator must be periodically corrected to match the compass while in straight and level, unaccelerated flight.
      • Low vacuum pressure. The heading and attitude indicator will be inaccurate. (Note that many aircraft have engine-driven vacuum pumps; an engine failure will result in loss of vacuum pressure.)
      • Electrical failure. The turn coordinator will not function.

Sim Pilot Notes

These notes highlight the differences between simulator and real-world flying. These differences are most often due to simulator limitations or specific VATSIM rules.

Chapter 7

  • Oxygen: Most default aircraft do not simulate oxygen systems. However, some add-on aircraft will simulate these systems, including blacking out due to lack of oxygen at high altitudes! Become familiar with your virtual airplane to ensure you don't end up watching your screen slowly fade to black!

Chapter 8

  • Altimeter settings: Real-world and in the sim, the altimeter setting is usually received via the ATIS weather broadcast at the airport or ATC will often provide the current altimeter setting to you as a courtesy. However, be careful in the sim! Depending on your sim's weather source, the correct altimeter setting for you might be different from what is provided by the ATIS or ATC. In order to appear at the correct altitude to other pilots and ATC on the network, you should set the altimeter setting to match your sim's weather. If on the ground, and the current pressure setting is unavailable, you can also set your altimeter to the field elevation as an alternative.

Tomas Hansson (This email address is being protected from spambots. You need JavaScript enabled to view it.)
Chief Flight Instructor, VATSTAR
DISCLAIMER: all information contained herein is for flight simulation purposes only.
March 2021

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