amte218

• What is the course code for the Aircraft Instrument and Engine Instrument class?

  AMTE 218
• Why must maintenance technicians be familiar with various types of instruments?

  To convey information to the pilot
• What do flight instruments depict?

  The attitude, airspeed, and altitude of the aircraft
• What type of information do other instruments provide besides flight instruments?

  Engine operational parameters and electrical system performance
• What are technicians prohibited from doing regarding aircraft instruments?

  Performing any maintenance or repairs to the actual instruments
• What must technicians maintain that supports the instruments?

  Electrical wiring and fluid-line plumbing
• What contributed to the growth of the present air transportation system?

  The development of efficient flight instruments
• What was the state of airplane navigation before World War II?

  Few airplanes were equipped for flight without using ground reference navigation or pilotage
• What was the consequence of poor visibility or low cloud cover before instrument flight?

  It required flying at dangerously low altitudes or not flying at all
• Who made a flight without outside visual references on September 24, 1929?

  Jimmy Doolittle
• What instruments did Jimmy Doolittle use during his flight?

  An artificial horizon, a sensitive altimeter, and a radio direction finder
• What did Doolittle's flight prove?


  That blind flight was indeed possible
• When did instrument flight in zero visibility become commonplace in civilian aviation?

  During the 1940s
• What did the newly developed flight instruments allow pilots to do?

  Keep the airplane straight and level with no outside reference
• How do flight instruments and navigation equipment typically operate?

  In conjunction with each other, particularly with modern auto-flight systems
• What has revolutionized flight instrumentation and control systems?

  Integrated circuits containing microprocessors and other digital electronics
• What do many aircraft instruments rely on for measurement?

  Measuring the pressures of fluids such as air, fuel, and oil
• How can pressures be measured in aircraft instruments?

  By applying the fluid's force to a movable bellows or using a transducer
• What is pressure defined as?

  The force differential between two points
• What is atmospheric pressure created by?

  The weight of all the air that sits on top of the earth's surface
• Why is it necessary to establish an average or "standard day" pressure value?

  Because many factors cause atmospheric pressure to vary
• What is the common reference for temperature and pressure called?

  The International Standard Atmosphere (ISA)
• How can atmospheric pressure be measured?

  With a mercury barometer
• How does a mercury barometer work?

  The weight of the atmosphere causes mercury to rise in an inverted tube
• What height of mercury column does standard atmospheric pressure support at sea level?

  29.92 inches
• Why is standard pressure important for aircraft and engine performance specifications?

  Because it can change with weather patterns affecting aircraft performance
• How does atmospheric pressure affect lift produced by a wing?

  As atmospheric pressure changes, the amount of lift produced by the wings changes
• Why is it important for an aircraft technician to understand pressure changes?

  Because pressure changes directly affect the performance characteristics of an aircraft
• What are the three basic ways of measuring pressure?

  • Absolute pressure
  • Gauge pressure
  • Differential pressure
• What is absolute pressure?


  The measurement of pressure relative to a total vacuum
• How is atmospheric pressure measured in absolute terms?

  In inches of mercury, hectoPascals, or pounds per square inch (psi)
• What is the modern term for the older measurement called "millibars"?


  HectoPascals (hPa)
• What does 29.92 inches of mercury equal under standard day conditions?

  1013.2 hPa or 14.7 psi
• How is absolute pressure compared on aircraft?

  In comparison to other pressures using an aneroid wafer
• What is an aneroid wafer?

  A device that measures the difference in pressure between a vacuum and ambient pressure
• How does the aneroid wafer work?

  Expansion and contraction of the pressure capsule moves a needle on a gauge
• What is gauge pressure?

  The difference between atmospheric pressure and the pressure being measured
• How is gauge pressure measured?


  By applying a pressure to a given area and measuring the force it exerts
• What happens when a force of 32 psi is applied to one side of a bellows with 14.7 psi on the other side?

  The resulting force is 17.3 psi
• How can the force applied to a bellows be calculated?

  By multiplying the pressure by the surface area of the bellows