Chapter 11 - Aircraft Instrument Systems - Oral Questions Flashcards
A static check may be performed on a manifold pressure gauge by using what piece of information?
Current atmospheric pressure
What aircraft instrument can be used to check a manifold pressure gauge for proper indication?
Altimeter
Name several of the indication errors that may be found in altimeters
Scale errors, hysteresis, friction, installation
Scale Error - The altimeter must indicate the same altitude shown on the master indicator or manometer within a specified allowable tolerance
Hysteresis - The reading taken with the altitude increasing must agree with the readings at the same pressure level when the altitude is decreasing. A specified tolerance is allowed for this test.
Friction - Two altitude readings are to be taken at each pressure level, one before and one after the instrument is vibrated. There should be no more than a specified difference between the two readings.
Case leak - When the pressure inside the altimeter case corresponds to an altitude of 18,000 feet, is should not leak down more than a specified amount in a specified period.
What is the signal source in an electrical resistance type temperature indicating system?
A temperature bulb or sensing element
What type of temperature sensing system is normally used to measure a turbine engine exhaust gas temperature?
A thermocouple type system
What operating parameter is indicated by a tachometer?
Engine RPM (crankshaft or turbine rotor speed)
What is the name of the effect that causes a gyro to respond to an applied force at a point 90 degrees further in the direction of rotation?
Gyroscopic precession
What aircraft instruments are connected to the pitot-static system?
The altimeter,
vertical speed indicator,
airspeed, and
mach meter in high performance jets
What are the three sources of power used to drive a gyroscopic turn indicator?
Air from a vacuum source, from a pressure source, or an electric motor
What are two items that should be considered during inspection of a magnetic compass?
- The fluid must be clear
- The housing must be full with no bubbles
- The card must be legible and the lubber line intact
- The compass should be properly calibrated
In what way do magnetic fields generated by electrical equipment and steel parts in the airplane affect a magnetic compass?
Stray magnetic fields deflect the compass from the correct alignment with the earth’s magnetic field
Describe the basic operating concept of a synchro-type remote indicating system
A remote transmitter electrically signals a receiver inside the instrument
Why should you avoid cleaning obstructions from the sensing holes in a pitot-static system with a tool?
The holes are aerodynamically critical
(there needed for the instruments to work properly)
After components in a pitot-static system have been replaced, what tests or inspections are required?
The static system leak test specified in FAR 91.411
What quantity is measured by a capacitance type fuel quantity indicating system?
Mass of the fuel
What is the meaning of a yellow arc on an aircraft instrument?
A caution or limited flight operations range
