Aircraft Instrument Systems Flashcards
An aircraft magnetic compass is swung to update the compass correction card when what?
equipment is added that could effect compass deviation.
Which of the following operating mechanisms would be found in a hydraulic pressure gauge?
Bourdon tube.
What is the fixed line mark attached to the compass bowl of a magnetic compass called?
Lubber line.
Which of the following will cause inaccuracies in a magnetic compass that may be compensated for by an aircraft mechanic?
Deviation.
What will be the result if the instrument static pressure line becomes disconnected inside a pressurized cabin during cruising flight?
The altimeter and airspeed indicator will both read low.
The maximum deviation (during level flight) permitted in a compensated magnetic direction indicator installed on an aircraft certificated under 14 CFR Part 23 is what?
10 Degrees.
Magnetic compass bowls are filled with a liquid to what?
Dampen the oscillation of the float.
Instrument static system leakage can be detected by observing the rate of change in indication of the what?
altimeter after suction has been applied to the static system to cause a prescribed equivalent altitude to be indicated.
The maximum altitude loss permitted during an unpressurized aircraft instrument static pressure system integrity check is what?
100 feet in 1 minute.
Which statement regarding an aircraft instrument vacuum system is true?
Dry-type vacuum pumps with carbon vanes are very susceptible to damage from solid airborne particles and must take in only filtered air.
When an aircraft altimeter is set at 29.92 “Hg on the ground, the altimeter will read what?
pressure altitude.
Which of the following instrument discrepancies would require replacement of the instrument?
Case leaking, glass cracked, instrument will not zero out, or fogged.
Which instrument condition is acceptable and would not require correction?
Case paint chipped.
A barometric altimeter indicates pressure altitude when the barometric scale is set at what?
29.92 “Hg.
At sea level, when the average atmospheric pressure is 14.7 psi, the barometric pressure is what?
29.92 “Hg.
A Bourdon tube instrument may be used to indicate what?
Pressure and temperature.
A turn coordinator instrument indicates what?
Both roll and yaw.
Aircraft temperature thermocouple leads may what?
Not be altered and are designed for a specific installation.
A synchro transmitter is connected to a synchro reciever how?
Electrically with wires.
The operation of an angle of attack indicating system is based on detection of differential pressure at a point where the airstream flows in a direction…
not parallel to the true angle of attack of the aircraft.
Turbine engine exhaust gas temperatures are measured by using what?
chromel/alumel thermocouples.
Fuel flow transmitters are designed to transmit data how?
electrically.
Which of the following causes of aircraft magnetic compass inaccuracies may be compensated for by mechanics?
Deviation.
Who is authorized to repair an aircraft instrument?
A certificated repair station approved for that class instrument.
A certificated mechanic with at least an airframe rating may perform what?
Inspections and function checks on aircraft instruments.
What does a reciprocating engine manifold pressure gauge indicate when the engine is not operating?
The existing atmosphere pressure.
The requirements for testing and inspection of instrument static pressure systems required by 14 CFR 91.411 are contained in what?
Part 43, appendix E.
Which condition would be most likely to cause excessive vacuum in a vacuum system?
Vacuum relief valve improperly adjusted.
Data transmitted between components in an EFIS are converted into what?
Digital signals.
The function of a CRT in an EFIS is to what?
Display alphanumeric data and representations of aircraft instruments.
The function of a symbol generator (SG) in an EFIS is to what?
Receive and process input signals from aircraft and engine sensors and send the data to the appropriate display.
The function of a display controller in an EFIS is to what?
Allow the pilot to select the appropriate system configuration for the current flight situation.
A radar altimeter determines altitude by what?
transmitting a signal and receiving back a reflected signal.
A radar altimeter indicates what?
altitude above ground level.
Resistance-type temperature indicators using Wheatstone bridge or ratiometer circuits may be used to indicate the temperatures of which of the following?
Free air, carburetor air, coolant (engine), and oil temperature.
When flags such as NAV, HDG, or GS are displayed on an HSI, the indication is what?
that function is inoperative.
Instrument panel shock mounts absorb what?
low-frequency, high-amplitude shocks.
Which procedure should you use if you find a vacuum-operated instrument glass loose?
Install another instrument.
Which instrument are connected to an aircraft’s pitot-static system?
Vertical speed indicator, altimeter, and airspeed indicator.
Which of the following instruments will normally have range markings?
Cylinder head temperature gauge and airspeed indicator.
How would an airspeed indicator be marked to show the best rate-of-climb speed (one engine inoperative)?
A blue radial line.
The green arc on an aircraft temperature gauge indicates what?
The desirable temperature range.
What must be done to an instrument panel that is supported by shock mounts?
Bonding straps must be installed across the instrument mounts as a current path.
What marking color is used to indicate if a cover glass has slipped?
White.
Aircraft instruments should be marked and graduated in accordance with what?
The specific aircraft maintenance or flight manual.
Aircraft instrument panels are generally shock-mounted to absorb what?
Low-frequency, high-amplitude shocks.
The method of mounting aircraft instruments in their respective panels depends on the what?
Design of the instrument case.
How is a flangeless instrument case mounted in an instrument panel?
By an expanding-type clamp secured to the back of the panel and tightened by a screw from the front of the instrument panel.
Cases for electrically operated instruments are made of what?
Iron or steel cases.
When installing an instrument in an aircraft, who is responsible for making sure it is properly marked?
The mechanic installing the instrument.
Where may a person look for the information necessary to determine the required markings on an engine instrument?
Aircraft flight manual or aircraft maintenance manual.
A certificated mechanic with airframe and powerplant ratings may what?
not perform repairs to aircraft instruments.
The red radial lines on the face of an engine oil pressure gauge indicates what?
minimum and/or maximum safe operating limits.
A certificated mechanic may perform what?
100-hour inspections of instruments.
An aircraft instrument panel is electrically bonded to the aircraft structure to what?
Provide current return paths.
How many of the following are controlled by gyroscopes?
Three.
Attitude indicator
Heading indicator
Turn needle of the turn-and-slip indicator
The lubber line on a directional gyro is used to what?
Represent the nose of the aircraft.
Which instruments are connected to an aircraft’s static pressure system only?
Vertical speed indicator and altimeter.
When an unpressurized aircraft’s static pressure system is leak checked to comply with the requirements of 14 CFR 91.411, what aircraft instrument may be used in lieu of a pitot-static system tester?
Altimeter.
If a static pressure system check reveals excessive leakage, the leak(s) may be located by what?
Isolating portions of the line and testing each portion systematically starting at the instrument connections.
When performing the static system leakage check required by 14 CFR 91.411, the technician utilizes what?
Negative pressure.
Which of the following aircraft instrument discrepancies could be corrected by an aviation mechanic?
Red line missing, mounting screws loose, case paint chipped, or leaking at line B nut.
