Aircraft Instrument Systems Flashcards
The fixed line attached to the compass bowl of a magnetic compass is called?
The lubber line
No.1 Aircraft instruments are color-coded to direct attention to operational ranges and limitations
Only No.1 is true
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?
Altimeter and airspeed indicator will indicate low
The max deviation (during level flight) permitted in a compensated magnetic direction indicator installed on an aircraft certified under part FAR 23 is
10 degrees
Magnetic compass bowls are filled with a liquid to
dampen the oscillation of the float
Instrument static system leakage can be detected by observing the rate of change in indication of the
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
100 feet in 1 min
Which of the following instrument discrepancies could be corrected by an aviation mechanic?
Red line missing, mounting screws loose, case paint chipped, leaking at line B nut
Which of the follow instrument conditions is acceptable and would not require correction?
Case paint chipped
A barometric altimeter indicates pressure altitude when the barometric scale is set at
29.92” Hg
A bourdon tube instrument may be used to indicate
pressure and temperature
A turn coordinator instrument indicates
both roll and yaw
Aircraft temperature thermocouple leads may
not be altered and are designed for a specific installation
A synchro transmitter is connected to a synchro receiver
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 temperature are measured by using
chrome/alumel thermocouples
Which of the following causes of aircraft magnetic compass inaccuracies may be compensated for by mechanics?
Deviation
Who is authorised 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
inspections and function check on aircraft instruments
What does a reciprocating engine manifold pressure gauge indicate when the engine is not operating?
The existing atmospheric pressure
The requirements for testing and inspection of instruments static systems required by (FAR) 14 CFR Section 91.411 are contained in
(FAR) 14 CFR 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
digital signals
The function of a CRT (Cathode Ray Tube) in an EFIS is to
display alphanumeric data and representations of aircraft instruments
The function of a symbol generator (SG) in an EFIS is to
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
allow the pilot to select the appropriate system configuration for the current flight situation
A radar altimeter determines altitude by
transmitting a signal and receiving back a reflected signal
A radar altimeter indicates
altitude above ground level
Resistance-type temperature 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 temp
When flags such as NAV, HDG or GS are displayed on an HSI, the indication is
that function is INOP
Instrument panel shock mounts absorb
low frequency, high-amplitude shocks
What determines the number of shock mounts that need to be installed on an instrument panel?
Weight of the complete panel
Which procedure should you use if you find a if you find a vacuum-operated instrument panel glass loose?
Install another instrument
Which of the following instruments will normally have range markings?
Cylinder head temp 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
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 the cover glass has slipped?
White
Aircraft instrument should be marked and graduated in accordance with
the specific aircraft maintenance or flight manual
Aircraft instrument panels are generally shock mounted to absorb
low frequency, high amplitude shocks
The method of mounting aircraft instruments in their respective panels depends on the
design on 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 if the instrument panel
Cases for electrically operated instruments are made of
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 instruments?
Aircraft flight manual or aircraft maintenance manual
A certificated mechanic with airframe and powerplant ratings may
not perform repair to aircraft instruments
The red radial lines on the face of an engine oil pressure gauge indicates
minimum and/or maximum safe operating limits
A certificated mechanic may perform
100-hour inspections of instruments
An aircraft instrument panel is electrically bonded to the aircraft structure to
provide current return paths
How many of the following are controlled by gyroscopes?
1. Altitude indicator
2. Heading indicator
3. Turn needle of the turn and slip indicator
Three
The lubber line on a directional gyro is used to
represent the nose of the aircraft
Which instruments are connected to an aircrafts static pressure system only?
Vertical speed indicator and altimeter
When an unpressurized aircraft static pressure system is leak checked to comply with the requirements of (FAR) 14 CFR Section 91.411, what aircraft instrument may be used in lieu of pitot-static system tester
Altimeter
If a static pressure system check reveals excessive leakage, the leak(s) may be located by
isolating portions of the line and testing each portion systemically, starting at the instrument connections
When performing the static system leakage check required by (FAR) 14 CFR Section 91.411, the technician utltizes
negative pressure
What is the primary purpose of an autopilot?
To relieve the pilot of control of the aircraft during long periods of flight
Which of the following provides manual maneuverability of the aircraft while the autopilot is engaged?
Flight controller
In an autopilot, which signal nullifies the input signal to the ailerons?
Follow up signal
In which control element of an autopilot system is an altitude indicator?
Sensing
What is the operating principle of the sensing device used in an autopilot system?
The relative motion between a gyro and its supporting system
What will occur if an aircraft altitude is changed by its autopilot system in order to correct for an error and the involved control surfaces are returned to streamline by the time aircraft has reached its correct position?
Normal operation
What component of an autopilot system applies torque to the control surfaces of an aircraft?
Servo
What is the main purpose of a servo in autopilot system?
Move the control surface as commanded
Which channel of an autopilot detects changes in pitch attitude of an aircraft?
Elevator
The elevator channel of an autopilot controls the aircraft about which axis of rotation?
Lateral
What component is the sensing device in an electromechanical autopilot system?
Gyro
A fully integrated autopilot controls the aircraft around how many axis?
Three
Dutch roll, a combination of yawing and rolling oscillation that affects many swept wing aircraft, is counteracted with
yaw damper system
When operationally checking an autopilot system on the ground, after the aircraft’s main power has been switched on, the autopilot should be engaged
only after the gyros comes up to speed and the amplifier warms up
