DGCA Air Navigation: Pitot-Static System Questions

76 exam-style Pitot-Static System questions for the DGCA Air Navigationpaper (CPL & ATPL). The first 12 are free below with answers and explanations — sign up free to practise all of them with progress tracking.

  1. Q1

    Concerning the pitot static system, the static pressure error?

    • A. Is a direct effect of blockage of the static ports.
    • B. is a direct effect of heating of the static ports.
    • CAffects the alternate static source only.
    • D. Is caused by disturbed airflow around the static ports.
    Show answer

    Correct answer: D. . Is caused by disturbed airflow around the static ports.

    Static (position) pressure error is caused by disturbed airflow around the static ports.

  2. Q2

    The pressure measured at the forward facing orifice of a pitot tube is the :

    • Atotal pressure plus static pressure.
    • Bstatic pressure
    • Ctotal pressure
    • Ddynamic pressure
    Show answer

    Correct answer: C. total pressure

    This Explanation is Coming Soon

  3. Q3

    The alternate static source of a light non-pressurised aeroplane is located in the flight deck. When used the altimeter?

    • ATends to over read
    • BTens to under read
    • Cis blocked
    • DIndicates zero
    Show answer

    Correct answer: A. Tends to over read

    Cabin static is lower than ambient, so on the alternate static source the altimeter tends to over-read.

  4. Q4

    The alternate static source of a light non-pressurised aircraft is located in the flight deck. When it is used, the static pressure sensed is likely to be?

    • ALower than ambient pressure if QNH is greater than 1013 hPa
    • BLower than ambient pressure due to aerodynamic suction
    • CHigher than ambient pressure due to aerodynamic suction
    • DHigher than ambient pressure if QNH is greater than 1013 hPa
    Show answer

    Correct answer: B. Lower than ambient pressure due to aerodynamic suction

    Flight-deck cabin pressure is lower than ambient because of aerodynamic suction over the fuselage.

  5. Q5

    A pitot tube covered by ice which blocks the ram air inlet will affect the following instrument (s) :

    • Aairspeed indicator, altimeter and vertical speed indicator
    • Bvertical speed indicator only.
    • Caltimeter only
    • Dairspeed indicator only
    Show answer

    Correct answer: D. airspeed indicator only

    This Explanation is Coming Soon

  6. Q6

    The pressure altitude is the altitude corresponding?

    • AIn standard atmosphere, to the reference pressure Ps.
    • BIn ambient atmosphere, to the pressure Ps prevailing at this point.
    • CIn standard atmosphere, to the pressure Ps prevailing at this point.
    • DIn ambient atmosphere, to the reference pressure Ps.
    Show answer

    Correct answer: C. In standard atmosphere, to the pressure Ps prevailing at this point.

    Pressure altitude is the altitude in the standard atmosphere at which the prevailing pressure occurs.

  7. Q7

    In a non-pressurized aircraft, if one or several static pressure ports are damaged, there is an ultimate emergency means for restoring a practically correct static pressure intake :

    • Abreaking the rate-of-climb indicator glass window
    • Bcalculating the ambient static pressure, allowing for the altitude and QNH and adjusting the instruments
    • Cdescending as much as possible in order to fly at a pressure as close to 1013.25 hPa as possible
    • Dslightly opening a window to restore the ambient pressure in the cabin
    Show answer

    Correct answer: A. breaking the rate-of-climb indicator glass window

    This Explanation is Coming Soon

  8. Q8

    The ADC uses the following parameters as input data:

    • AMach number, barometric altitude, CAS.
    • BTAS, barometric altitude, TAT.
    • CStatic pressure, total pressure, TAT.
    • DTotal pressure, static pressure, TAT, EGT.
    Show answer

    Correct answer: C. Static pressure, total pressure, TAT.

    The ADC's raw inputs are static pressure, total pressure and total air temperature.

  9. Q9

    Pitot blocked in climb, altimeter will?

    • AConstant
    • BOver
    • CUnder
    Show answer

    Correct answer: A. Constant

    Altimeter uses static pressure, not pitot. A blocked pitot doesn’t affect it, so it stays constant and accurate.

  10. Q10

    The total pressure head comprises a mast which moves its port to a distance from the aircraft skin in order?

    • ATo not disturb the aerodynamic flow around the aircraft
    • BTo locate it outside the boundary layer
    • CTo protect it from icing
    • DTo make it easily accessible during maintenance
    Show answer

    Correct answer: B. To locate it outside the boundary layer

    The pitot mast holds its port clear of the boundary layer to sense undisturbed total pressure.

  11. Q11

    Pitot partially blocked in climb, ASI will:

    • AAct like altimeter
    • BDecrease gradually
    • CIncrease
    Show answer

    Correct answer: A. Act like altimeter

    A partially blocked pitot traps pressure, so as static pressure drops in climb, ASI reads like an altimeter, showing a false increase.

  12. Q12

    The response time of a vertical speed detector may be increased by adding a?

    • ACorrection based on an accelerometer sensor.
    • BBi-metallic strip.
    • CReturn spring.
    • DSecond calibrated port.
    Show answer

    Correct answer: A. Correction based on an accelerometer sensor.

    Adding an accelerometer sensor creates the instantaneous VSI and improves its response time.

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