DGCA Air Navigation: Altimeters Questions

126 exam-style Altimeters 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

    The altimeter is subject to static pressure error. This error varies according to:

    • ATAS and altimeter setting.
    • BTAS and OAT.
    • CAngle of attack and OAT.
    • DTAS and angle of attack
    Show answer

    Correct answer: D. TAS and angle of attack

    Static pressure error varies with TAS and angle of attack.

  2. Q2

    During the approach, a crew reads on the radio altimeter the value of 650 ft. This is an Indication of the true?

    • AHeight of the lowest wheels with regard to the ground at any time.
    • BHeight of the aircraft with regard to the ground at any time.
    • CHeight of the aircraft with regard to the runway.
    • DAltitude of the aircraft.
    Show answer

    Correct answer: B. Height of the aircraft with regard to the ground at any time.

    A radio altimeter shows the aircraft's height above the ground at any time.

  3. Q3

    The altimeter is subject to static pressure error. This error results from:

    • AIncorrect pressure sensing caused by disturbance of airflow around the static ports,
    • BImperfect elasticity of the aneroid capsule.
    • CFriction inside the instruments.
    • DCabin pressure slightly lower than outside air pressure due to airflow over the fuselage.
    Show answer

    Correct answer: A. Incorrect pressure sensing caused by disturbance of airflow around the static ports,

    Static pressure error results from disturbed airflow around the static ports.

  4. Q4

    Altimeter is based on what?

    • ADifferential
    • BStatic
    • CTotal
    Show answer

    Correct answer: B. Static

    Altimeters measure static pressure from the atmosphere to determine altitude, adjusted to a reference like QNH.

  5. Q5

    An aircraft taking off from an airfield with QNH set in the altimeter has both static vents blocked by ice. As the aircraft climbs away the altimeter will:

    • ARead the airfield elevation
    • BIndicate the aircraft height amsl
    • CRead the height of the aircraft above the airfield
    • DShow only a very small increase in height
    Show answer

    Correct answer: A. Read the airfield elevation

    This Explanation is Coming Soon

  6. Q6

    The true altitude of an aircraft in flight is shown from:

    • Athe standard atmosphere
    • Bpressure altitude
    • Cdensity altitude
    • Dtemperature altitude
    Show answer

    Correct answer: B. pressure altitude

    This Explanation is Coming Soon

  7. Q7

    For most radio altimeters, when a system error occurs during approach the?

    • AHeight indication is removed.
    • BDH lamp flashes red and the audio signal sounds,
    • CDH lamp flashes red.
    • DAudio warning signal sounds.
    Show answer

    Correct answer: A. Height indication is removed.

    A system error removes the radio altimeter's height indication.

  8. Q8

    QNH is 1035 hPa, height of mountain is 10600 ft, minimum terrain clearance required is 1500 ft. What is the minimum flight level?

    • A130
    • B160
    • C120
    Show answer

    Correct answer: B. 160

    Required altitude = 10600 + 1500 = 12100 ft. QNH 1035 hPa is above standard 1013 hPa, so pressure altitude is lower. For simplicity, at 1035 hPa, 1 hPa ≈ 27 ft. Difference of 22 hPa × 27 ≈ 594 ft lower. Thus, 12100 + 594 ≈ 12694 ft pressure altitude. Nearest flight level above is FL130 (13000 ft), but FL160 ensures safe clearance.

  9. Q9

    A vibrator may be fitted to an altimeter to overcome:

    • Afriction
    • Bhysterysis
    • Clag
    • Dpressure error
    Show answer

    Correct answer: A. friction

    This Explanation is Coming Soon

  10. Q10

    The servo-assisted altimeter is more accurate than a simple altimeter because the small movements of:

    • AThe pointers are detected by a very sensitive electro-magnetic pick-off.
    • BThe capsules are detected by a very sensitive electro-magnetic pick-off.
    • CThe capsules are not taken into account.
    • DThe capsules are inhibited.
    Show answer

    Correct answer: B. The capsules are detected by a very sensitive electro-magnetic pick-off.

    A sensitive electro-magnetic pick-off detects the small capsule movements, improving accuracy.

  11. Q11

    An aircraft is flying at constant indicated altitude, over a warm airmass. The altimeter reading will be:

    • Acorrect
    • Bgreater than the real altitude
    • Cless than the real altitude
    • Doscillating around the correct altitude
    Show answer

    Correct answer: C. less than the real altitude

    This Explanation is Coming Soon

  12. Q12

    What is Density Altitude?

    • Atemperature altitude
    • Bpressure altitude corrected for the prevailing temperature
    • Cthe altitude in the International Standard Atmosphere at which the prevailing density would be found
    • Dpressure altitude corrected for Total Air Temperature
    Show answer

    Correct answer: C. the altitude in the International Standard Atmosphere at which the prevailing density would be found

    This Explanation is Coming Soon

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