RADIO ALTIMETER – Air – DGCA Question Bank For Politics

#1. During the qpproach, a crew reads on the radio altimeter the value of 650 ft. The is an indication of the true?

Height of the lowest wheels with regard to the ground at any time.

Height of the aircraft with to the ground at a any time.

Height of the aircraft with regard to the runway.

Altitude of the aircraft.

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

Height indication is removed.

DH lamp flashes red and the audio signal sounds.

DH lamp flashes red.

Audio warning signal sounds.

#3. A radio altimeter can be defined as a?

Ground radio aid used to measure the true height of the aircraft.

Ground radio aid used to measure the true altitude of the aircraft.

Self-contained on-board aid used to measure the true height of the aircraft.

Self-contained on-board aid used to measures the true altitude of the aircraft.

#4. The data supplied by a radio altimeter?

Indicates the distance between the ground and the aircraft.

Concerns only the decision height.

Is used only by the radio altimeter indicator.

Is used by the automatic pilot in the altitude hold mode.

#5. The low-altitude radio altimeters used in precision approaches: 1.Operate in the 1540-1660 MHz range. 2.Are of the pulsed type. 3. Are of the frequency modulation type. 3. Have an operating range of 0 to 5000 ft. 5. Have a precision of +/-2 feet between 0 and 500 ft. The combination of the correct statements is?

3,5.

3,4.

2,3,4.

1,2,5.

#6. In low altitude ratio altimeters, the reading is zero when main landing gear wheels are on the ground. For this, it is necessary to?

Change the display scale in short final, In order to have a precise readout.

Compensate residual altitude due to antennas height above above the ground and coaxial cable length.

Account for signal processing time in the unit and apply a correction factor to the reading.

Place the antennas on the bottom of the aeroplane.

#7. The operating frequency range of a low altitude radio altimeter is?

2700 MHz to 2900 MHz.

5 GHz.

4200 MHz to 4400 MHz.

5400 MHz or 9400 MHz.

#8. Modern low altitude radio altimeters emit waves in the following frequency band?

HF (High Frequency).

UHF (Ultra High Frequency).

SHF (Super High Frequency).

VLF (Very Low Frequency).

#9. The operation of the radio altimeter of a modern aircraft is based on?

Pulse modulation of the carrier wave.

A combination of frequency modulation and pulse modulation.

Frequency modulation of the carrier wave.

Amplitude modulation of the carrier wave.

#10. In low altitude radio altimeters height measurement (above ground) is based upon?

A triangular amplitude modulation wave, for which modulation phase shift between transmitted and received waves after ground reflection is measured.

A frequency modulation wave, for which the frequency variation between the transmitted wave and the received wave after ground reflection is measured.

A pulse transmission, for which time between transmission and reception is measured on a circular scanning screen.

A wave transmission, for which the frequency shift by DOPPLER effect after ground reflection is measured.

#11. The aircraft radio equipment which emits on a frequency of 440 MHz is the?

Weather radar.

Primary rada.

Radio altimetter.

High altitude radio altimeter.

#12. A radio altimeter is?

Aircraft based and indicates true altitude.

Aircraft based and indicates pressure altitude.

Aircraft based and indicates true beight.

Ground based and employ microwaves.

#13. Radio altimeters are based on the principle of?

Frequency modulated carrier wave.

Pulse modulated carrier wave.

Amplitude modulated carrier wave.

Continuous wave.

#14. For the landing configuration a radio altimeter indicates?

Height of the aircraft above the ground.

Height of the flight deck above the ground.

Height of the main wheel above the ground.

Altitude.

#15. Low altitude radio altimeters operate on the ___________wavelength?

Metric

Centimetric

Decimetric

Millimetric

#16. Low altitude altimeters use the __________ waveband?

HF

VHF

UHF

SHF.

#17. If there is a fault in the system the radalt display will?

Needle will disappear and an alarm flag will appear, possibly accompanied by an audio warning.

Freeze.

True red and activate an aural warning.

Turn red and activate visual and aural warnings.

#18. A radio altimeter measures?

True Altitude.

Pressure altitude.

Height above sea level.

Height above the ground or water over which the aircraft if flying

#19. A radalt is?

Ground based and measures true altitude.

Ground based and measures true height.

Aircraft based and measures true altitude.

Aircraft based and measures true height.

#20. A RADALT provides?

Radio altitude.

Pressure altitude.

Density altitude.

Height above terrain.

#21. The failure of the radio altimeter would cause?

Loss of pressure altitude data.

Loss of density altitude data.

Loss of altitude data.

Loss of height data.

#22. A radio altimeter has a maximum effective height because?

At greater heights the signal will be too weak.

At greater heights the signal will be undetectable.

At greater heights the signal will be absorbed by moisture in the air

At greater heights signal from different modulation cycles will overlap.

#23. Radio altimeters work on the principal of?

Frequency modulation.

Amplitude modulation.

Pulse modulation.

Pulse the amplitude modulation.

#24. A RADALT employs _________ waveband?

HF.

VHF.

UHF.

SHF.

#25. Radio altimeters employ?

FM.

AM.

Pulsed FM.

Pule modulation.

#26. A radio altimeter will indicate zero when the aircraft is on the ground because of? 1. Frequency modulation of the transmitted signal. 2. Allowance for the signal path through the aircraft. 3. Allowance for the height of the aerials above the main wheels. 4. Beam width compensation. 5. Reducation in gain rate very close to the surface.

1, 2.

2, 3.

3, 4.

4, 5.

#27. Radio altimeters are accurate only within the height range?

Zero to 50 ft.

Zero to 500 ft.

50 ft to 2700 ft.

Zero ft to 2500 ft.

#28. The frequency range used by a low altitude radio altimeter is?