5464. The aircraft radio equipment which emits on a frequency of 4400 MHz is the: A – primary radar
B – high altitude radio altimeter C – weather radar
D – radio altimeter Ref: all
Ans: D
5535. The data supplied by a radio altimeter: A – concerns only the decision height
B – indicates the distance between the ground and the aircraft C – is used only by the radio altimeter indicator
D – is used by the automatic pilot in the altitude hold mode Ref: all
Ans: B
5543. In low altitude radio altimeters, the height measurement (above the ground) is based upon:
A – a triangular amplitude modulation wave, for which modulation phase shift between transmitted and received waves after ground reflection is
measured
B – a pulse transmission, for which time between transmission and reception is measured on a circular scanning screen
C – a wave transmission, for which the frequency shift by DOPPLER effect after ground reflection is measured
D – a frequency modulation wave, for which the frequency variation between the transmitted wave and the received wave after ground reflection is measured
Ref: all Ans: D
5613. A radio altimeter can be defined as a:
A – self contained on board aid used to measure the true height of the aircraft B – ground radio aid used to measure the true altitude of the aircraft
C – ground radio aid used to measure the true height of the aircraft
D – self contained on board aid used to measure the true altitude of the aircraft Ref: all
Ans: A
5645. Modern low altitude radio altimeters emit waves in the following frequency band:
A – HF (High Frequency) B – VLF (Very Low Frequency) C – SHF (Super High Frequency) D – UHF (Ultra High Frequency) Ref: all
Ans: C
5661. The operation of the radio altimeter of a modern aircraft is based on: A – amplitude modulation of the carrier wave
B – frequency modulation of the carrier wave C – pulse modulation of the carrier wave
D – a combination of frequency modulation and pulse modulation Ref: all
Ans: B
5672. During the approach, a crew reads on the radio altimeter the value of 650 ft. This is an indication of the true:
A – height of the aircraft with regard to the ground at any time B – height of the lowest wheels with regard to the ground at any time C – height of the aircraft with regard to the runway
D – altitude of the aircraft Ref: all
5712. A radio altimeter is:
A – ground based and measures true altitude B – ground based and measures true height C – aircraft based and measures true altitude D – aircraft based and measures true height Ref: all
Ans: D
5735. In low altitude radio altimeters, the reading is zero when main landing gear wheels are on the ground. For this, it is necessary to:
A – change the display scale in short final, in order to have a precise readout B – place the antennas on the bottom of the aeroplane
C – account for signal processing time in the unit and apply a correction factor to the reading
D – compensate residual altitude due to antennas height above the ground and coaxial cables length
Ref: all Ans: C
5744. For most radio altimeters, when a system error occurs during approach the… A – DH lamp flashes red and the audio signal sounds
B – Height indication is removed C – DH lamp flashes red
D – Audio warning signal sounds Ref: all
5785. 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 4) 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:
A – 1, 3, 4, 5 B – 3, 5 C – 1, 2, 4, 5 D – 1, 3, 5 Ref: all Ans: B
5799. The operating frequency range of a low altitude radio altimeter is: A – 420 MHz to 440 MHz B – 460 MHz to 480 MHz C – 4200 MHz to 4400 MHz D – 4.6 GHz to 4.8 GHz Ref: all Ans: C
11207. A radio signal has a frequency of 3 GHz. Its wave length is: A – 100 cm B – 1.0 cm C – 10 cm D – 1.0 m Ref: all Ans: C
20178. The operating frequency range of a low altitude radio altimeter is: A – 2700 MHz to 2900 MHz B – 5 GHz C – 4200 MHz to 4400 MHz D – 5400 MHz or 9400 MHz Ref: all Ans: C
20511. A radio altimeter uses:
A – four antennas: two for the transmission and two for the reception B – two antennas: one for the transmission and another for the reception C – two antennas: both of them for simultaneous transmission and reception D – a single antenna for simultaneous transmission and reception
Ref: all Ans: B
20761. The Low Altitude Radio Altimeter uses the following wavelengths: A – myriametric B – centimetric C – decimetric D – metric Ref: all Ans: B
20786. The radio altimeter is required to indicate zero height AGL as the main wheels touch down on the runway. For this reason, it is necessary to:
A – have a specific radio altimeter dedicated to automatic landing B – adjust the gross height according to the aircraft instantaneous pitch C – change the display scale in short final, in order to have a precise readout D – compensate for residual height and cable length
Ref: all Ans: D
20787. The radio altimeter:
1) operates in the 1600-1660 KHz range 2) operates in the 4200-4400 MHz range 3) measures a frequency difference 4) measures an amplitude difference
The combination regrouping all the correct statements is: A – 1 and 4 B – 2 and 4 C – 1 and 3 D – 2 and 3 Ref: all Ans: D
20788. The range of a low altitude radio altimeter is: A – 500 ft B – 2500 ft C – greater than 10000 ft D – 10000 ft Ref: all Ans: B
24803. If the radio altimeter fails:
A – height information disappears B – aural warning is given
C – radio alt flag, red lamp, and aural warning are given D – radio alt flag and red lamp activate
Ref: all Ans: A
24817. What does a radio altimeter, for an aircraft in the landing configuration, measure?
A – height of aircraft wheels above the ground B – height of the aircraft above the ground C – altitude of the aircraft
D – altitude of the aircraft wheels Ref: all
Ans: A
24818. What principle does the radio altimeter work on? A – pulse modulation
B – amplitude modulation
C – pulse modulation and carrier wave D – frequency modulation and carrier wave Ref: all
Ans: D
24829. What aircraft system uses a frequency of 4400 MHz? A – SSR B – radio altimeter C – weather radar D – ATC radar Ref: all Ans: B
24830. A low altitude Radio Altimeter, used in precision approaches, has the following characteristics:
1) 1540 MHz to 1660 MHz range 2) pulse transmissions
3) frequency modulation
4) height range between 0 and 5000 ft
5) an accuracy of +/- 2 ft between 0 and 500 ft A – 1, 4, 5 B – 3, 4 C – 3, 5 D – 2, 3, 5 Ref: all Ans: C
24836. What is the normal operating range of a low altitude Radio Altimeter? A – 0 to 5000 ft B – 0 to 2500 ft C – 0 to 10000 ft D – 0 to 7500 ft Ref: all Ans: B
24837. What is a radio altimeter used for?
A – to determine aircraft height above mean sea level B – to determine aircraft height above ground level C – to determine pressure altitude
D – to determine aircraft altitude Ref: all
Ans: B
24851. A typical radio altimeter wave length and frequency band is: A – 0.1895 m UHF B – 6.9 cm SHF C – 3.41 m UHF D – 7.1 m EHF Ref: all Ans: B