Ratel

Question 1

What does a transponder do?

Answer 1

Enables a ground base radar controller or a pilot with an ACAS to determine the location (and altitude) of an aircraft

Question 2

What is an ACAS

Answer 2

Airbourne Collision Avoidance System. fitted to another AC

Question 3

How does a transponder work

Answer 3

a signal sent from a ground based rader unit is received by the transponder (interrogates the transponder). the signal triggers the transponder to send a coded signal back to the radar unit

Question 4

sound waves travel at what speed

Answer 4

the speed of sound

Question 5

what factor influences the speed of sound

Answer 5

air temperature

Question 6

what is the definition of frequency

Answer 6

the rate of recurrence of a vibration, an oscillation or a cycle (past a given point)

Question 7

how is wave motion described

Answer 7

by its shape and frequency

Question 8

how do radiowaves (electromagnetic waves) differ from sound waves

Answer 8

• variations in the strength of electric and magnetic fields, which do not require a medium
• radiowave distances are substantially greater
• rw travel at the speed of light

Question 9

how can the characteristics of a waveband be defined

Answer 9

wavelength, frequency, amplitude, frequency bands

Question 10

what is wavelength

Answer 10

length of a single wave or one completed cycle

Question 11

what is frequency

Answer 11

number of completed waves passing a point in one second

Question 12

what is amplitude

Answer 12

distance from the top or bottom of the wave to the mean value line of a wave

Question 13

why do we use the VHF band for aeronautical comms?

Answer 13

• large number of freuqncies

- reception is superior

Question 14

what is a disadvantage of VHF band for aeronautical comms

Answer 14

inability of signals to bend around obstacles. line of sight

Question 15

why would you be able to get a hf signal if you were in the lee of a mountain

Answer 15

sky waves- the propagation of radio waves reflected or refracted back toward Earth from the ionosphere, an electrically charged layer of the upper atmosphere

Question 16

what is a transceiver

Answer 16

a receiver and a transmitter

Question 17

what are the types of modulation and whats the difference

Answer 17

amplitude modulation- varying the amplitude while frequency remains constant
frequency modulation- vice versa

Question 18

what are the advantages of fm modulation over am

Answer 18

clearer signals

greater availability of channels within a given range of frequencies

Question 19

all ac in nz are fitted with 2 radios. what are they

Answer 19

transponder, elt

Question 20

what is mode
a
c

Answer 20

a- four figure code (predetermined for a class of ac, issued to you by control, permanent discrete code issued)
c- four figure code plus altitude

Question 21

transponder codes
off
sby
on
alt 
test

Answer 21

off- off
sby- transponder switched on but will not reply to interrogations
on-will reply to interrogations but will send mode A only
alt- transponder on, will reply. Mode A and C will be sent
Test- test function

Question 22

transponder codes
7500
7600
7700

Answer 22

7500- unlawful interference/ hijacking
7600- communications failure
7700- emergency- distress

Question 23

2 major disadvantages of hf

Answer 23

static interference and signal fading

Question 24

sound waves passing through air consists of …. being compressed and expanded; they move at the speed of ….

Answer 24

air, speed of sound

Question 25

radio waves are .... waves; they move at the speed of ...

Answer 25

electromagnetic, light

Question 26

amplitude means the distance between - top of wave to the bottom of the wave or - top or bottom of the wave to the mean value line

Answer 26

top or bottom of the wave to the mean value line

Question 27

what is meant by the term attenuation

Answer 27

weakening or decaying

Question 28

when radio waves are in the vhf band they have a longer/shorter wavelengths than in the lf band

Answer 28

shorter

Question 29

the preferred frequency band in aviation is ....

Answer 29

vhf

Question 30

what is mean by the term transceiver

Answer 30

transmitter/receiver

Question 31

what is meant by the term nav/com

Answer 31

combined radio installation for navigation aids and communications

Question 32

what is an important negative aspect of vhf transmission/reception

Answer 32

comparatively short range, line of sight

Question 33

flying higher/lower will improve range of vhf reception

Answer 33

higher

Question 34

range of vhf reception in nz has been improved by the installation of

Answer 34

repeater stations

Question 35

what is meant by the term modulation

Answer 35

superimposing of intelligence on the carrier wave

Question 36

when you press the microphone transmit button, the radio transmits the ... and when you speak into the microphone you add ... to it

Answer 36

carrier wave, modulation

Question 37

what happens if you activate your transmitter when another station is transmitting

Answer 37

you cut out other transmitions

Question 38

what is the function of the squelch control

Answer 38

to control the level of unwanted signals or static

Question 39

list two important steps before you transmit a message

Answer 39

formulate the message, listen for others

Question 40

compared to normal conversation what should be your rate of speech during transmitting

Answer 40

slightly slower, conversational

Question 41

what is the predominant advantage of hf over vhf and what is the predominant disadvantage

Answer 41

greater range. presence of static and fading

Question 42

when you see a short 50-80cm antenna, what frequency band is the radio likely to operate in

Answer 42

vhf

Question 43

after engine start you should select .... on your transponder and select .... or ..... for in flight conditions

Answer 43

sby, on, alt

Question 44

when you turn the transponder function switch on, the equipment transmits mode ..... information which does/does not include altitude information

Answer 44

mode a, does not

Question 45

when you are instructed to squawk ident you should

Answer 45

press the transponder ident button once