Block One

Question 1

Explain the operation, function, advantages and disadvantages of a Non-Directional Beacon (NDB)

Answer 1

Emit a non-directional signal with a range of about 25 miles. The radio receiver in the aircraft that gets signals from NDBs is an Automatic Direction Finder (ADF)
Used for: enroute navigation, holding facility, IFR approach, fix determination
Disadvantages: subject to meterological interference, not as accurate as some other navaids
Homing is when the pilot keeps the ADF needle at straight ahead and eventually arrives at the station. Tracking adjusts for wind drift flies directly to the station.

Question 2

Explain the operation, function, advantages and disadvantages of a VHF Omni-range (VOR)

Answer 2

Forms the backbone of current air navigation systems.
Like an electronic wagon wheel that radiates 360 spokes or courses. The spokes are called radials
Used for: enroute navigation, holding fix, IFR approach, determination of intersection
Advantages: little interference, 360 degrees, accuracy +/- 2 degrees, easy to use, good reception distance
Disadvantages: line of sight characteristics, interference with radio transmitters

Question 3

Explain the operation, function, advantages and disadvantages of Distance Measuring Equipment (DME)

Answer 3

Gives distance from the transmitter. Distance given is the slant range. Accuracy of +/- 0.5NM
Requires airborne and ground equipment.
Advantages: Longitudinal separation may be reduced to 20 NM (where radar not available), provides continuous position information to the pilot, provides DME arcs to an IFR approach (removing the need for procedure turns), DME positions on non-precision approaches result in lower limits because exact position on final can be determined.

Question 4

Explain the operation, function, advantages and disadvantages of TACAN / VORTAC

Answer 4

TACtical Air Navigation System is primarily a military system although civilians can use its DME
VOR and TACan (VORTAC) provides bearing and range (DME) information

Question 5

Explain the operation, function, advantages and disadvantages of Instrument Landing System (ILS)

Answer 5

ILS is a precision approach aid. It was designed to provide approach path with exact alignment and decent of an aircraft on final approach. ILS has been popular since the 1950s. Current technology allows safe landings with 0 visibility and 0 ceiling. The ILS includes a localizer (lateral guidance) and glide path (vertical guidance) and NDB (when the pilot flies over an NDB they will know how far it is to the runway).
The localizer transmits a beam in the opposite direction from the airport (the back course) - the pilot flies away from the CDI (Course Deviation Indicator) to maintain a centre line). On front course approact the pilot flies to the needle.
The ILS has a designated critical area around the localizer and glide path antenna where vehicles present may distort the signal. Vehicles must be kept away from these areas when approaches are in progress.

Question 6

Explain the operation, function, advantages and disadvantages of Area Navigation Systems (RNAV)

Answer 6

RNAV is a method of navigation which permits aircraft operation on any desired path within the coverage of ground or space-based NAVAIDS or within the limits of self-contained aids or a combination of these.

Question 7

State the rules regarding equipment operation

Answer 7

Test all of the equipment used to provide ATC service at the beginning of every shift.
Do not tamper or interfere with the normal operating status of equipment.
If you detect an equipment malfunction a) immeadiately report it in accordance with unit procedures and b) do not use the equipment if the malfunction could creat a hazardous situation.
Co-ordinate release of equipment for routine maintenance with appropriate personnel taking into account requirements for current and anticipated traffic during the interruption. Make every effort to release equipment for routine maintenance when requested.
Keep fully informed of the operational status of airport equipment used by aircraft of ATC.
Display the current status, if other than normal, to attract the attention of concerned personnel.

Question 8

State the procedures for the shutdown of radio aids

Answer 8

A) Approve if: no known IFR traffic will be affected by the shutdown OR there is IFR traffic but they can use other available facilities OR traffic can be controlled safely and efficiently with other available facilities
B) Delay if: traffic cannot be controlled safely and effeciently using other facilities for a short period of time OR a pilot or operator has indicated a requirement to have the facility available for a short specified period of time.
C) Disapprove if: traffic cannot be controlled safely and effeciently using other facilities for an extended period of time OR a request has been made to have the facility available for an extended period of time.

Prior to the shutdown the FSS or control tower will contact the ACC for approval to shutdown the radio aid.

Question 9

State the procedures for reporting unserviceabilities

Answer 9

Report promptly any equipment unserviceability or malfunction to:
A) the appropriate manager
B) the section/agency responsible for maintenance
C) both A and B

The TOC (Technical Operation Co-ordinator), located in ACC, is the central reporting agency for all malfunctions.

Facilities are assigned a maintenance response time based on the impact of the failure. Response times assigned are for a technician to arrive at the site, ready to begin repairs.

Question 10

State the unit rules pertaining to unit clocks

Answer 10

Managers shall establish procedures to ensure that unit clocks are indicating the correct time AND time-of-day clocks in automated systems are indicating the correct time if the time is included in recordings or printouts OR the time is displayed at operating positions
If an ATS unit is connected to a “Master-Slave” system the maintenance facility may be responsible fore ensuring the accuracy of the “Master” clock
If the setting of the clock is a maintenance responsibility, it will be necessary to inform the appropriate maintenance personnel of any observed error.
Time checks from the following services are acceptable a) radio station CHU on 3330, 7850 or 14670 KHz, b) radio station WWV on 2.5, 5, 10, 15 or 20 MHz, c) the local telephone system if the automatic transmission of time is available

Question 11

Explain the relationship between frequency and wavelength

Answer 11

Frequency and wavelength are inversely proportional. A higher frequency means a shorter wavelength and a longer wavelength means a lower frequency.

Question 12

Decode the following: kHz, MHz, VLF, LF, MF, HF, VHF, UHF

Answer 12

VLF Very Low Frequency <30 kHz, metres
LF Low Frequency 30-300 kHz metres
MF Medium Frequency 300-3000 kHz metres
HF High Frequency 3000-30000 kHz metres
VHF Very High Frequency 30-300 MHz centimetres
UHF Ultra High Frequency 300-3000 MHz centimetres

Question 13

Describe the characteristics of LF/MF/HF signals.

Answer 13

LF, MF and HF travel as A) Ground Waves which follow the surface of the Earth due to diffraction. Waves in the kHz range bend around obstacles and after repeated bending follow the curvature of the Earth AND B) Sky Waves which travel up into the atmosphere and are reflected by the ionosphere meaning they can be heard at distances far beyond the range of ground waves.

Question 14

Describe the characteristics of VHF/UHF signals.

Answer 14

VHF and UHF signals travel only by line of sight. As a result the higher the aircraft the greater the distance at which it will receive VHF signals. Stations below the horizon, only a few hundred kms apart do not interfere with each other. These frequency are also virtually free from atmospheric and precipitation static.

Question 15

Describe the theory of frequency range and the difference between ground and aircraft range.

Answer 15

VHF and UHF frequencies are principally used for voice communication because of the lack of interference from atmospheric conditions. Because they are line of sight the altitude of an aircraft affects the distance the signal will travel. Air to air communications have about double the range of air to ground communications.

eg at FL 180 range is 90 NM and 180 NM
FL350 125 NM and 250 NM
FL450 142 NM and 284 NM
(ground and air-to-air respectively. Assumes both aircraft are at same altitude for air-to-air)

Question 16

List the common uses for LF/MF

Answer 16

LF/MF f=30-3000kHz used for NDBs and commercial broadcasting

Question 17

List the common uses for HF

Answer 17

HF 3000-30000 kHz used for Northern areas, primarily long range communications

Question 18

List the common uses for VHF

Answer 18

30-300 MHz primarily ATS band for air/ground communications, also used for ILS localizer and VOR

Question 19

List the common uses for UHF

Answer 19

300-3,000 MHz psed for militariy air/ground communications, ATS and defence radar, DME, TACAN and ILS glide path. The military is phasing the use of UHF ground/air in favour of VHF

Question 20

State the range of frequencies available to ATS

Answer 20

NDB 190 - 415 kHz, 510 - 535 kHz
DME 90 - 1,215 MHz
ILS 108.1 - 111.9 MHz
VOR 112.1 - 117.9 MHz
Voice comms 118 to 136 MHz
Radar 300 MHz - 1GHz

Question 21

Describe how a 25 kHz spacing is utilized and communicated when a frequency is transmitted.

Answer 21

The VHF band for civilian aircraft communications is 118 MHz to 136 MHz. Historically VHF channels were spaced by 0.100 MHz channels. Spacing has been reduced to 0.025 MHz between channels. However most airborne equipment only displays to the tens of kHz, eg 118.12 and have no room to display the last digit in 0.025 MHz spaced frequencies.
Thus frequencies are given to 5 significant figures and the last 5 (if there as in 112.125 or 112.175) is dropped. Do not round up, simply omit the last digit.
eg 112.125 –> 112.12

Question 22

State the goal of the ATC radio frequency audit

Answer 22

he goal of the frequency audit was to investigate and determine the effectiveness of NAV CANADA’s ability to allocate and re- allocate frequencies. The ultimate goal was to get more radio assignments for ATC where it is presently difficult to do so. Congestion and associated problems are most significant in Vancouver, Toronto and Montreal.

Question 23

Describe Frequency Protected Service Volume (FPSV)

Answer 23

Agreements regarding the “volume of airspace” (sector, CZ, etc) particular frequencies will serve are reached with ALL REGULATOR AGENCIES AND USERS IN NORTH AMERICA. The volume is then protected by the agreement and refered to as a FPSV (Frequency Protected Service Volume)
FPSVs usually conform to sector boundaries (which is less than the actual coverage capability
The reason for assignments based on FSPV is to increase the reuse potential of ATC radio channels.

Question 24

Describe 3 modes of data link communication

Answer 24

Mode S secondary surveillance radar provides two-way data communications for air traffic, flight information and surveillance services. Each aircraft is addressed individually and gives ID, altitude and data. The ability to send data back and forth allows controllers to keep track of the aircraft's position and route.
Satellite communications (SATCOM) is used for communications in the oceanic environment and remote areas.
VHF data link is widely used for aircraft operations and limited flight information and ATS, such as pre-departure clearance, ATIS info, altimeter info, runway assignment etc. Graphical weather service provides weather graphics information derived from ground based weather radar. The information is displayed on a cockpit control and display unit.