Aircraft navigation systems

Question 1

What is needed for visual navigation?

Answer 1

The “old school” method! Requires:
1 x compass
1 x stopwatch
1 x map
1 x pair of eyeballs
Sufficient visibility and high enough cloud base

Question 2

What is visual navigation also referred to as?

Answer 2

It is also referred to as dead reckoning

Question 3

What pole do aircraft navigation systems use?

Answer 3

The magnetic north pole, and this is different to the true north pole

Question 4

What causes the magnetic north pole to move over time?

Answer 4

Flux lobe elongation

Question 5

What is NDB

Answer 5

Non-directional beacon (NDB) – a ground-based, low frequency radio transmitter used as an instrument approach for airports

Question 6

What is ADF

Answer 6

Automatic direction finding (ADF) – an instrument that automatically and continuously displays the relative bearing from the aircraft to a tuned radio station

Question 7

When finding out position, why is it important to use more than one beacon?

Answer 7

Using 2 or more beacons we can draw lines to figure out our exact position; this cannot be done with only one beacon

Question 8

What are some situations that can cause errors to the NDB?

Answer 8

• Coastal refraction
• Dip
• Static interference

Question 9

What is DME

Answer 9

Distance measuring equipment (DME) – a combination of ground and airborne equipment which gives a continuous slant range distance-from-station readout bymeasuringtime-lapse of a signal transmitted by the aircraft to the station and responded back

Question 10

What is VOR

Answer 10

Very high frequency omnidirectional range (VOR) – a short-range radio navigation system for aircraft, enabling aircraft with a receiving unit to determine its position and stay on course by receiving radio signals transmitted by a network of fixed ground radio beacons

Question 11

What is HSI

Answer 11

Horizontal situation indicator (HSI) – an instrument to determine which radial you are on

Question 12

What are airways (when talking about air traffic control)

Answer 12

Corridors in the sky used by air traffic control (ATC) to guide aircraft from point to point

Question 13

What is GPS

Answer 13

Global Positioning System (GPS) – a satellite-based radio navigation system that provides geolocation and time information to a GPS receiver anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites

Question 14

What is ILS

Answer 14

Localiser provides horizontal guidance

Glideslope provides vertical guidance

Question 15

How does a pilot land the aircraft when there is very poor visibility

Answer 15

In very bad visibility pilots are not permitted to land the aircraft
If the aircraft is capable and certain systems are functioning, the autopilot can perform the landing and roll-out

Question 16

What is INS

Answer 16

Inertial Navigation System (INS) – a navigation device that uses a computer, accelerometers and gyroscopes to continuously calculate the aircraft’s position, orientation and velocity without the need for external references

Question 17

What are potential problems with inertial navigation?

Answer 17

Over time, systems suffer from drift due to repeated integrations of acceleration and angular velocity
Small errors → big errors over the course of a many hour flight

Question 18

How can you deal with inertial navigation errors?

Answer 18

The computers can use previous calculations and calculate averages to estimate where you are. These calculations can also be backed up by other sources, e.g. VOR, DME, GPS

Question 19

What is the flight management system useful for?

Answer 19

It has a world database on:
Airways
Airports
Navaids
SIDs/STARs
Approach procedures

Question 20

What is STAR

Answer 20

Standard terminal arrival (STAR) – a published flight procedure followed by aircraft on an instrument flight rules (IFR) flight plan just before reaching a destination airport