11 Area Navigation (RNAV)

Question 1

What does RNAV stand for?

Answer 1

Area Navigation

Question 2

What is Area Navigation (RNAV)?

Answer 2

• Method by which an AC can fly any flight path (not just from ground station to ground station) by the use of:
• Station based navigation systems (VOR, DME, GNSS)
• Internal navigation systems (INS, IRS)
• Whilst maintaining suitable accuracy and reliability

Question 3

Describe a Phantom Waypoint

Answer 3

• Defined by either:
• A bearing and distance from a ground station (VOR etc.)
• GPS position (Lat and Long)
• Designated by a 5 letter word
• Don’t require a physical ground station

Question 4

Describe the following types of RNAV:

• 2d
• 3d
• 4d

Answer 4

• 2d: Lateral navigation only (VOR / DME)
• 3d: Lateral and vertical navigation (Above + ADC / Altimeter / GNSS)
• 4d: Lateral, vertical and time navigation

Question 5

What is Kalman Filtering?

Answer 5

• Process of weighing different sources of location data and comparing them accordingly
• The final location is then presented

Question 6

What are the location sources used by RNAV (in order of priority)?

Answer 6

• GNSS
• INS / IRS
• VOR / DME
• VOR / VOR
• DME / DME

Question 7

What is the cross track distance (XTK-distance) in an area navigation system?

Answer 7

Distance between the actual position and the great circle track between active waypoints

Question 8

What are the key bits of information required when using Waypoints?

Answer 8

• Crosstrack distance

- Distance to waypoint

Question 9

What give the best information about the progress of a flight between 2 en-route waypoints from RNAV equipment?

Answer 9

ETO - Estimated time overhead

Question 10

What is the full scale deflection on an HSI for an RNAV system in:

• En-route mode
• APP mode

Answer 10

• En-route: 5nm

- APP: 1.25nm

Question 11

Where on an RNAV system is the Cross Track Distance displayed?

Answer 11

Navigation Display