NAV - Eurocontrol PBN

Question 1

What is PDE? (4)

Answer 1

PDE - Path Definition Error

• A defined path may not exactly match with the desired path
• Caused by the resolution of the computer and irregular Surface
• This is a small error managed in the data chain

Question 2

What is NSE? (3)

Answer 2

NSE - Navigation Sensor Error

• A/Cs actual position may not coincide with its estimated position, minimised by using more accurate position sensors
• Represents the difference between the true position and estimated position

Question 3

What is FTE? (3)

Answer 3

FTE - Flight Technical Error

• Ability of Pilot or Avionics to fly from estimated position onto the defined path
• Can be minimised by the use of flight director or Autopilot

Question 4

What is TSE? (4)

Answer 4

TSE - Total System Error

• Combination of all 3 errors
• TSE is the difference between physical true position and the desired path
• +/- 1nm for 95+% of flight time

Question 5

PDE, NSE, FTE, TSE diagram

Answer 5

Question 6

What is LNAV / VNAV? (2)

Answer 6

Lateral Navigation
Vertical Navigation

Estimated position onto the defined path

Question 7

What is a Waypoint? (4)

Answer 7

• Defined geographical coordinate (WGS84)
• 5 letter unique code. e.g. GROVE
• 3 letter code - Nav aid. e.g BHX
• Terminal airspace - Alphanumeric code. e.g. BB155

Question 8

What is FRT? (5)

Answer 8

FRT - Fixed Radius Transition

• Enroute functionality
• Used for other ATS routes (higher altitudes)

Recommended turn radius:
- 22.5nm above F200
- 15nm below F190

Question 9

What is a Path Terminator? (3)

Answer 9

• Associated with each leg of Instrument Flight Procedures (IFP)
• Defines how the path will be flown and how the leg will be terminated
• RF (Radius to Fix) is used for consistent turn performance on IFPs

Question 10

What is a Fly-by turn? (4)

Answer 10

• Aircrafts RNAV system anticipates the turn
• Turn starts at some distance before WP to allow tangential interception of the next leg
• Majority of A/C have this functionality
• Earliest turn can be initiated is 20nm prior to WP

Question 11

What is a Fly-Over turn? (3)

Answer 11

• Aircraft starts to turn on the next leg as it passes over the WP
• All A/C capable of this functionality
• Causes A/C to overfly route > confliction with parallel aircraft / routes

Question 12

Fly-by & Fly-over diagram

Answer 12

Question 13

What is a Parallel offset (RNAV)? (3)

Answer 13

• A parallel track to the left or right of designated or established airway/route
• Only used during Enroute phase
• Can achieve lateral separation or avoid wake turbulence (Alternative to vectoring)