Intercepting and Tracking Navigational Systems and Arcs


Gain the skills associated with intercepting and tracking navigation aids and arcs solely by reference to instruments.


This is the required reading for this lesson. Numbers in [brackets] indicate the starting and ending page in the referenced reading material. Read all the pages and sections referenced.

  • Instrument Flying Handbook
    • Chapter 9 - Navigation Systems
      • [9-3 to 9-35] "Traditional Navigation Systems" to "Advanced Technologies"


The notes below highlight the important parts in the referenced material. Reading the notes without having read the actual referenced material is generally not sufficient to pass the written exam!

IFH - Chapter 9

  • Nondirectional Radio Beacon (NDB)
    • Automatic Direction Finder (ADF) points to the NDB
    • NDB - 190 to 555 kHz
    • AM radio stations - 550 to 1650 kHz
    • ADF Homing
      • Keeping needle pointing directly at the NDB
    • ADF Tracking
      • Flying a heading that maintains the desired track to or from the station regardless of crosswind conditions
  • Very High Frequency Omnidirectional Range
    • Transmits azimuth information to the aircraft, providing 360 courses TO or FROM the VOR station
    • When DME is installed with the VOR, it is referred to as a VOR/DME
      • Provides both azimuth and distance information
    • When military tactical air navigation (TACAN) equipment is installed with the VOR, it is known as a VORTAC
      • Provides both azimuth and distance information
    • Omnibearing Selector (OBS)
      • Selects the desired course
    • Course Deviation Indicator (CDI)
      • Consists of instrument face and needle
      • Full needle deflections indicates 12 or more degrees off course
    • TO/FROM Indicator
      • Shows whether the selected course, if intercepted and flown, takes the aircraft TO or FROM the station
      • Does not indicate whether the aircraft is heading to or from the station.
  • Distance Measuring Equipment (DME)
    • Used for determining the distance from a ground DME transmitter
    • Can be used to fly DME Arcs
  • Area Navigation (RNAV)
    • RNAV equipment includes
      • VOR/DME
      • LORAN
      • GPS
      • Inertial navigation systems (INS)
  • Global Navigation Satellite System (GNSS)
    • Three systems:
      • GPS, a United States system
      • GNSS (GLONASS), a Russian system
      • Galileo, a European system
    • Based on the concept of ranging and triangulation
      • Needs at least four satellites to yield a three-dimensional position
    • Verification of signal integrity
      • Receiver autonomous integrity monitoring (RAIM)
    • Aircraft using GPS navigation equipment under IFR must be equipped with alternate means of navigation appropriate to the flight
  • Differential Global Positioning Systems (DGPS)
    • Designed to improve accuracy by measuring changing variables
  • Wide Area Augmentation System (WAAS)
    • Augments satellite signals with wide area ground based signals
  • Local Area Augmentation System (LAAS)
    • Augments satellite signals with localized ground based signals, usually around airports
  • Inertial Navigation System (INS)
    • Stand-alone system using precise time calculations and gyros to determine position

Sim Pilot Notes

These notes highlight the differences between simulator and real-world flying. These differences are most often due to simulator limitations or specific VATSIM rules.

IFH - Chapter 9

  • Compared to real-world ADF, the simulated ADF tends to be very stable and well-behaved
  • If using the GPS for RNAV navigation care must be taken that the waypoints and procedures have been updated!

Tomas Hansson (This email address is being protected from spambots. You need JavaScript enabled to view it.)
Chief Flight Instructor, VATSTAR
DISCLAIMER: all information contained herein is for flight simulation purposes only.
March 2021

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