Fly Heading VS Fly Radial

Often we are confused about the fly and fly heading radial. This 2 things are completely different .

Fly Heading

We follow the heading as on our instrument from present position.

Basicly, all radial is outbound, or away from particular VOR, or known by the term”radials away from the station” while we can only fly inbound and outbound or close toor away from the VOR is specified.

Radial 077 BKY (116.25)

The sense is that we fly on radial 077 (outbound) of VOR called VOR BKY Barkway named not flyheading 077 after BKY VOR ..
i.e : We are given instructions to intercept radial 285 HLM1J HLM to perform SID runway25R/25L wiII, then if we set in the “course selector” 285, then you fly backcourse approaches, except when we set it to 105 (in can of 180 +105) , then the only thing youneed to do is select the LOC on your MCP .
Next, how to navigate VOR?
  1. Tune and identify. Tune the VOR frequency in the navigation radio. It will be listed on VFR and IFR charts as well as instrument approaches if it is a part of the approach. Identify that you have the correct station and the signal is reliable by listening to the Morse code identifier.
  2. Get your bearing. Determine which radial you are on by turning the OBS (Omni Bearing Selector) knob until the CDI (Course Deviation Indicator) needle is centered and you have a FROM indication.

From the picture above, you can see That the needle is centered and it Gives a FROMindication (small white triangle pointing to “FR”), so the aircraft is on the 254 degreeradial. It does not matter what the heading of the aircraft is, it is located somewherealong a line 254 ° FROM the VOR station. In order to fly to the station, Would you firsttwist the OBS knob Until the needle is centered and the white triangle points to “TO.”Note That this will of some 74 degrees, exactly 180 ° from the current radial. Now turnthe aircraft to this new heading and keep the needle centered, this will of take you tothe VOR station.
Intercepting a Course
  1. Fly the heading of the desired course. You can find the heading of an airway on either a VFR or IFR chart. Set the course into the OBS and turn the aircraft to fly that heading. Once established on the heading, note the position of the CDI. If it is to the right, your course is to the right. Likewise, if it is left, the course is left.
  2. Intercept the course. Turn 30 degrees in the direction of the CDI to intercept the course. Although 30° is most common and easy to use, you can use any intercept angle. For instance, if you are far enough from the desired course, it may take more than 30° to intercept the course before reaching your destination.
  3. Track the course. As the CDI moves close to the center, turn your heading to match the course. Keep the needle centered to stay on course. If it starts drifting left, turn left to get back on course. Tracking inbound (towards the station) and outbound (away from the station) radials is exactly the same, except you should get a TO indication when flying inbound and a FROM indication when flying outbound on a radial.
  4. Adjust for wind. If you find yourself blown off course by the wind, intercept the course and use a wind correction angle (WCA) of about ten degrees into the wind. If that is not enough, increase the WCA. If it is too much, decrease the WCA until the CDI centered.
Identifying an Intersection
  • Tune and identify both VORs just as before. Two VOR receivers are best, but you can still identify an intersection with one VOR by switching the frequency and comparing the radials of both VORs.
  • Set the OBS. Use the OBS to set the correct radials from each VOR. The radials will be displayed on VFR and IFR charts. On VFR charts, the arrows identifying the intersection point to the VOR, while the arrows on an IFR chart point from the VOR toward the intersection.
  • Wait for both CDI needles to center. While tracking the course on one VOR, watch the other VOR to see when the CDI centers. When both needles are centered, you are on the intersection.
  • Use DME to eliminate the need for a second VOR. While tracking the VOR radial, use the DME to find your distance from the station. DME distances will be displayed on IFR charts when it can be used to identify an intersection. For example, WARIC intersection is defined by the 238 radial from the VOR and the 21 nm DME fix.
  • Occasionally a localizer may be used in place of the second VOR. The procedure is exactly the same, but note that the localizer will be twice as sensitive as a VOR.

Credits goes to : Achmad Ferdi Iskandar


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