Use of Back course

Back Course is an ILS Approach..but thje opposite of the published ILS Runway. If an airport only has one ILS Runway, say runway 9, the back course would be runway 27. You use it to navigate to the Glideslope and approach, but it is not as reliable as a published ILS.

The AP BC hold button is used so that the AP can correctly track the Back course signal for a Localizer Back course approach. LOC BC approaches don't have Glideslope signals.
➡ http://stoenworks.com/Tutorials/ILS%20Back-Course%20Approaches.html

I don't think I've flown a BC since my instrument training. However we didn't have any fancy BC button. I would just think to myself "I am the needle" whereas on a normal approach you would be thinking "the course is the needle."

So you guys mean - when the ATC says ''cleared ILS runway 27 approach, circle to land runway 9''. Is this the time I use the AP BC hold?

If yes do I press the BC after pressing the APP hold or I have to press only the BC hold?

Cheers

abmukh80 wrote:

So you guys mean - when the ATC says ''cleared ILS runway 27 approach, circle to land runway 9''. Is this the time I use the AP BC hold?

If yes do I press the BC after pressing the APP hold or I have to press only the BC hold?

Cheers

The proper time to track a backcourse is when you are cleared for a BC approach. The backcourse button should merely reverse the needle deflections (since you are flying a 'reversed' localizer) so you should press it before you intercept the localizer. You should really only be tracking a backcourse when it is published however it should work even when it is not published. (whether it does in the sim i don't know) They are published approaches like any. Now - Circle-to-land is simply that. On circle-to-land the idea is to get close enough to the airfield on a published approach that you have visual contact then remain in visual distance to field as you circle to land on another runway (for whatever reason - winds-closer to ramp, etc.) by basically flying a modified pattern to the active runway.

Example of circle to land: let's say that the only ILS is RWY 9 however winds favor 27. You may get a clearance "clear ILS RWY 9 Circle to land RWY 27) You fly the ILS as usual then keeping in mind the circle to land minimums (a certain altitude published on approach plate) you would fly a modified pattern to 27. (The exact point to start circling and exactly how far to remain from the field eludes me at the moment) And visually land on 27.

Example of backcourse: This airport now has a backcourse 27 approach. It is published. It is the same frequency as the ILS 9 but works in reverse because you are on the opposite side of the ILS transmitter on the field. This approach is exactly like a localizer only approach except the needle is working in reverse. You dont NEED the bc button if you can fly it in reverse. Or press the button to get reverse indication. I guess if you are using autopliot you should use it. (Does anyone fly instrument approaches manually anymore around here?? Lol.)