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martinlest2

How to use Back Beam switch

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Can someone kindly help me with the use of the BC switch? I seem to be veering off course whenever I press it. When coming in to land on a runway with no GS, what's the exact procedure in this a/c? I switch to ILS mode first, then press the BC, or leave HDG mode and press BC? And presumably I can't engage both APs and autoland under these conditions, can I? Have to descend 'manually'...Thought I'd mastered all this ages ago, but seem to be having problems with the RFP 747-200!!Thanks,Martin

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If you don't want a overly technical answer from a CFII, I'll explain how I understand it:BC reverses the way the A/P interprets and intercepts the beam when used on approach. Because you're on a back course (opposite end) approach you don't fly toward the deviation on the HSI or VOR1 indicator, you fly away from the deviation--this will bring the beam back to center. Because there's no glideslope on a BC approach, you must have the chart for the approach and fly the vertical profile just like you would on a VOR approach. There's a lesson on flying a VOR approach in the flight instruction section of MSFS that will fill you in on a VOR approach (the vertical profile is the important part).I hope that helps in some small way. If I've given you any bad information, I'm sure someone else will be along and correct it.Best of luck

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Hi. I don't normally have any problems with BC landings - the localizer brings me in line with the runway and I descend manually. But in the RFP 742 I seem to move away from the localizer as soon as I press the BC switch.Some time since I tried this, so will have to experiment again - I think I was just asking if there is any different procedure in this 742 that would account for my veering off course.Thanks.

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I think so, but to be honest I don't really remember! I'll check this next time. Thanks,Martin

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